Acrylamide in the chips

Pretty much everything that gives us pleasure in eating is due to the Maillard reaction: the browning on chips, roast potatoes, fresh-baked bread crust, steaks, hamburgers, roasted coffee, maple syrup, dried milk, chocolate, malted barley for whiskey and beer.  The rest of the food we eat: porridge, broccolli, boiled spuds is just the stodge and fibre: necessary but not sufficient for a diet that pleases. Maillarding occurs when the amino acid constituents of proteins react at high temperature with 'reducing' sugars like glucose and fructose.  It's not possible to write a chemical equation because, although the inputs are limited the outputs are many and varied: a cocktail of tasty chemicals that are 'mostly harmless'.

One of them is likely to be acrylamide [R] or prop-2-enamide, which was the focus of a report in RTE wireless last night.  I missed the beginning but suppose that some food-safety report must have been published warning us about the dangers of consuming this stuff.  Acrylamide in food has an interesting and quite recent history.  It is used in a variety of industrial-chemical processes and in 2002, some Swedish scientists were called in to assess the toxicity of acrylamide dust in a factory where there was a lot of it about. They cast about for a control population that was unexposed, to establish a base-line and were surprised the find that their controls were also exposed to low doses of the chemical under investigation. The source was tracked down to Swedish crisp-bread but also to the long list of tasty chow mentioned above. At around the same time, it was found that feeding large amounts to lab rats resulted in tumours in every tissue looked at.  But cyclamates and saccharine have also at one time or another been shown to cause cancer in lab rats and accordingly been banned in some countries.  Saccharine used to carry a health warning the US until proper science showed that lab rats were, in this case, a poor model for human metabolism.  Their urine has much higher levels of pH, calcium and protein and these produced crystals that damaged the lining of the bladder to precipitate the onset of cancer.

But acrylamide is not an artificial additive amenable to legislation, it is a natural by-product of baking, roasting and frying and, as a part of the Maillard reaction, may be a desirable addition to cooked food. It turns out that the levels of acrylamide fed to the rats to induce cancer was 900x greater than a reasonable person is likely to get in the diet. A number of epidemiological studies have been carried out to track the impact of a diet high in acrylamide on long-term health.  A few of these studies have shown statistically significant association, while others have not.  This is typical of associations that are so small that they require thousands of cases and thousands of controls to detect any difference. Science has an almost unavoidable publication bias - it's hard to get negative results published while positive results in a field (like diet and human health) that everybody thinks they understand will mobilise your University's publicity department to issue a press release.  This will remove all the equivocation and qualification of your findings and the Daily Mail will reduce the press release to a catchy headline and two paragraphs of excited extrapolation from your results.

The Food Safety Authority of Ireland FSAI will shortly issue a warning advising us to eat soggy chips and discarding the crusts of bread.  If you want to live forever on a diet of cabbage and porridge, you're welcome.