Chapter two (continued)
Becky and Other Students Talk About Interesting Things Over a Long Lunch Break

The Students Talk About Misleading Health Claims On Food Products and Other Things, and Joke About What's Good to Eat

Someone said gloomily, while tucking into a chocolate bar and a packet of crisps - though not both together, "I've heard about a lot of false health claims manufacturers make on food products. There was a programme on telly the other day about how some foods called 'low fat' foods really have more fat in them than the ordinary versions, or they have more fattening things like sugar in them, even though they have less fat. And sometimes the lower fat versions have more salt in them, since that compensates in some way for the fat, but it could be even more unhealthy. And the law says food labels are allowed to underestimate the amount of fat in a product by nearly a third, so foods can have quite a bit more fat in them than the labels say."

Most of the students were glad they'd finished their dinners and were only eating much smaller fatty things like chocolate, since a lot of their dinners had been quite high in fat, and they wouldn't have wanted to have been put off them. But still, the one eating the chocolate and crisps while complaining about foods being more fatty than their labels said they were didn't seem to mind eating fatty food at the same time. In fact, he swallowed it down enthusiastically.

The students were a bit shocked to hear what he said though. One said, "It's a pity you can't just trust what people say. But I've heard that some food manufacturers make health claims on food that aren't true too, more in America because they haven't got such tough laws about what's allowed as people in Europe have. I heard that one claim is that foods that have omega-3 fatty acids in them will help kids' brains develop and protect adults against heart disease. But I read that not all omega-3 acids are equally as effective, and some are in foods that might contain quite a lot but the body can't absorb them easily from them so it's not much better than having none, like flax seeds."

Becky said, "And it's not just foods. I've read that there's quite a bit of misinformation about health problems around, especially on the Internet. Some websites have got impressive-sounding names, but they've still got misinformation on them.

"One thing I've learned is that if you're looking for advice on the Internet, it's best to look at more than one article, and try and find websites that don't just have respectable-sounding names, but that belong to well-known respected organisations. But not just any respected organisations' sites; even articles on those, and even in science journals, get things wrong sometimes. A well-educated person can still get things wrong, especially if their expertise is in a different subject to the one they're writing about; for instance, someone who's really really good at biology might still make mistakes when it comes to chemistry, though at least it's less likely than someone who hasn't got much of a scientific background at all doing it, since they're more likely to know about things like ways of making sure studies are done well, so they'll know new information should be based on ones they can tell are good-quality ones.

"But it's easy to make the mistake of trusting what people say just because they seem respectable, like celebrities; I think people assume they must know what they're talking about. But if, say, they're giving advice on diet but haven't got a good background in biology, they might give bad advice, without either themselves or most of the people listening to them realising."

A few students pretended to hang their heads in despair in an exaggerated way. Others made loud crying noises and wailed, "Who can we trust?!" and one joked, "Shall we all just decide to give up and end it all now?" Then he shouted in a mock tormented voice, in an imitation of some comic actors, "We're doomed! All of us, doomed! We're all going to die!"

Several students walking by turned to look, puzzled. Becky said, "Those students walking past are staring at us! I bet they think we're talking about Armageddon or something!"

The other students giggled.

Then Becky quipped, "Well OK, at least we Know Some food's good for you, ... like chocolate! ... Oh hang on, have I made a mistake there?"

She grinned. Another student said with a smile, "Actually I've heard chocolate's good for you in moderation. ... But I suppose I'll have to be more cautious about believing reports like that now because of what you said, you spoil sport!"

Then one of the group said, "I heard on the radio that sometimes newspapers mistake one cause for another when they report things, so, for instance, they might say a study's found that people who eat caviar live longer and are healthier, and lots of people might think it would be good to eat caviar in that case; but it might really be that the people who eat caviar are the people who can afford to eat the most healthily, and it's really That that's helping them live longer and stay healthier."

Another student joked, "I don't think it costs a lot to eat healthily. Anyway, we know the basic rule: If you want healthy food, it's best not to eat any of that processed food but to eat all natural stuff. Everyone knows natural's best, ... you know, like worms and rats and things."

"Oh yuck!" several students said in unison, laughing. Then one said he'd known a man who went vegetarian for a few years, but then one day he was walking along a road after it had rained, and he saw a load of worms sticking out of the earth on a grass verge. Something in him gave him a craving to eat them. He thought, "Yum! Meat! Meat!" thinking they looked really appetising. But he managed to resist the temptation and went and got himself a bacon sandwich instead. He gave up being vegetarian after that.

The Group Discusses a Study That Supposedly Found That Vegetarians Aren't as Healthy as Meat Eaters

Then one student turned the conversation serious again by saying, "Did you hear about a study the papers reported on recently that said vegetarians have worse health and a lower quality of life than people who eat meat? It gave the impression that vegetarians have a higher risk of getting cancer and allergies and mental illness than meat eaters. I know someone who gloated over the thought that vegetarians aren't as healthy as meat eaters, since he hates it when vegetarians don't like it when he eats meat and he hears them talking about it being cruel and they think they must be healthier than him.

"But I read that there are problems with the study and it's misleading. For a start, it seems the people who ran it didn't think to ask the people they studied whether they got the poor health After they became vegetarians, or whether a lot of them decided a vegetarian diet might be good for them After they got the ill health! They assumed the vegetarianism must have caused the bad health, when it might have been mostly the bad health motivating people to become vegetarian! I've heard quite a few studies make that kind of mistake.

"Also, there were only 330 vegetarians in this study, and some weren't even completely vegetarian. That's not many, so the higher rate of diseases among people who ate little or no meat might have been pure chance, and maybe another study would find a higher rate among meat eaters instead.

"But I read that a newspaper - and not a tabloid either - had a headline that said, 'Vegetarians are less healthy and have a lower quality of life than meat-eaters', as if they just believed what the study reported without wondering about that kind of thing.

"According to what I read, most of the papers didn't mention what was wrong with the study, and it was even reported in one or two that vegetarians have a 50 % higher risk of heart attack, but the study itself didn't say there was a significant difference between meat eaters and vegetarians when it came to heart problems, so I don't know where they got that from.

"Another problem with the study was that the meat eaters were put into categories according to how much meat they ate and whether they ate a lot of vegetables, and people were asked which category they'd class themselves as being in, but they weren't told what would class as 'a lot', so some people might have thought they were eating a lot when other people might have eaten the same amount and thought they were just eating about an average amount. That would matter if the people who ran the study were going to make claims about, say, people eating a lot of meat having the lowest risk of disease.

"Also they didn't make any medical checks to see if people had the diseases they said they had, so people could have said they had illnesses they didn't really have. For instance, someone who'd been feeling down a lot for weeks might say they had depression, when in reality they were technically mistaken, because their problems wouldn't be medically classed as depression but something normal, because the reason for their misery was that they were grieving because one of their parents had just died. Nothing to do with vegetarianism at all!

