Eating overcooked starchy food is linked to cancer

Consumers are being warned about the dangers of overcooking toast, potatoes, and other starchy food because acrylamide, a chemical that is produced during cooking, has been linked to cancer.

The dangers of high levels of acrylamide have been recognised for about a decade, but in 2015 the European Food Safety Authority published a risk assessment saying that high levels of acrylamide in food potentially increased the risk of developing all types of cancer in all age groups.1

The Food Standards Agency is now launching its “Go for Gold” campaign, telling consumers that they should aim for a golden yellow colour or lighter when frying, baking, toasting, or roasting starchy foods like potatoes, root vegetables, and bread.

Boiling, steaming, and cooking food in the microwave do not have the same effect.

At a press briefing to launch the campaign scientists from the agency said that their advice was based on animal rather than human studies. Cath Mulholland, senior adviser on supplements, additives, and natural constituents at the agency, said, “In humans there is much less evidence but because the mechanism by which it causes cancer in animals is relevant in humans it’s sensible to assume it has that effect too.” She added, “It’s not a high level of risk but higher than is comfortable.”

The agency also emphasised the importance of following cooking instructions carefully, eating a varied and balanced diet, and not storing raw potatoes in the fridge because this leads to a process called cold sweetening, which increases levels of acrylamide.

Steve Wearne, director of policy at the agency, warned consumers not to cook food at higher temperatures but for shorter durations than recommended, as oven chips cooked at 225°C for 20 minutes contained nearly three times as much acrylamide as those cooked at 195°C for 24 minutes. He said that “variation and moderation” were the key messages. “Follow our advice and don’t have a too high a reliance on one type of food. People will make trade-offs. I like my roast potatoes but I won’t have them so often,” he said.

Guy Poppy, chief scientific adviser to the agency, said that the food industry had already begun to look at ways of reducing levels of the chemical. “Many potato growers are identifying potato varieties that generate less acrylamide. One of the very easy ways to do that would be general a genetically modified potato,” he said.