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Student Questions: Food Woo and Iron Man at the Airport

Donate Skeptoid answers another round of questions sent in by students all around the world.  

by Brian Dunning

Filed under Feedback & Questions

Skeptoid Podcast #319
July 17, 2012
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Student Questions: Food Woo and Iron Man at the Airport

Wherever I go, speaking to student audiences, food woo continues to be the most prevalent theme that I run into. By food woo, I mean pseudoscientific beliefs about food. Some food is incredibly bad for you but nobody has noticed yet, or some food incredibly brings miraculous health but the industry covers it up. So we're going to start this round of student questions with a few such beliefs. They all follow this same basic theme: Will this particular food, diet, or eating habit bring incredible health or incredible detriment, like I've heard on the Internet? Sometimes claims that sound astonishing are true, but more often than not, they're just urban legends. Here's a perfect example to start with, an eating habit that your mother probably always warned you about:

Hi Brian, my name is Kris and I'm a Ph.D. student at the University of New England in New South Wales, Australia. I rarely eat breakfast until mid morning, but people around me often tell me "breakfast is the most important meal of the day" and otherwise suggest that I am sabotaging my own potential by not having a large breakfast. I have found conflicting reports online with few satisfactory sources on the subject. Can you find me a science-based answer to this issue? Thanks.

One of the reasons there are no miracle weight-loss products on the market that actually work is that the mechanisms governing your body's hunger cravings are really, really complicated and still not even fully understood. These mechanisms probably also differ from person to person. But there is still a lot that we do know. For one thing, the connection between your stomach and your muscles is not direct; it's not like you eat something and immediately use the energy from that food. Your muscles are kept supplied by your blood, and your blood is kept supplied by a number of storage systems and regulated by different systems as well. However, every so often your brain tells you that it's time to eat, and it might hit you with any number of biochemical signals that make you feel weak, tired, or hungry. It's a complicated system, but as long as you get enough food in you every day, it's going to continue to work fine.

How you feel throughout that day is another matter. Some people get those signals from the brain, those hunger cravings or periods or weakness or light-headedness, sooner or more often than other people. Some people avoid them best by eating throughout the day, and some people don't really get them at all and are fine with eating a single big meal. It's really an individual thing. Short answer: If you don't feel you need breakfast, there's no reason for you to eat it; so long as you get those calories eventually at some point in the day.

Hi Brian, I'm from the University of Florida and my question is about the medical benefits of papaya. A friend of mine who is from China recently told me that Chinese women think papaya will make their breasts grow bigger, so they eat papaya to make that happen. Is that at all factually based, and if not, do you know why it is so prevalent in Chinese culture? Thanks.

If true, papaya would be the most in-demand product of all time. It isn't, which should suggest that not much proper investigation has found any merit to this belief.

Breast size, like most aspects of the human body, is determined by genetics. Most women's breasts will enlarge if they put on weight, and papayas are high in sugar and calories, and are a great way to put on weight. So they're a fine way to grow your breasts, but only if you also want to grow the rest of yourself at the same time.

Hello Brian Dunning, this is James. I have been a student at Fox Valley Technical College working to a degree in IT computer support specialist. I was wondering if natural sugar is so much better for you than artificial sugar. Meaning apples oranges and other stuff, and artificial sugars meaning candy, ice cream, and soda. Is this true or not?

James, a molecule is a molecule. Sugar is sucrose, a disaccharide of glucose and fructose. That molecule is absolutely identical, down to the last quark, whether it came from sugar cane or from anywhere else, and whether it's found in an apple or it's found in ice cream.

But what people really mean when they say "artificial sugar" is high fructose corn syrup, which we've discussed in depth on a previous Skeptoid episode. HFCS consists of those same two monosaccharides, glucose and fructose, yet they're not chemically bound together. So it's still a sugar, but it allows the food companies the ability to alter the proportion between glucose and fructose in order to tweak the sweetness up or down. When you eat sugar, the first thing your digestive system does is break that bond, so whether you eat sugar or HFCS makes no difference once it's in your body. The media loves to report research showing some difference in the way your body metabolizes the two, as if alarm bells are ringing and telling us that HFCS is more harmful; but the overwhelming majority of research shows there is no significant difference to your body, just as basic chemistry predicts.

The best advice is to avoid both of them, because any added sweetener is just extra calories that your body doesn't need, and will just make you fat.

OK, enough with the food woo. Let's move onto some other subject areas, beginning with brain-training video games, also making incredible-sounding claims:

Hi Brian, this is Julian, student at University of Hildesheim, Germany, and I'd like to know: What is the real effectiveness of those brain training programs you can get on the Internet or on gaming consoles? Some companies claim to be working with neuroscientists and to base their work on actual scientific findings, but I wonder: Can you really enhance your memory and concentration just by playing a couple of simple games?

