Burnt Toast - Is it Dangerous?

Irene Berman-Levine, PhD, RD
February 11, 2005

Burning my toast doesn't usually stop me from eating it. I love when some of it has a burnt taste. But should I eat it?

Burnt toast forms the same substance, acrylamide, which was highlighted in the news this year regarding a possible hazard in French fries and potato chips. When you expose many foods to high temperatures (baking, frying, canning) acrylamide can form. It's hard to define acrylamide other than it is a compound that forms naturally when heat hits foods that contain sugars and certain amino acids (the building blocks of protein). The main amino acid involved is asparagine.

This controversy began in April 2002, when a group of Swedish scientists detected trace levels of acrylamide in some baked and fried foods. Prior to this point no one had ever looked for acrylamide in food because it was not ever used as an ingredient and we did not realize it was in food. It's used in the production of polyacrylamide, which is used in water treatment, pulp and paper production, and mineral processing. According to the National Toxicology Program summary report, it is a known health hazard.¹

At this point the term acrylamide sounds scary but we have no evidence that the amount found in food is harmful to humans. There is concern, however, because several animal studies suggest it is harmful to reproductive and development processes in rats and mice. To make sure it does not hurt humans, scientists are studying it. They shared their findings in an Acrylamide Workshop at the Second Joint Institute for Food Safety and Applied Nutrition held in April 2004. This article summarizes some of the highlights of that meeting.²

The National Toxicology Program has convened a panel of experts to evaluate if acrylamide poses any risk to human reproduction and development. They evaluated 125 research papers. Because acrylamide research is so new, few results were available on humans. Those on mice and rats that showed problems were based on much higher levels of acrylamide then you would find in the American diet. Thus, they concluded that more research is needed, but there is little reason to be alarmed over acrylamide in our diets. But how do we know how much is in typical food intake?

The FDA has undertaken an analysis of acrylamide in the American food supply. They found that certain types of foods (potatoes, bread, cereal products) were more likely to have detectable amounts. The amount found in foods increased as the temperature during cooking and the length of cooking time increased.

For example, bread has only low levels but if you burn your toast, the burnt area has significantly higher amounts. Ditto for French fries. The levels of acrylamide increase as the cooking time and temperature increase. Thus, the degree of browning is one indicator of the levels of acrylamide.

The good news is that food storage and washing techniques are effective in reducing acrylamide formation. If you can prevent the formation of sugar (starch turns into sugar) it helps reduce acrylamide formation. In the case of potatoes, storage in a cool, dry, dark room and soaking/rinsing the sliced or cut potatoes in plain water reduces acrylamide levels in the final French fries.

Until more is known, FDA recommends consumers focus on those factors we know have a powerful influence on our health. These include eating a balanced diet, choosing a variety of foods that are low in trans-fats and saturated fat, and rich in high-fiber grains, fruit and vegetables. If you are concerned about acrylamide, here are some simple steps to reduce the amount in your diet.

Ways to reduce acrylamide levels in your food ³

• Avoid overcooking or using extremely high temperatures in cooking food. (note: undercooking some foods may result in foodborne illness!)
• If you fry foods, fry them to a light- rather than dark-brown.
• Scrape the darker crumbs off toast and other baked items before consuming.
• Store potatoes at room temperature in a dry location, then soak and rinse cut or sliced potatoes, before frying or baking. It's important to drain the potato slices before frying to prevent pan fires.
• Enjoy a moderate amount of a wide variety of foods to stay healthy.

Dr Irene is the author of "Nutrition Tidbits", a free newsletter which helps you understand the confusing world of nutrition and motivates you to choose healthy foods. You can sign up for the newsletter by clicking here.

Source

• I Berman-Levine PhD, RD. "Dr Irene's Nutrition Tidbits" Newsletter published by HealthandAge.com. Volume V Issue No 20, September 2004.

Footnotes
1. http://cerhr.niehs.nih.gov/news/acrylamide/AcrylMtgSum.pdf
2. http://cerhr.niehs.nih.gov/news/acrylamide/final_report.pdf
3. Food Insight, May/June 2004: http://ific.org/foodinsight

Related Links
WHO FAQs: Acrylamide in Food
Food Standards - Australia & NZ: Acrylamide in Food
Preserving, Transporting, and Storing Food

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