"Or some might have said they were allergic to things because they thought they were, when in reality their bodies might have just been intolerant, and they'd never heard of the medical difference. I'd never heard of it myself till I read about this. But to give an example, some people who often get indigestion after they eat certain foods might be sure they're allergic to them, when really they've got some other problem that causes the indigestion, like an enzyme that isn't working well so it isn't digesting the foods well; or they might be foods that often affect people like that unless they're well cooked, because of toxins in them that need to be destroyed by cooking, like beans, that vegetarians probably often eat more of. So things like that would be classed as an intolerance or just a natural effect. That's different from having an allergy, which has to do with the immune system over-reacting to certain proteins in foods that it mistakes for threats.

"Besides, people often have allergies from the time they're babies, long before they even think about whether they want to eat meat or be vegetarian, so even if vegetarians did have more, it would likely be irrelevant, or it might sometimes mean that the person became vegetarian After the allergies made them think they ought to be more careful about what they ate!

"Also, the study was carried out in Austria and only included Austrians, so it could be, for example, that some processed meats are often prepared a different way there to processed meats here, or vegetables are grown with more toxic pesticides there; so people here couldn't be sure the findings would apply here even if there was nothing else wrong with the study!

"The place I got that information from was an NHS website with a feature called Behind the Headlines, which has information about all kinds of studies reported on in the media and how accurate they are. I think it's a good place to go to if you wonder how good a study you read about in the paper is."

One student scratched his head, and then twisted a bit of his hair around his finger, looking a bit lost. He said, "I don't know how you remember such a lot of detail at once! I couldn't keep that much stuff in my mind in one go. I can imagine starting off telling someone about it, and about ten seconds later, realising I can't remember the rest and having to stop, looking like a twit. I don't even dare tell Jokes in case I realise I can't remember them properly halfway through. I mean, I can imagine saying to someone, 'Why did the chicken cross the road?' and they'd say, 'I don't know. Why?' And then I'd realise I'd forgotten the punchline and have to say, 'I don't know why either'."

The other students thought he surely must be exaggerating, at least a little bit, and giggled.

One asked, "Have you ever noticed that vegetarians always leave their front doors and windows open in the middle of winter when it's snowing, as if they think it's healthier when really it must be half-killing them?"

"No," said another student.

"Neither have I," said the one who'd asked the question with a grin.

They groaned at the joke, though they had broad smiles.

The Students Talk About Reasons Why Reports of Studies in the Newspapers and Science Journals Can Be Misleading

Then one of Becky's friends started talking about studies again, saying, "Since we've been talking about badly-done studies, I read that there was actually a study done that found that a lot of the Reporting of other studies in the papers is inaccurate or could be misleading.

"It looked at quite a lot of reports, and found that often, any hopeful things about a study were exaggerated, while less promising or bad things were downplayed. So you might get a headline that says there's about to be a cure for some disease or other, and later in the article you might find there's actually no certainty that the research the article's about will find any such thing, that if it does it'll take years before any drugs come on the market, the positive effects of what the researchers studied were so small they could actually have just been a result of chance, and at the moment, the only thing being experimented on is mice or even just cells in a laboratory, not humans with the disease. The article might not even reveal all that detail at all sometimes, so even people who read it all will go away with the impression that things are more hopeful than they are.

"Or if humans are being studied, it was found that reporting often ignores the possible side effects and risks of a drug that scientists have found while doing the drug trials they've done, and just optimistically focuses on what good things the drug might do.

"The people who did this study of how well studies are reported said it's not all the fault of newspaper journalists, but it happens for a few reasons:

"Firstly, any brief summaries of the research the people doing a study give to the papers might make it sound as if the results are more hopeful than they really are, because they want their work to get noticed, and think the most positive things are the main things people ought to know.

"Then press officers who speak to the media on behalf of the universities and research institutes where the studies are carried out will make them sound as good as they can to try to capture the interest of the media, so some might leave out awkward details or sound more optimistic than they should, such as making it sound as if certain studies are promising breakthroughs, when they're only really little studies that just Suggest positive results but a lot more research needs to be done.

"Then journalists working for the mainstream media, who are after all under pressure to find stories and get them out to the public quickly, such as when they work for a newspaper that brings out a new edition every single day, often won't have time to research in-depth into a study, but will just read a press release put out by the press officer for the organisation where a study was carried out, and sometimes what the researchers said about it in the brief summaries they themselves gave the media, so they won't discover the less hopeful things about it.

"Also journalists say they over-simplify things in their headlines sometimes to get public attention, and because after all, headlines are too short to be detailed; so a headline might announce a breakthrough, when further down the article it does say any benefit for the public will be years away and the study was only carried out on rats or something.

"So I'm just saying don't get too hopeful too quickly when you read about these things, or don't get scared off something too quickly when you read about a problem; it's best to always look for more information first."

"You know, it's funny," said another student, "Newspapers seem to go in search of all the bad news they can find, and yet here, you're telling us they try to make news that isn't that good look better! Mind you, you might get some funny headlines if they wanted to report disappointing findings of a study instead."

He grinned, and then suggested some mock headlines:

"'Alzheimer's Disease Not going to be cured this year!' 'Chocolate Not going to be found to be good for the diet this year!' 'Computers Not going to be able to tell you you dropped your keys down the back of the sofa last night and that's why you can't find them this year!' 'Robots Not going to be able to tidy your house and do your ironing and feed the goldfish this year!' 'Chimpanzees Not going to learn to talk like humans this year!'"

One student asked, "Chimpanzees not going to learn to talk? What, have there really been studies where scientists have tried to teach chimpanzees to talk?"

"Well," said the student who'd been joking about it, "I did once hear about a man in France, I think it was, years and years ago, who brought a chimpanzee home to live with him, to see if it and his two-year-old son would learn to talk like humans together, wondering if the chimpanzee might be able to gradually learn like the boy did as he played with him, imitating him and gradually making noises more and more like words, like the boy did, till he could say things. He gave up the idea after he got worried because the boy started making noises more and more like the chimpanzee instead."

"Eek! The thought of a boy turning more and more like a monkey's making me cringe!" said one student.

"Come on!" teased another one with a smirk. "Aren't boys a bit like monkeys anyway?"

"Oy!" said a few of the male students, grinning.

One student got serious again, saying, "I've heard some bad things about some scientific studies themselves. I read that often science journals publish badly-done studies, before newspapers even get hold of them.

