French fries and potato chips may be doing more than just clogging our arteries and padding our guts. The first peer-reviewed study of acrylamide levels in foods suggests the suspected carcinogen forms in dangerous levels during the cooking of potatoes.

The findings are reported in the August 14 print issue of Journal of Agricultural and Food Chemistry, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society. They were the basis for widely publicized announcements by the Swedish National Food Administration and other European food administrations this spring.

The study reports that fried, oven-baked and deep-fried potato and cereal products contain high levels of acrylamide. Researchers at Stockholm University summarized evidence of acrylamide's presence in foods and performed a detailed analysis of acrylamide during heating.

Protein-rich foods, such as beef and chicken, produced only moderate levels of acrylamide when heated. Carbohydrate-rich foods, however, had high levels, with potato chips and French fries at the top of the list. Any item containing potato produced significant acrylamide upon heating in microwaves or conventional ovens. The study also found that more acrylamide forms as food is heated to higher temperatures.

Boiling at 100 degrees Celsius appears to be the only safe cooking method. In potato-based foods, even cooking at a moderate temperature of 120 degrees Celsius began the process of acrylamide formation.

Scientists originally thought the main exposure to acrylamide was through tobacco smoke; early studies suggested it formed during incomplete combustion of organic matter. When researchers found unusually high levels of acrylamide in Swedish subjects who were non-smokers and not exposed to other typical sources, the Stockholm group formed their heated-food hypothesis.

In an earlier study published in an American Chemical Society journal, rats were fed fried animal feed for one or two months. The rats exhibited a higher level of acrylamide than a control group -- an increase similar in magnitude to the high levels observed in non-smoking humans.

After learning of the Stockholm University research, the Swedish government began testing acrylamide levels early this year and confirmed that many starch-rich foods contained high levels. This led to its announcement in April.

The Stockholm University study is the first to go through the peer-review process, and it bolsters the results made public by the Swedish National Food Administration and others. It also gives detailed information about the analytical methods used to measure acrylamide levels and the evidence for the identification of acrylamide in heated foods.

Journal of Agricultural and Food Chemistry August 14, 2002

Dr. Mercola's Comments:

How can anyone expect to be in good, much less excellent, health if they routinely eat highly processed carbohydrates? Potatoes are bad enough when consumed in their raw state, as their simple sugars are rapidly converted to glucose that raises insulin levels and can devastate your health. But when they are cooked in trans-fat at high temperatures, all sorts of interesting and very unpleasant things occur. That acrylamide develops in such foods makes perfect sense and should have been anticipated. But I am sure there are many more surprises produced in these foods that seriously damage health and lead to the development of chronic degenerative disease. 90% of the money Americans spend on food goes toward processed foods. This is one of the major physical reasons for most human health problems. When I consult with new patients, one of my primary roles is to guide them toward consuming more unprocessed foods. Ideally, over 50% and up to 90% of the human diet should be uncooked or raw food. My diet is probably about 80% raw food when I am at home. The above story is not getting much exposure in the U.S. It has taken a hold in Europe, however. And I was recently contacted by 60 Minutes Australia, who want to interview me for a story they're producing on this topic (I will post when they plan on airing the story.) Related Articles: U.S. Junk Food Intake Worsening Link Seen Between Cooking and Cancer More on Cancer Chemical in Cooked Food More Reports Confirm Carcinogen in Snack Chips and French Fries The Dangers of Over-Cooking Your Food