If you want to stay healthy, don’t brown your toast

Fluffy and crisp roast potatoes, chips and well-done toast could all cause cancer, public health chiefs have warned.

Starchy foods cooked at high temperatures or for a long time develop high levels of the chemical acrylamide, which scientists believe could lead to cancer in humans.

The Food Standards Agency (FSA) is starting a campaign today to encourage people to cut levels of the chemical in their diet, by only frying, roasting, baking, grilling or toasting to a light gold rather than dark brown colour.

The agency says that exposure levels are too high in all age groups in Britain, where 900 million meals accompanied by roast potatoes are consumed every year, according to industry figures, and about £400 million is spent on frozen chips.

The chemical is formed through a reaction between the natural amino acid asparagine and certain sugars present in the foods. It is found in breakfast cereals, chips, potato products, crackers and crisps, as well as root vegetables, including potatoes, sweet potatoes, beetroot, turnips, swedes and parsnips, once roasted and fried until dark brown or crispy. Boiling, steaming or microwaving them does not cause heightened levels of acrylamide.

As part of the new campaign, “Go for Gold”, people are advised to toast bread only until it is golden, not brown, and have roast potatoes slightly less brown and crispy.

Steve Wearne, director of policy at the Food Standards Agency, said: “We are not saying people should worry about the occasional meal . . . this is about managing risk over a lifetime.

“Anything you can do to reduce your exposure will reduce your lifetime risk. People might, for example, think ‘I like my roast potatoes crispy’, but they will just decide to have them less often.”

Other ways to reduce acrylamide include having chunky chips rather than fries or crinkle-cut chips, as the smaller surface area cuts down the level of acrylamide that can form. People should also not keep raw potatoes in the fridge, as this can lead to higher levels of acrylamide from a process known as “cold sweetening”, the agency said.

The public should also follow instructions on packaged foods, such as oven chips, rather than thinking that they can cook them more quickly by turning up the heat.

Gavin Shears, a senior policy adviser in contaminants at the FSA, said: “We are not expecting people to go out and radically change their diets, if they’re eating a healthy balanced diet. If you slightly overdo your roast potatoes on a Sunday, it’s not that you have to throw them away.”

Studies on mice have shown that high acrylamide levels can cause cancer and neurological damage. Studies on humans have proved inconclusive, but experts said that, because of the biological mechanisms involved, they believed the findings would translate to humans.

The US Environmental Protection Agency has said that acrylamide is “likely to be carcinogenic to humans”, and the International Agency for Research on Cancer, part of the World Health Organisation, describes it as a “probable human carcinogen”.