"I read that there's what's supposed to be a protection mechanism that prevents a lot of bad studies being published called the peer review system, where when scientists sends studies to a journal hoping to get them published, other scientists look at them and see if they can find anything wrong with the study methods that were used that would mean the findings can't be trusted, for example if there was maths involved and there are mistakes in the calculations, or if the number of people studied was so small the results couldn't possibly prove anything definite because studying different people might have found different things, like if there's a study that supposedly finds that people from hot countries are more likely to get a particular genetic disease, but people from only one hot country were studied, and a lot of those were from the same area so they might well have been related so they had similar genes, so it wouldn't be surprising that they'd get the same genetic disease, and it wouldn't prove what the study claimed it did at all.

"So it's good that the peer review system exists to try to weed out bad studies.

"But if a study seems to have been done well, the scientists doing peer reviews aren't going to be able to tell if the findings are really true or not.

"And the system doesn't always work as well as it should. There are quite a few reasons for that. It's partly because some reviewers end up reviewing papers by their friends, so they're less critical of them than they should be, or they can end up reviewing papers written by rivals who they're in competition with to get recognition for discovering certain kinds of things, and they give them unfairly critical reviews to try and stop them being published so as to keep them behind in the competition, or some can even steal their research findings and claim them as their own in later papers they write themselves. Hopefully those things don't happen often. But there can be other problems too.

"And I read that some useful scientific findings were rejected by scientists doing peer reviews at first, even papers by scientists whose findings went on to win them Nobel prizes. And I heard that some peer reviewers can't believe surprising or new findings because they contradict things they've always believed before, but they've turned out to be true.

"And it's been found that research done by scientists who work at universities with the best reputations can be passed as worthy of being published whether it's really that good or not. An experiment was done where some papers from places with the best reputations that had been published in journals were retyped and passed off as coming from unknown authors at places that were less well-known or made-up, and they were criticised and rejected for publication! And one medical journal gave some scientists who did peer reviews papers to check that had had errors deliberately put in them, and most of them didn't find a lot of them, even though they were told they were being tested.

"From what I've read, sometimes it seems journal editors let their peer reviewers know they don't want them to look too hard for mistakes, or choose reviewers to check a scientific paper who they know will be enthusiastic about the findings so they won't feel like looking too hard at it because they won't want to find out it isn't true after all, because a paper seems so interesting it would seem a real shame not to publish it, because if they do print it it'll cause more public interest in the journal, so they'll end up with more paid subscribers to it."

One student said, "Come on, things can't be that bad!"

The student who'd been talking said, "Well, I think things vary a lot. I've read that some journals have got much higher standards than others. But even then they can let bad science in sometimes. By the way, the journals people have to subscribe to are ones where you can find the beginning of articles online, but if you want to read the rest you have to pay. I think a lot of people just assume the articles in them are respectable and well-researched, but actually it's been found that possibly even the majority of study findings that are reported in at least some of them turn out to be false.

"There was one paper sent to one of the most respectable ones where scientists had made mistakes and claimed that some bacteria had been found with arsenic in their DNA. That would be a real surprise, if something that normally poisons people and animals was used to help a certain species actually survive! And it would have been even more surprising than that, because it was claimed that the bacteria used arsenic instead of a chemical every species needs to live, phosphorous. But instead of treating the paper with extra caution, it seems the people at the journal it was sent to got excited at the thought of how interesting the findings were and how much interest from journalists and the public there might be, and published it, despite there being lots of errors in it that peer reviewers should have found. The peer reviewers did question the study authors a bit, but not about the really important things, it seems. It turned out that the bacteria were a lot less sensitive to arsenic's effects than humans, but it wasn't a part of them."

One student said, "Come on, things can't be all bad; I bet you're just anti-science! I knew someone who said he was anti-science once; it was weird! He used to say he thought science was evil, but I used to think, 'Hang on, it's science that's brought you a lot of the things you love using, like your computer and your kettle and television and telephone, ... plus the drugs you enjoy taking that've stopped you realising how daft your views are! Would you like to go back to living in the stone age?'"

The student who'd been talking about faulty science said, "I know science has done a lot of good for us. I'm just saying that among the good studies of new things, there are a whole load of bad ones, or so I've heard. In fact I heard that a lot of scientific studies that get published are later found to be wrong and full of mistakes and even deliberate biases, where things like certain drugs are made to look better than they really are by being compared to ones that aren't very good, and things like that. And it's serious, because it includes studies of drugs and lifestyle that doctors rely on to give people advice and prescribe them things. So some advice can change over time. I heard it was once recommended that people should drink a lot of water during vigorous exercise, but now it's been realised that drinking loads can actually be damaging.

"But I do know there's still a lot of exciting new science out there."

One student said, "That stuff about study findings that are wrong sounds bad! But hopefully doctors are educated enough to know to wait till they know a drug's got a good reputation before they prescribe it. And I can think of studies I'd Like to be wrong! If scientists ever announced that exercise isn't good for health after all so people never have to do any, I'd start celebrating with my feet up and a massive box of chocolates! I don't like exercise!"

The student who'd just been talking about bad studies chuckled and said, "Somehow I think you can bet that'll never happen!"

"Yeah, shame!" said the student who'd just mentioned it, smiling.

But one said, "My older sister's got an exercise bike and a fold-up treadmill in her house. She doesn't like exercise either, but she doesn't mind going on those; she says it feels like much less of a slog when she goes on them while she's watching television or listening to comedy programmes or interesting things on the radio. And I know someone else who says she makes exercise feel like less of a slog by listening to music in the background. And I think some people find it's less boring when they exercise with other people in a group, or just with one companion, or out in the sunshine ... when there is some!"

One student said, "I like to put comedy programmes on while I'm doing exercise. Sometimes I exercise to serious radio programmes too though. One day, I thought I ought to be getting down to doing some exercise, but I didn't feel like it, and I thought, 'Maybe if I eat some chocolate, it'll perk me up a bit so I'll feel more in the mood to do some'; but then I realised that would be defeating the object of burning off calories. I ate some anyway though.

"I'd been planning to listen to a couple of programmes on the radio about people dying and things while I was exercising, but then it occurred to me to think, 'Maybe I'd feel in much more of a mood to do my exercise if I was listening to a comedy programme, instead of programmes about people dying!'

"Actually, I've noticed it feels like less of a slog when I'm listening to comedy than it does when I'm listening to serious things, for some reason."

Another student grinned and joked, "Let's hope scientists don't announce one day that they've discovered that exercise only does anyone any good if it feels like a slog!"

They laughed.

But then one said, "Well if they do, we can always just wait a while, since other studies might come along that disprove it, so we might be given different advice next year!"

They grinned.

The Group Talks About Official Advice Changing and Even Reversing Over Time, Such As On First Aid Courses

Then one turned the conversation serious again by saying, "Do you know, I've heard about advice changing over time. I heard that anyone who's done a first-aid course should do another one every so often, because sometimes it's discovered that some of the information that used to be given to people isn't that good after all so the advice has changed, or sometimes things that used to be used to treat people were found to do them harm in some ways, so courses advise against them now.

