Burnt Toast Can Lead to Cancer, Experts Warn


Who hasn’t accidentally left bread in the toaster a little too long and burned it, only to scrape off the black parts and then proceed to eat it anyway? Now, experts reaffirm the long-standing belief that burnt toast may cause cancer.

Credit: Danielle Tarasiuk

On Monday, the Food Standards Agency in the UK launched a campaign to warn the public about the cancer risks linked to eating over-cooked starchy foods like burnt toast and over-roasted potatoes. The campaign is based on a 2002 study that linked high levels of a compound called acrylamide  — which is found in over-cooked starchy foods — to cancer in animals.

Acrylamide is what gives baked miniature potatoes, for example, that beautiful gold color. It is formed from simple sugars reacting with an amino acid called asparagine, when starchy foods are cooked at temperatures over 248 degrees Fahrenheit.  

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Asparagine is found naturally in starchy foods, but when these foods go from gold to brown and then eventually black, they produce higher levels of acrylamide that can increase cancer risk.

With the campaign, titled “Go for Gold,” the FSA hopes to increase awareness among the public. The research may not be new, but the agency is concerned most people remain unaware.

“Our research indicates that the majority of people are not aware that acrylamide exists, or that they might be able to reduce their personal intake,” Steve Wearne, director of policy at the Food Standards Agency, said in a statement. “We want our ‘Go for Gold’ campaign to highlight the issue so that consumers know how to make the small changes that may reduce their acrylamide consumption whilst still eating plenty of starchy carbohydrates and vegetables as recommended in government healthy eating advice.”

The campaign advised people to follow a few simple rules:

  • Go for Gold – Aim for a golden yellow color or lighter when frying, baking, toasting or roasting starchy foods like potatoes, root vegetables and bread.
  • Check the pack – Follow the cooking instructions carefully when frying or oven-heating packaged food products such as chips, roast potatoes and parsnips.
  • Eat a varied and balanced diet – While we can’t completely avoid risks like acrylamide in food, eating a healthy, balanced diet that includes basing meals on starchy carbohydrates and getting your 5 A Day will help reduce your risk of cancer.
  • Don’t keep raw potatoes in the fridge –  Storing raw potatoes in the fridge can increase overall acrylamide levels. Raw potatoes should ideally be stored in a dark, cool place at temperatures above 42°F.
Credit: Danielle Tarasiuk

Although there are no trials that link exposure to acrylamide and cancer in humans nor will there ever be, experts believe that the results of the trails on animals were strong and could be applicable to humans.

“No one will willingly eat acrylamide … (but) because it’s carcinogenic in animals, it would be carcinogenic in humans,” Donald Mottram, emeritus professor of food chemistry at the University of Reading in the UK, told CNN.

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For the last several years, the U.S. Food and Drug Administration also provided information on how to best reduce acrylamide in your diet.

“Generally speaking, acrylamide is more likely to accumulate when cooking is done for longer periods or at higher temperatures,” FDA chemist Lauren Robin said.

Robin added that boiling and steaming foods are typically the best option because they do not typically form acrylamide.