On the heels of the announcement that processed meat and red meat are carcinogenic, the bad news keeps rolling in for staples of many Western diets. A new study from the British Food Standards Agency, an analog to the United States' Food and Drug Administration, suggests that if you're toasting bread or frying or roasting some potatoes, it's best do so on the light side: Toast burnt to a crisp, browned fries, and potatoes roasted well-done could also give you cancer.
The FSA's study found that burnt toast and crispy fries are high in acrylamide, a chemical linked to cancer that is produced from a reaction between amino acids and the sugars and water in bread and potatoes when cooked above 120 degrees Celsius. The FSA tested lightly cooked and burnt-to-hell toast and potatoes from home-cooked meals at 50 households and compared the levels of acrylamide. The results were, well, dark.
Lightly cooked toast contained nine micrograms of acrylamide per kilogram, compared to 167 micrograms per kilogram for blackened toast. Heavily cooked fries contained 1052 micrograms of acrylamide per kilogram, more than 50 times that of lightly fried fries. And thoroughly roasted potatoes contained 490 micrograms, 80 times more than lightly roasted potatoes. Basically, the cook time and temperature determines the amount of acrylamide, with higher temperatures and longer cooking times leading to more acrylamide.
For some perspective, the amount of acrylamide that is permitted in Britain's water is 0.1 micrograms per liter.
"The risk assessment indicates that at the levels we are exposed to from food, acrylamide could be increasing the risk of cancer," said Guy Poppy, the FSA's chief scientific adviser.
Combined with the news about processed meats, the new announcement seems a bit like a war on breakfast. But Poppy says that they aren't advising that people stop eating potatoes and bread entirely; he suggests cooking potatoes to a light golden color and toasting bread as lightly as possible.
Potatoes, the FSA says, are best kept in a cupboard rather than a fridge, as colder temperatures can increase the sugar in a potato and thereby increase the amount of acrylamide when fried or roasted. Also, the larger the surface area, the more acrylamide, so when roasting potatoes, the FSA warns not to "fluff up" potatoes, a British term for shaking pre-boiled potatoes in a pan prior to roasting.
Also, if you were planning on cooking your potatoes using vegetable oil, such as corn or sunflower oil, better avoid those too, as they both can cause cancer as well.
But consequently, in a surprise silver lining that no one saw coming, scientists are now recommending cooking with lard and butter instead. So if you can't burn your bread and potatoes black, at least you can douse them with butter and only have to worry about the ensuing weight gain.