"I found that out from a man who teaches first aid, who gave us an example, saying some first-aid courses used to teach that it's good to put iodine on a cut or a graze because it kills bacteria that might cause infection otherwise. But nowadays they think ordinary water's much better for cleaning out cuts and grazes, because though iodine's good at killing bacteria, so if the skin isn't broken it can be good to use, which means it can be a good safeguard doctors use to cleanse the area of skin they're going to cut before doing surgery, on broken skin it kills skin cells, so a wound with it on can take longer to heal. And other things they used to use do that too; I heard that some people were advised to use rubbing alcohol because it kills bacteria, but it stings because it's killing healthy tissue.

"So even if you think you remember everything you learned on a first-aid course, it's good to do new ones. And they can refresh people's memories anyway, which can be good, because I think people can forget more than they thought they had over time.

"And I heard that quite a few old home remedies that some people trust can do more harm than good too. I'd never heard of it before, but I read that some people advise people to put butter on burns, but that it's not really a good idea, because bacteria can build up where it is and cause infection, which damages the area even more. It's best to run a burn under the cold water tap or get it bathed in cold water some other way as soon as possible, and then if it's really bad, of course go to hospital.

"I think parents especially should maybe look at information on respected sites on the Internet to find out the latest advice.

"But I think all these things were found out after a lot of scientific studies, so you've got to take Some notice of them."

The student who'd been talking about problems with studies said, "Yeah, I didn't say none of them are any good. I was just saying there are a lot of ones that are later found to be wrong by other studies out there. So it's best not to believe them all."

He smiled and said, "Actually you'd have to believe contradictory things if you believed them all, since you'd be believing the ones that said something had been discovered, and the ones that said it hadn't been after all at the same time."

The Students Talk More About the Quality of Science Journals, and One Tells Them About Scandals Involving Some

He grinned, and so did other students. Then he got more serious and said,

"Anyway though, to carry on what I was saying before: I was talking about science journals where studies get published. Some of them are a lot better than other ones for checking the quality of the new studies scientists who do them send them hoping they'll be put in them. It seems there are some where any old thing can be published, so any member of the public who doesn't know that might be assuming they're reading something important because it comes from a journal, when really it's rubbish."

One student said, "Realistically though, there's still a lot of good science going on. I mean, just think of the new technology that keeps coming along! My mum said that when she was born, they didn't have mobile phones, they didn't have the Internet - they didn't even have personal computers! They didn't have microwave ovens; they didn't have high-factor sun cream, and they couldn't do a lot of the medical procedures they do now with anything like the success rates you get now."

A friend of hers imitated the way she was talking and joked, "They didn't have razor blades; they didn't have televisions; they didn't have cars; they didn't have plastic; they didn't have bread; they didn't have knives; they didn't have forks; they didn't have houses; they didn't have clothes; they didn't even know how to make fire!"

The student who'd started talking about technology developing laughed and said, "Oh come on! My mum's not that old!"

The students all laughed.

The one who'd been talking about bad studies in science journals said, "I'm not saying there isn't a lot of good stuff out there; I'm just saying some of the studies that get passed off as good science aren't much good at all.

"Besides journals that are paid for by people subscribing to have access to them, there are other kinds of journals where scientists themselves pay to get their papers published in them, and the public can read their findings online free. Some are of a much better quality than others though. It seems a lot of those journals say they have peer review processes, where a few scientists look at every paper people send in to be put in a journal, and either recommend it's accepted, advise that it should be rejected, or tell the scientists who sent it in to make certain alterations and then try sending it in again. But some journals only really pretend to do a good job of putting new scientific papers they're sent through that process, since every paper they reject means less money coming in. I heard that some are even run by people who are really criminals just out to make money. I heard there are an increasing number of those coming out of Nigeria and India.

"Some employees at some of the ones that aren't very good keep emailing scientists inviting them to send papers to their journals, hoping to make more money. I heard one scientist sent back a fake paper with a title like, 'Get me off your annoying mailing list!', and it actually got published! And another one sent back a paper made up by a computer using a program that generates text made to look like science papers but that are really gibberish. It said things like, 'We removed a 8-petabyte tape drive from our peer-to-peer cluster to prove provably "fuzzy" symmetries’s influence on the work of Japanese mad scientist Karthik Lakshminarayanan'. But that got published too! It seems that as long as you pay, you can get anything that looks vaguely like a science paper published in a few of them!

"Some journals are much more respected than those and more likely to have good-quality science in them. But even people who work for the best science journals don't always make the best decisions about what's worth publishing and what isn't. And the opinions of even good peer reviewers about a paper can change over time, when new information comes to light. And there tend to only be three people reviewing each paper. So it seems some people automatically assume papers that have been peer-reviewed will be more accurate than ones that haven't been, and they just assume they'll be trustworthy, when that isn't always the case.

The Student Talking Tells the Others About Funny Comments From Scientists, and Then They Joke About Wacky Study Ideas

"Mind you, some peer reviewers are pretty critical of some of the papers other scientists send in about the studies they've done, so it seems that a lot of them do try and do a good job. I read some funny quotes from scientists doing peer reviews for journals. I can't remember many of the exact quotes now, but they were things like:

"'The biggest problem with this manuscript, which has nearly sucked the will to live out of me, is the terrible writing style.'

"'I suggest that someone should be setting up a fund that pays for the red wine reviewers might need to digest manuscripts like this one.'

"'Season’s Greetings! I apologise for my slow response but a roast goose prevented me from answering emails for a few days.'

"'This is a long but excellent report. It hurts me a bit to have so little criticism of a manuscript.'

"'I suppose I should be happy that I don’t have to spend a lot of time reviewing this dreadful paper; however I am depressed that people are performing such bad science.'

"'Well, I did some of the work the authors should have done!'

"'Reject! More holes than my grandad’s string vest!'

"'I have to admit that I would have liked to reject this paper because I found the tone in the Reply to the Reviewers so annoying. It might be irritating to deal with reviewer’s comments (believe me, I know!) but it is not wise to let your irritation seep through every line you write!'

"'The writing and the way the information was presented are so bad that I had to leave work and go home early and then spend time to wonder what life is about.'

"'Done! Phew! I didn't want to have to think about bacteria in faeces and constipation over my holidays, but I know it was my duty!'

"'My heart sinks when I have to review papers from this group as I know my response is most likely going to be as long as the paper.'

"'Although it seems like they have taken on board the peer reviewers comments and made alterations to their paper, in some ways it's less clear than the previous version!'

"'I would encourage re-submission of a shorter version, deleted of ecological fantasies.'

"'Is there a chance you could send me any Good papers, at least once in a while?'