We have a pretty definitive answer for this one at the present time: No. The good doctors and neurologists over at the Science-Based Medicine blog talk about this subject pretty often, and they've ably summarized the best research to date. No one study gives a conclusive answer, of course, but among the largest and best of these placed almost 5,000 subjects into three groups (including a control), and their skills were tested after six weeks of using brain training games intended to improve reasoning, planning, problem solving, memory, attention, visuospatial processing, and math. The result? There was no statistically significant difference between the groups who played the games and the control subjects who did not. Save your money unless and until the data supports the vendors' claims.

Hey Brian. I'm Will, and I live in Doha, Qatar. I recently heard a claim that there are plants in the amazon rainforest that can cure cancer. Is this true, to any extent? Thanks.

Yes and no. No, there has never been any good evidence that a single cure for any or all cancers has ever been found in any particular plant or compound, the way it's depicted in Hollywood as when Sean Connery's character found one in Medicine Man. But yes, there are undoubtedly many more useful drugs still to be found in the wild.

What many people don't realize is that compounds found in nature — from the jungle, the ocean, and everywhere else — have always been, and continue to be, the main source for most of our pharmaceutical discoveries. Some people like to think there is an "us against them" mentality, where the products of big pharmaceutical companies compete against nature's herbs. In fact, they are one and the same thing. Every pharmaceutical company in the world has researchers everywhere, searching and testing and studying nature (just like Sean Connery's character), and hoping to find the next discovery.

Cancers represent such a huge and diverse category of diseases that it's very unlikely any one compound will treat all of them, Amazon rainforest or not; but that's not going to stop the molecular biologists from pointing their microscopes at the jungle.

Hi Brian. My name is Niklas Westerberg and I'm a medical student at the university of Oslo in Norway. In a recent lecture on hemochromatosis we were told about this person being stopped at an airport in the security control because he had so much iron in his body. To me this sounds like an urban legend. Could this really be true?

This is very unlikely. Most of these stories seem to reference an old medical case where a guy nicknamed "the Iron Man" supposedly set off a metal detector and couldn't get on a plane, but as far as finding well-sourced modern cases where specific names and dates are given, I came up empty. Nevertheless, this story is repeated on many web pages and throughout the literature.

Hemochromatosis is a real medical condition, usually inherited, but it can also be acquired. As many as 1 in 9 men in northern Europe, where it's most common, have this gene. The condition is usually detected sometime in middle age, when the iron levels have built up high enough to start causing problems. The worst cases can have 10 times the normal amount of iron in their bodies; possibly as much as 40 or 50 grams. The treatment is simple phlebotomy, draining blood from the patient, a bit at a time, until the iron levels are normal.

Airport metal detectors are basically magnetometers. They are triggered by metal inducing an electromagnetic current. For induction to happen, you have to have a continuous piece of metal. Conversely, the iron atoms in our hemoglobin are chemically bound within large organic ring molecules called hemes. There is no induction-capable metal in your blood. This is also why blood is not magnetic, just as rust is not magnetic. An element's properties are largely determined by its chemical state, and iron-rich hemoglobin has completely different properties than simple iron.

So who "the Iron Man" was, and whether he actually set off a metal detector, and what caused it to go off, we don't know. But we can be pretty sure that the cause was not hemochromatosis, no matter how many web pages say that it was.

By Brian Dunning

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Cite this article:
Dunning, B. "Student Questions: Food Woo and Iron Man at the Airport." Skeptoid Podcast. Skeptoid Media, 17 Jul 2012. Web. 27 May 2024. <>


References & Further Reading

Editors. "Magnetism." ThinkQuest. Oracle Education Foundation, 17 Sep. 2000. Web. 8 Jul. 2012. <>

Melanson K.J., Zukley L., Lowndes J., Nguyen V., Angelopoulos T.J., Rippe J.M. "Effects of high-fructose corn syrup and sucrose consumption on circulating glucose, insulin, leptin, and ghrelin and on appetite in normal-weight women." Nutrition. 3 Mar. 2007, Volume 23, Issue 2: 103-112.

NIH. "Hemochromatosis." PubMed Health. US National Library of Medicine, 4 Mar. 2012. Web. 8 Jul. 2012. <>

Novella, S. "Brain-Training Products Useless in Study." Science-Based Medicine. Science-Based Medicine, 21 Apr. 2010. Web. 6 Jul. 2012. <>

Sizer, F., Whitney, E. Nutrition: Concepts and Controversies. Belmont, CA: Thomson Higher Education, 2007. 105.

Tyson, J. "How Metal Detectors Work." HowStuffWorks. Discovery Communications, 1 Feb. 2009. Web. 8 Jul. 2012. <>


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