Can your toast give you cancer?
There has been a concern about cooked starchy foods producing the potentially harmful chemical acrylamide. Acrylamide is naturally found in starchy foods and is formed during cooking as part of the Maillard reaction, which turns food a lovely golden brown colour.
Acrylamide formation chiefly occurs when foods with a high starch content such as potatoes, root vegetables and bread, are cooked at temperatures over 120°C during frying, roasting or baking.
A new consumer campaign in the UK on reducing acrylamide exposure is based on long-standing evidence from animal studies linking the chemical to cancer. But so far in humans, the same link has yet to be seen.
Still, in 2005, a joint FAO/WHO Expert Committee on Food Additives concluded that there is a possibility of human health concerns with acrylamide even with our generally low intake.
The most surprising thing about the acrylamide warnings is that there is nothing new in them that health and food regulatory bodies in Australia, the United States and Europe have not raised before. The new angle was the stronger wording of the risk and clearly defined advice on reducing exposure.
The research findings
The cancer fears from acrylamide come almost exclusively from rat studies. There is no firm research linking acrylamide found naturally in food to cancer in humans. But the possibility cannot be excluded.
A recent systematic review and meta-analysis concluded that dietary acrylamide is not related to the risk of most common cancers in humans so if there is a risk, it’s likely small.
The American Cancer Society lists acrylamide as a ‘probable carcinogen’. A list of things in our environment that are probable carcinogens would be so long that it would make a person retreat into a bunker for fear. Cancer risk is all about appreciating the big players are the ones you can control. Smoking, alcohol, physical inactivity, too much sun, obesity and a poor diet are at the top of the list.
Putting the advice into practice
While toast contains less acrylamide than potato chips and fries, toasted white bread is one of the main food sources of acrylamide, so it is the food that has attracted headlines. Work done by Food Standards Australia and New Zealand estimated dietary acrylamide exposure of Australians is in the range considered to be of possible concern to human health so it is certainly worth considering how someone could lower their exposure.
Here are the key tips for reducing acrylamide exposure:
- Aim for a yellow or golden brown colour when frying, roasting or baking food.
- Toast bread or other foods to the lightest colour acceptable to your taste, noting that the crust will have higher levels of acrylamide.
- Avoid keeping potatoes in the fridge before cooking them, as this can further increase acrylamide levels.
- Soak potatoes in water for 15-30 minutes, or blanch in boiling water before frying or roasting. This reduces the components that promote acrylamide formation.
- Follow cooking instructions on food packages to avoid overcooking.
Last Reviewed: 19/12/2019
© Norman Swan Medical Communications.
Food Standards Agency United Kingdom. Acrylamide https://www.food.gov.uk/science/acrylamide-0 Food Standards Australia and New Zealand. Acrylamide and food. http://www.foodstandards.gov.au/consumer/chemicals/acrylamide