"You can find quite a lot like that on the Internet. Mind you, some weird things do still get through to be published by journals. I read there was one study that claimed that it had been found that pigeons can tell the difference between good and bad paintings children do. I don't know how they came to that conclusion! Or why they thought that was worth studying in the first place!

"And there was one that supposedly found that rats can't always tell the difference between Japanese spoken backwards and Dutch spoken backwards, and another one that found that mosquitos are just as attracted to a smelly kind of cheese as they are to foot odour!"

"Who'd want to study things like that!" said one student, laughing.

Another student joked with a grin, "Hey imagine if a science journal published a study that announced it had found that eating junk food quickly ages the brain, and said the scientists who did the study knew that because they split sixty young people into two groups of thirty, and gave one a diet of vegetables for a few weeks while they gave the other one a diet of junk food, and all the while they played both groups music from the 1960s, which they'd all said they weren't that keen on before, and during all that time, the people on vegetables protested about having to hear it more than the people on junk food did, so the study authors thought it must have meant the people on junk food were happier to hear it, which must have meant their music tastes were becoming more old-fashioned, which must have meant their brains were becoming like the brains of the older people who grew up in an earlier era and were brought up with that kind of music so a lot of them like it best, which must have meant their brains aged about forty years in a few weeks!"

"Ugh! That would be a spooky study!" said one student. Then he said with a chuckle, "I wonder if anyone would believe it! Actually it would be more likely to mean the ones on junk food enjoyed what they were eating more so they were in a happier mood, so they could tolerate things they weren't keen on more!"

The students giggled. One said, "Or it might have just happened by chance. Or if they were allowed to eat as much junk food as they liked, they might have all been too busy stuffing their faces to have their mouths empty for long enough to have complained about anything!"

Another student said, "Hey imagine if a science journal reported that scientists had found that wrapping your head in seaweed for three weeks is a cure for baldness. I wonder how many people would try it!"

One student said, "Wow, wouldn't you be disappointed if it didn't work after all that! Mind you, I can imagine the study finding might be true if it found that baldness is no longer a Problem for people who've wrapped their heads in seaweed for three weeks, because they'd probably end up with a different perspective on things, you know, like, 'I used to worry about going bald and becoming less attractive to women, but after walking around town and going to work with my head covered in soggy smelly seaweed for three weeks, I've realised that merely going bald is nothing to worry about after all!'"

The students giggled.

One said, "Imagine if a study reported that eating a spoonful of sugar mixed with cream cheese could help people live twice as long. You might get parents insisting their kids ate it every day, telling them they could live to 200 or so if they did, and the kids might say in disgust, 'I don't really think I Want to live that long if it means I have to eat This stuff every day!'"

One student said, "And just imagine how bad it would be if someone did eat it every day for seventy years, despite hating it, only for a new study to come out saying it didn't have any effect on how long you lived after all!"

The students grinned and cringed, and one said, "Ouch!"

Then one said, "Imagine if a science journal claimed that eating a cream cake twice a day helped you lose weight because it speeded up the metabolism so you burned calories faster! Wouldn't it be wonderful if doing that really was good for you! But I can imagine if you tried it, when you were as round as a balloon, you might realise it wasn't working after all!"

Becky chuckled and said, "Yeah, you'd have to burn fat Very Very fast to lose weight on a diet like that! Hey imagine if people had a plug in their bodies and they could pull it out every so often and drain some fat out, and the more they exercised, the more fat accumulated in the part of the body where the plug was to drain out! I suppose you could put your fat on toast if you ran out of margarine."

The students laughed, and one said with a grin, "Ugh! Don't be disgusting!"

One Student Worries About Possible Harm Reports of Faulty Studies Could Do, and They Talk About Eating the Right Amount of Protein

The student who'd brought up the subject of bad studies being hyped up in newspapers earlier had been grinning along with them, but then he stopped and said, "This thing about badly-done studies making false claims is serious though, because some studies cause health scares, and if there's information around that proves they can't have been good studies after all but it isn't being reported, people might never know.

"I mean, imagine if the newspapers said there was a study that somehow found that the more protein babies and toddlers were given, the more likely they were to develop allergies, so it was best not to give them any fish or meat or dairy products: Other scientists might do studies to see if there really is a link, and none of them might find one. But if their studies aren't publicised, loads of parents might believe the false study findings and do their best to make sure their kids didn't have any animal products whatsoever. The problem with that is that people need protein, especially if they're still growing, and also, Vitamin B12 is only found in animal products, so people who give them up altogether can go short of it."

One student smiled and said, "Now hang on! If parents thought they ought to eliminate all animal products from their baby's diet, mums would have to stop breast-feeding them, which they would never do, - well unless they put them on a vegetarian substitute instead, - because they'd know that then their babies would starve, which - let's face it - would be even worse for their health than an allergy! But hang on! No mum would believe that a natural substance in their own breast milk was going to give their baby allergies!"

The student who'd brought up the idea said, "Allright, maybe it's a bad example. But the point I'm making still stands: OK, just imagine if a study said that all protein Except the protein found in breast milk put babies or toddlers at an increased risk of allergies. Mums of babies who'd been weaned onto solid food might stop feeding their babies any animal products, and then they might go short of protein and vitamin B12.

"When people go short of vitamin B12, the body finds it more difficult to make red blood cells, because vitamin B12 helps with that, and when the body can't do that so well, people can feel tired and weak. If the deficiency gets worse, people can start feeling depressed and irritable and not so good at thinking, and they can bruise and bleed more easily. And it can even cause nerve damage if it carries on a long time. And when people don't get enough protein, they feel weak and tired too, and if they get injured it can take longer for them to heal."

One student said, "That's scary!" Then he joked, "Mind you, you're telling us scary stuff about what giving up meat and things could do; you don't happen to work for the meat marketing board, by any chance?"

The student who'd been talking about vitamin B12 and protein deficiency said, "No. I'm only using meat as an example of what might be the subject of a scare story in the papers anyway; it could be any number of things."

One student said, "Actually, it wouldn't be as easy as all that to go short of protein; even if you don't get it from animal products, a lot of other foods contain things the body can use to make protein, so if you eat a combination of foods with parts of what go to make up protein in them, it can put them together to make proper protein. Like if you eat lentils or chickpeas or beans with nuts or rice or pasta in the same meal, or even just on the same day, the combination of protein building blocks in the different types of food makes up full protein.

"And I read that most people actually get too much protein in their diets, which can put a strain on the kidneys, especially if they're not working as well as they should, because they have to filter the protein the body doesn't need along with the other waste from food they deal with out of the body. So a lot of people could probably do with eating less of it."

The one who'd been talking about scare stories blushed a bit and said, "That's interesting. But like I said, I was only using that stuff about protein as an example. I didn't say it was a Good example."

They giggled. But then one student said, "I doubt the papers would be irresponsible enough to report anything that could lead to anything as drastic as you think happening!"

