Spend enough time clicking through science headines over the last 50 years, and you'll begin to suspect that everything causes cancer. But one particular notion has been in heavy circulation recently -- the idea that burnt and overcooked foods contain dangerous carcinogens. Is it true?
The answer is ... kinda-sorta. We realize this leaves something to be desired in regard to ambiguity, but that's science for you. Trace Dominguez has the details in today's DNews special report.
In 2002, researchers at Stockholm University found that starchy foods, when heated to 120 degrees Celsius, created a kind of byproduct chemical called acrylamide. The chemical is produced by a reaction between asparagine, a non-essential amino acid, and certain sugars like fructose. Significantly, the chemical is not found in unheated foods.
RELATED: Are Long-Term Vegetarians More Likely to Get Cancer Than Meat Eaters?
Acrylamide, alas, is a known carcinogen. (It's also found in cigarette smoke.) In studies where acrylamide was given to lab rats in their drinking water, it caused tumors in the lungs, thyroid, adrenal glands and testicles. It also seemingly caused mutations in mouse sperm DNA. So that's not great.
In humans, however, the hard science is a little less scary. Acrylamide is known to irritate the skin and scientists believe it might be a tumor initiator. It's officially classified as a Group 2A carcinogen by the International Agency for Research on Cancer, meaning it probably causes cancer in humans, but not conclusively. Bear in mind, too, that the acrylamide doses being fed to the lab rodents was 10,000 times higher than any amount you can get from burnt food.
There's more bad news, though. Aside from starchy foods, research has found that meat cooked at high temperatures -- pan-fried or over an open flame -- also produces dangerous chemicals. Heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs) are mutagenic chemicals, meaning they cause changes in DNA and may increase the risk of cancer. These chemicals are even present in the smoke coming off the cooked meats.
It's scary all right. But, as we say, so are 90 percent of the science headlines concerning cancer. Remember, the studies are just pointing out these chemicals exist in the world, and cause cancers sometimes. Although there is a correlation between eating well-cooked meat -- and starchy foods cooked at high temperatures -- and certain types of cancers, it is nowhere near as clear as the link between, say, cigarettes and lung cancer, or sun exposure and skin cancer.
-- Glenn McDonald
National Library Of Medicine: Heritable Translocations Induced By Dermal Exposure Of Male Mice To Acrylamide
National Cancer Institute: Chemicals In Meat Cooked At High Temperatures And Cancer Risk
National Library Of Medicine: Amended Final Report On The Safety Assessment Of Polyacrylamide And Acrylamide Residues In Cosmetics