Acrylamide on Toast – Carcinogen or Chemophobia?
All too often, public perception rather than actual scientific data sway policy over the use of certain chemicals. Aspartame, Bisphenol A and fructose have all taken a pasting in the last decade, and it now looks like acrylamide, a by-product of cooking starchy foods, is set to join this unhappy brethren. So with claims of carcinogenicity and a lawsuit on the way, is acrylamide a genuine problem or just another example of chemophobia?
Acrylamide is a small organic molecule that easily polymerises to form a very useful material, polyacrylamide, which finds use in both laboratory and industrial settings. Acrylamide itself was found to occur in foods in 2002, assumed to be a by-product of the Maillard reaction, and formed when the essential amino acid asparagine is reduced by sugars. The Maillard reaction (not to be confused with caramelisation) gives baked, grilled or fried food that lovely golden brown colour, and also forms a wide variety of compounds. The issue lies with acrylamide, which is considered toxic at very high levels and may also be carcinogenic.
Acrylamide has hit the headlines recently because of these carcinogenic concerns. The European Food Safety Authority produced a draft report showing acrylamide can cause cancer in animals, as well as an infographic with advice on how to reduce dietery acrylamide intake. Both the Daily Express and Daily Mail picked up on this advice, and, somewhat predictably, focussed on EU meddling with good old British foodstuffs; “Now EU bureaucrats tell us we can’t eat TOAST” shouts the Express. Despite the politicisation of the advice, both papers, to their credit, sought opinions from Cancer Research UK and British Food Standards Agency experts, who state that acrylamide carcinogenicity is unknown in humans, and exposure is thought to be low.
One of the biggest dietary sources of acrylamide is coffee, where the compound is produced during the roasting of coffee beans, and is thought to account for 20-40% of our acrylamide intake. Campaigners in California have sued major coffee retailers, with the Council for Education and Research on Toxics demanding all coffee products be labelled as carcinogenic at the point of sale under California’s strict proposition 65 act. Whilst acrylamide administered alone in large doses to mice and rats does induce cancer, there is no evidence that drinking coffee increases your overall chances of getting the disease: coffee is widely studied and no analyses have yet pointed to any increased risk.
So while it looks unlikely that every coffee in California will be sold with a warning label attached, should we still reduce our acrylamide intake? The British Food Standards Agency does not advise a change in diet, but recommends that burnt toast and overly browned chips should be avoided if possible. It has also found acrylamide levels in food are dropping, which is good news, but overcooking could increase acrylamide content. So, scientists everywhere can breathe a sigh of relief; you can still have that morning coffee or three, but the accompanying cigarette has to go. Acrylamide intake from smoking is at least three times higher than dietary exposure, as if you needed another reason to quit.