The student who'd suggested the idea said, "Maybe not; but if the study was done by someone who seemed respectable, like a professor at some institute with an important-sounding name, who knows! I mean, maybe they wouldn't report anything that might lead to anyone doing anything that drastic, but if they thought it might be really important they might. Or people might do something more drastic than was intended; I mean, a study that found that having lots of protein increased the risk of food allergies wouldn't mean it was best to have none, would it, but some people might think it was best to give their babies none to be on the safe side, only it wouldn't be being safe really. Anyway, like I said, that was only an example I made up."

The Students Talk About Allergies, and Then Joke Around a Bit

One student asked, "What really Does cause food allergies?"

Another one said, "I don't think anyone really knows yet. But I heard allergies have gone up a lot in the past few decades, so it seems it's probably sometimes to do with something people are doing nowadays that they never used to do before, or something that's changed about the conditions people live in. Some people think it might be to do with pollution, or certain common chemicals like some pesticides."

Another student said, "That reminds me: I've never had hay fever in my life, but a couple of years ago they were re-tarmacking a road near me in the summer, and I kept wanting to sneeze and blow my nose, as if the tar fumes were causing the pollen to aggravate it. Or it could have been just the tar fumes causing it, but I don't think tar ever did that before."

One student said, "I know someone who's got such a severe allergy to shellfish, one day she ate some in a restaurant, and immediately her tongue swelled up and she had to go to hospital. Mind you, I think some people might have less severe allergies without knowing, and they might not feel very well without knowing why, and they only ever find out it was a certain kind of food causing the symptoms when they don't eat it for a while and they go away."

One student joked, "I think I might have had an allergy to school dinners. They brought me out in a feeling of disgust!"

The students smiled, and one said, "I remember one day at school, one boy came to a maths lesson and announced to the teacher, 'I can't come to maths any more; my doctor's told me I've got an allergy to it and if I carry on doing it I'll get brain damage!' The maths teacher didn't believe him and asked if he had a medical certificate to prove it. When the boy said he didn't, the teacher made him carry on doing lessons."

The students grinned. One said, "Nice try though!"

Another student turned the conversation serious again, saying, "My sister's got a friend who often feels tired. I wonder if that could be to do with a food allergy. I did hear about one person who said he used to feel all groggy and as if his brain wouldn't work properly, but he gave up dairy products and then felt better. Maybe she could try experimenting with giving certain foods up to see if she feels better."

"Maybe," said the student who'd talked about allergies becoming more common. "Mind you, I've heard that people shouldn't do anything drastic without consulting a doctor first. I mean, for one thing, their symptoms might not be anything to do with food and the doctor can test other things. But for another, I've heard there's a problem with some people giving up certain foods because they wonder if they're allergic to them, and then getting malnutrition because they've accidentally given up things they need to eat to stay healthy. But if people speak to someone who knows about everything people need in their diets first, they might suggest alternative foods with the same nutrients in they can start eating when they give others up."

One student joked, "It's not just foods that can give people allergies though, is it. I think I've got an allergy to work! If I do too much of it, I get tired! Mind you, I've got a worse allergy to exams! They bring me out in a cold sweat! ... Well, I think one might have done, once. Hey, do you think if I told the tutors that, they'd let me off work and exams and just give me a good degree on health grounds?"

The students giggled, and one said with a grin, "Somehow I doubt it!"

A Student Tells The Others About Some Problems Allergies Cause, and Which Foods People are Most Likely to Be Allergic To

Then the conversation turned serious again as one student asked the others, "How would you know if you've got an allergy? I mean, what kind of problems do they cause?"

The student who'd been talking about them said, "Well I heard they can cause symptoms like rashes, eczema, swelling around the lips, tongue, eyes and face, stomach pain, vomiting and diarrhoea. Occasionally they're really serious and life-threatening. Other things can cause those symptoms too though, so it's not always easy to know what's causing them.

"I read that any food can cause an allergy, but that about90 % of them are caused by just about half a dozen foods, eggs, milk, soya, wheat, nuts and fish. And citrus fruit causes quite a few too. Apparently most children grow out of allergies, so that's good. But they don't all, and it's possible for some people to get them later in life.

"According to what I read, some people can be allergic to fruit and vegetables, but those allergies are usually mild and just cause itching or a rash around the mouth and lips. Cooking some fruits and vegetables stops them causing the problem, though it doesn't stop all vegetables causing it."

"And I read that food intolerances can cause quite severe symptoms as well as actual allergies. I heard that quite a lot of people are gluten-intolerant, and gluten isn't just found in wheat, but other grains like barley, rye and oats too. So it's just as well there are gluten-free products around, and there's a lot you can eat that hasn't got gluten in it anyway."

The Students Joke About Doing Wacky Things In Shops

"What do companies who make gluten-free products use instead of gluten?" asked one student. Then without waiting for an answer, she joked, "Hey imagine if supermarkets advertised certain products as alternatives for people with allergies, but they had strange ingredients that they didn't always tell people about, so instead of steak pie they sold snake pie, and instead of cheese and onion crisps they sold fleas and onion crisps, and instead of lamb stew they sold jam stew, and instead of rice pudding they sold ice pudding, and instead of frozen peas they sold frozen bees, and instead of teabags they sold peabags!"

The students giggled, and another one said, "Or just imagine if it was a pet shop, and when someone asked for a cat they were sold a rat, and when they asked for a dog they were sold a frog, and when they asked for a hamster they were just sold a bit of ham, and when they asked for a parrot they were sold a carrot."

Another student said, "Hey imagine going into a pet shop and asking to buy a cow, or a seagull."

Another student said, "Or what about going into a pet shop and asking to buy a tractor, or a jar of coffee."

One student said, "Imagine going into a pet shop and asking for a bag of rabbit food and a jar of coffee! They'd probably think you were going to give your rabbit coffee to drink instead of water."

Another student said, "Yeah, or they might think you were planning to eat rabbit food for breakfast instead of muesli. ... Or they might think you were just daft!"

"Yeah, probably!" laughed a couple of students.

One said, "Imagine if you went into an electrical goods shop, and you went up to a computer and asked a shop assistant if you could buy one key off the keyboard, or you went up to a radio and asked them if you could just buy one of the knobs on it."

"It would be even weirder if you were actually asking the computer or the radio those questions!" said another student.

They all laughed.

One said, "Hey imagine going into a supermarket, going up to a till and asking the person at the checkout if you could have one single prune, or one single vitamin C tablet, and asking them to wrap it for you."

Another student said, "Yeah, or imagine taking a jar of coffee up there and asking if you could just have one teaspoonful out of it, and if they could wrap it for you. Or imagine if you took a box of teabags up there and asked if they'd mind opening it so you could have just one teabag!"

