Dr Karl Kruszelnicki puts food under the microscope to unearth some facts that might surprise you
Have you ever wondered how good alcohol and chocolate really are for you, and is there really such a thing as a "fat" virus? Do artificial sweeteners help you lose weight, and is it true that Madonna once survived on a diet of popcorn alone? Read on to find out…
FALSE: While apples are an excellent wholefood and source of essential nutrients, an apple from 1940 contained three times as much iron as one of today's apples. This is due to the continuous growing of the same crops in the same soils, which removes the nutrients. This is why crop rotation is so important.
TRUE: Canadian researchers gave 100ml of ice-cream to 145 students, half of whom ate it in less than five seconds. The other half were told to eat less than 50ml in the first 30 seconds, then to "continue at their own pace". Twenty-seven per cent of the "accelerated eating" group reported ice-cream headaches, versus 13 per cent for the "cautious eating" group.
TRUE: Researchers in the US have discovered that an adenovirus called AD-36 causes obesity in both animals and humans. In general, human adenoviruses cause symptoms that are so minor and transient that most people don't even remember they were ever infected. However, it is still early days for this line of research and even if a virus infection can cause weight gain, you can probably manage the extra kilograms if you exercise and watch what you eat.
FALSE: While popcorn contains carbohydrate, water, fat, proteins and minerals, it is not possible to live off it. Popcorn doesn't contain enough niacin (vitamin B3), which is found in red meat, fish, poultry and green leafy vegetables and is essential for our survival. So, either she was eating some of these foods too, or she was popping vitamin tablets.
FALSE: (My daughter and I tried this experiment for one hour). When placed between two active mobile phones, after 60 minutes an uncooked egg will not warm up by even one-tenth of a degree.
FALSE: If you pinch your nose and close your eyes, you will still be able to distinguish between different foods by taste and texture and will be able to distinguish between, say, an apple (sweet, crisp), a raw potato (bland, crunchy), a raw onion (pungent, layered) and a carrot (sweet, crunchy).
TRUE: Scientists at the University of Western Ontario in Canada found when consumed, stirred martinis removed all but a microscopic 0.072 per cent of the oxidant hydrogen peroxide. Maybe James Bond was onto something…
FALSE: A study on rats at Purdue University in Indiana found artificial sweeteners break down the link between sweet tastes and calories, causing the rats to eat more and get fatter.
TRUE: If onions are chilled before cutting they release less of the irritant chemical, propanthial S-oxide, which makes us cry.
FALSE: Chocolate has been touted as having the ability to boost serotonin levels, but researchers from The Black Dog Institute in Sydney say there are three major problems with this theory. Firstly, your mood can change without there being any change in your serotonin levels. Secondly, serotonin levels increase only if the protein content of the food you are eating is less than two per cent. Chocolate contains about five per cent of protein.
Finally, when you eat chocolate emotionally – as "comfort food" – it is more likely to prolong your depression, instead of bringing it to an end. So the joy you receive from eating chocolate is short and sweet – the pleasure of anticipation, the taste and the "mouth feel."
TRUE: With one important exception – the Western refined-carbohydrate diet of flour and sugar. A study of Indigenous Australians who returned to a traditional bush diet for seven weeks found that even in this short time, they had both a decrease in weight and a reversal of metabolic abnormalities such as type 2 diabetes.
FALSE: While vodka contains no carbohydrates, it is high in energy. A 30ml shot contains 15ml of water (zero calories) and 15ml of alcohol (alcohol has 6.9 calories per millitre, so 15 x 6.9 = 103.5 calories). The belief that vodka has zero calories may have arisen around the time the Atkins diet was gaining popularity, along with the idea that a low-carb diet was healthy.
This is an edited extract from Brain Food by Dr Karl Kruszelnicki (Pan Macmillan, $32.99).