Another student said, "Or imagine if you took an egg up to the till and said you only wanted half of it and asked if it would be allright if you cracked it there and just took the half you wanted!"

Another student said, "Or imagine if you took a bottle of fizzy drink up there and said you didn't want to buy the drink, but you'd like to buy the label, if only they could take it off the bottle and turn it into a paper aeroplane for you."

"I don't think you'd be very popular!" said one student, grinning. "You might even find yourself being thrown out by security!"

Another student said, "But just imagine if when the security person came to throw you out, you said to them, 'Ah, perhaps You can help me! I've been looking for the motorbike aisle everywhere! Someone told me the cars and motorbikes are next to the strawberries, but I can't find them at all! I was hoping to drive off on one today!'"

Another student said, "Or imagine if you said, 'I've noticed all the chickens in here are all dead! Most are even frozen! How could you have let that happen! It's an absolute scandal! This is the worst pet shop I've ever been in! I'm going to report it to the authorities!'"

The Students Talk About Allergies to Pets and Ways of Handling Them, and End Up Joking Around as Usual

They giggled. But then the conversation turned serious again, as one said, "I've got a relative who's got an allergy to chicken. Or it might be to one of the chemicals it's washed in before it gets to the shops."

Then one student said to the one who'd been talking about allergies, "Hey, you listed what you said were the most common allergies, but you didn't mention allergies to pets; I've heard that they're common too." After swallowing a mouthful of chocolate with obvious enjoyment, she said, "I've got a friend who's got one. I read that allergens - the things some people's immune systems have a problem with so they set off allergies in them - are types of proteins, and in animals, they come from body fluids like urine, saliva and sweat. They get all over an animal's hair and skin from their saliva when they lick themselves clean, and then when some of their hairs fall out and some of their skin cells fall off, they'll be coated with the allergens so they can be spread around a house and cause allergic reactions, like asthma attacks. And if they have long hair, the hair can pick up other things that cause allergies in some people like pollen, dust mites and mould spores, so when the hairs fly around the place, they cause problems too.

"Little animals like hamsters can have the proteins in their body fluids that cause allergies, and they fly around the room when the hamsters kick stuff with their body fluids on it up by running around their cages. Some kids with allergies to that stuff have little pets like that in their bedrooms, and they get things like asthma, and the family doesn't know why, but that's what's causing it. So it's best to keep pets out of bedrooms. That's what I read anyway.

"The article I got that information from said that short of giving the pet away, grooming dogs outside to get rid of loose hairs, and giving cats a bath once or twice a week, can reduce the allergens they can spread around a lot. And using powerful vacuum cleaners on carpets can help a lot too."

"Oh yuck!" said one student. Another made a face and said sarcastically but with a grin, "Thanks for that. Just what I needed, right in the middle of my dinner!"

The one who'd been talking about allergy symptoms before said to the one who'd brought up pet allergies, "That's interesting. But when I mentioned common allergies, I was talking about food allergies." She grinned and joked, "Your friend doesn't think of pets as food, does she?"

The one who'd been talking about pet allergies joked, "Actually she does. I had seven big pet dogs in my room, but she ate them all, one straight after another! I didn't tell anyone, because we're not allowed pets in our rooms and I didn't want to be found out. I used to walk them at night hoping they wouldn't find out I had them, and sometimes they all barked and one of the university staff knocked on the door to find out what the racket was. I used to quickly shove my dogs into my wardrobe, and then open the door and tell the person the noise was me doing voice training exercises; I said I was learning to sing, and my voice trainer had told me it would help me progress from totally atonal to semi-decent if I spent a lot of time barking.

"Anyway, one day my friend came around, and she said my dogs looked yummy, and then she picked one up and just ate it, right there and then. Then she picked all the others up one after the other and ate those too. When she'd finished, her stomach was so huge, she was standing at one end of the room and it reached right to the other. She couldn't get it out the door; in fact, we couldn't even open the door because there wasn't room. We had to call the fire brigade, but they couldn't help, so they called demolition experts, and they had to demolish the building to get us out! The fifty students who lived there had to be evacuated with all their belongings and accommodated in local hotels till they'd built a new hall of residence to house us in. It took months!"

"Wow," said one student with a grin. "I wouldn't mind eating a dog if it meant I could live in luxury in a hotel for months!"

The one who'd just told the joke story said, "But You probably wouldn't be put there. My friend who ate all my dogs wasn't housed anywhere else; she couldn't fit through the door of any hotel. But she didn't mind; her stomach was so massive that she slept on campus outside the lecture theatres, and she was still really warm, because when she lay on her stomach, it bulged up all around her and enclosed her over the top, so it was like a massively thick sleeping bag. Even in the winter it kept her really warm."

"You're crazy!" said one student with a chuckle.

"I know!" said the student who'd told the joke story with a smile.

One Student Tells the Others Quite a Bit About What Nutrients Are In which Foods

Then she said to the person who'd brought up the subject of food allergies, "sorry, what were you saying about the most common food allergies?"

She replied, "I was saying that they say if you don't feel well and you decide to go on a strict elimination diet where you give up lots of foods in the hope you're giving up what's causing your symptoms to see if you get better, it's best to see a doctor first. That's probably so they can do tests to see if other things might be causing the symptoms instead, and maybe also because if you're going to give up foods it's healthy to eat, it's best to make sure you're getting the nutrients in them from other things instead.

"I mean, I've heard you're supposed to eat foods from several different categories of food to stay healthy: fruit and vegetables, seeds and nuts, dairy products, oily fish, and grains. And if you give up one kind of healthy food, it's sometimes best to find out what nutrients are in it, and then check to see if you're either getting those from something else you're eating, or what other foods you could get them from instead.

"I mean, for example, if a person wondered if they had an allergy to eggs, they might find out that eggs contain vitamin D, which they might go short of without them if they're not getting enough sunshine. People need vitamin D because it helps keep the nervous system and immune system healthy, as well as helping the body absorb calcium and phosphorous, which it needs for keeping bones strong. Some scientists think it's vital for helping to keep the brain healthy in later life, and can help reduce the severity of asthma and the risks of developing some kinds of arthritis. And they think it does other good things too.

"There aren't that many foods that contain vitamin D. Oily fish like sardines does, so anyone who gives up eggs might eat more of those, if they know they're not allergic to those too.

"Mind you, they do say people shouldn't eat loads of sardines, since they can be contaminated with small amounts of pollutants from the seas, although sardines will probably contain less than some other fish, because they don't live so long, I don't think, so there won't have been as much time for pollutants to have built up in their systems before they're caught. I've heard it's still OK to eat most other oily fish in moderation though, since it would take some time for any small amounts of pollutants that might be in them to build up to harmful levels in a person's system.

"But anyway, sardines contain decent amounts of vitamin D. And sunshine on the skin causes it to make vitamin D, so it's worth getting a decent amount of that too. It's good that there are high-factor sun creams that protect the skin against getting sunburned and getting skin cancer, but it's best if people often spend short amounts of time in the sun without any on, so they can get vitamin D from it.

"Anyway, talking about eggs again, they contain other vitamins and minerals a person giving them up might want to think about replacing in their diets, besides vitamin D. I mean, people don't have to be all that worried, because a lot of vitamins and minerals are found in quite a few foods, so chances are they're eating them in other foods already. But it might be worth checking.

"Another thing it's important to have in the diet that's found in eggs is vitamin E. That's also found in nuts and green vegetables. It helps cells communicate with each other well, and it's an antioxidant, which means it helps mend broken cells.

"The damage can be started by oxygen. The thing is that people need oxygen in their blood to help give them energy, but oxygen actually corrodes cells a bit. It's OK that it does that, because the body can make new cells, and the ones oxygen burns out might not be working so well any more anyway. But some damaged ones flow around the system looking for parts of other cells they can snaffle to mend themselves. Yeah, I know it sounds weird, but I think that's kind of how it works. They flow around the system till they manage to take certain parts from other cells and mend themselves, but then those cells are broken, and they themselves flow around the system looking for parts to mend themselves with, and snaffle bits from other cells to mend themselves, but then those cells are damaged and do the same.

"The broken cells are called free radicals. If too much of that kind of thing goes on, people get to be more vulnerable to diseases like heart disease and maybe Alzheimer's disease and some cancers. But the thing is that certain vitamins, like vitamin E and vitamin C, and also beta carotene, contain the things the broken cells are looking for to mend themselves, so they let the cells have the ones they've got, so the cells don't snaffle the parts from other cells.

"Beta carotene, which is the plant form of vitamin A, and the other antioxidant vitamins, are found in colourful vegetables and fruits. Beta carotene's found in ones like broccoli, carrots, green peppers, spinach, cantaloupe and water melon, mangos, peaches and nectarines, tomatoes and tangerines.

"Vitamin C's in lots of fruits and vegetables including cauliflower, Brussels sprouts, red, green and yellow sweet peppers, cabbage, cantaloupe and honeydew melons, strawberries, oranges, tomatoes and mangos.

"Vitamin E's found in red peppers, carrots, broccoli, spinach, mangos, and some other fruits and vegetables, and also nuts and sunflower seeds.

"So when you eat things like that, you're helping some of your cells mend themselves when they get damaged in certain ways, without them damaging other cells by snaffling bits off them to mend themselves with.

"Anyway, talking of nuts, they're another thing a lot of people are allergic to. So anyone giving them up could get their vitamin E from some of those other things. Nuts also contain other vitamins and minerals, including zinc, which is essential for the body to keep its DNA in good working order and to reproduce it in new cells. So it's essential to help children actually grow. It's also essential to help the immune system work well. Apparently even a mild zinc deficiency makes the body more prone to infection. And it helps the taste buds and sense of smell work well. It's found in a lot of animal products including milk and cheese, as well as things like green peas, spinach, chickpeas, baked beans, sesame and pumpkin seeds.

"Nuts also contain copper, which people need in small amounts because it also helps protect the body from damage caused by the broken cells, and also helps the bones and connective tissue grow healthily, and also helps the body absorb nutrition from food. It helps it release iron from its stores to make healthy red blood cells. But copper's found in quite a lot of other foods besides nuts, including lentils, green beans, garlic, tomatoes, seeds like pumpkin and sesame seeds, dates and other things. So if you've got some of those in your diet, you'll be allright for copper if you give up nuts."

The Students Joke Around For a While

Then one student said, "How do you know all this stuff? You sound like a health nut! You do realise, don't you, that you could eat really healthily for years and years, denying yourself all the fatty sugary foods you love, only to one day be knocked down by a busker?"

"Did you say knocked down by a busker?" asked the student who'd been talking about healthy food.

Another one grinned and joked, "Yes, that would be bad luck, wouldn't it! Yeah, maybe just as they say really high notes can shatter glass, maybe you'll be walking past an ex-opera singer who's decided to take up busking to earn a bit of money one day, and she'll sing higher notes than she's ever sung before, and maybe you and a lot of other people walking past will be feeling delicate - say it's winter and you've all had the flu - and when she sings those notes, you might all suddenly shatter into millions of pieces like glass and fly up into the air and then come down in a heap in front of her."

"I don't think anyone would fancy throwing her any more money when they walked by and saw a heap of people smithereens in front of her," said one student with a chuckle.

Another student grinned and said, "I don't actually suppose she would fancy singing any more after they came down in front of her!"

One student said, "Hey wouldn't it be funny if she somehow managed not to shatter any people with her singing, but someone in a shop behind where she was found lots of recordings on the Internet of smashing glass, like chandeliers falling down and breaking, and windows and glasses and all kinds of things crashing to the floor and shattering, and every time she began to sing, they put the recordings on at top volume, so it sounded as if her voice was making loads of glass things in the shop behind her crash to the floor and smash!"

"She might get worried herself and sing lower from then on, or even go into the shop and apologise!" said one student.

"Or more likely run away as fast as she could!" said another student with a grin.

One said, "Hey imagine if a busker was playing a guitar, and someone out of sight had a recording of someone playing a few jangly notes on a guitar and then a string snapping and them yelling 'Ouch!' because it hurt their finger, and they kept playing the recording every twenty seconds or so. It would sound to passers-by as if the busker kept snapping his guitar strings and yelling ouch, but then carrying on valiantly as if nothing had happened!"

The students laughed, and one said, "If some passers-by stayed in the vicinity for a while, they'd start wondering just how many strings this man's guitar had!"

Another one said, "Or maybe it could be a recording of a rubber band. I used to play rubber bands when I was little. I used to stretch them on a couple of my fingers and then twang them with another finger, and they played different notes according to how much they were stretched. Just imagine if someone made a recording of tunes being played by people twanging rubber bands, and they somehow amplified it a lot and played it whenever a busker started playing his guitar; it would be the guitar and rubber band duet. But imagine if it was made to sound as if the rubber bands kept snapping and there was someone shouting 'ouch' every time one did on the recording! And imagine if they shouted ouch in a higher or deeper voice that matched the note the rubber band was playing when it sounded as if it snapped, so you'd have the person shouting ouch at all different pitches! Low, then high, then low again maybe, and it might carry on like that for hours!"

"I'm sure the busker playing the guitar would get fed up and move long before it could go on that long!" said another student with a chuckle.

"But what if the person with the rubber-band-and-ouch recording kept following him wherever he went!" said one student with a grin. "Imagine if he somehow managed to follow him without being seen all day!"

The students laughed, and one said with a giggle, "Gosh, wouldn't that be awful for the busker!"