In a recently released article, scientists studied “strongly heated carbohydrate-rich food” (i.e., French fries) and cancer risk. Frying potatoes produces a compound called acrylamide. Acrylamide has been theorized as a cancer-promoting compound. But more recent research has shown that high-acrylamide foods such as coffee do not, in fact, increase cancer risk.
The authors of this study took the investigation further, however. They measured the micronucleus frequency of human erythrocytes in peripheral blood (fMNs). This marker boils down to a measure of the damage to chromosomes, which are the collections of DNA inside cells (erythrocytes are red blood cells). Damage to DNA will directly increase cancer risk.
In the study, scientists compared two groups of people: those who ate either high- or low-heated food for a period of four days. The level of acrylamide was measured in the food consumed by both groups.
The researchers then measured the amount of fMNs (marker of DNA damage) in both groups, and compared it to the amount of fMNs experienced by mice who are exposed to a comparable amount of acrylamide. So scientists compared acrylamide intake to the production of DNA damage in both mice and humans, eating both low- and high-heated carbohydrates.
Here’s where things got interesting: Humans who ate heated carbohydrate-rich food experienced several hundred times higher fMNs than mice exposed to pure acrylamide. Thus, there are compounds other than acrylamide in foods like fried potatoes that damage DNA. The effect of these compounds is much more powerful than that of acrylamide. In fact, the authors suggest that our daily intake of fried carbohydrate-rich foods might be responsible for one-fifth of the rate of the total cancer risk.
In other words, this suggests that the risk of cancer is hundreds of times greater from French fries than what would have been estimated based just on acrylamide animal studies.
This simple study is a great reminder that animal studies are a good way to develop theories, but they don’t produce results that we can directly apply to humans without further research. In this case, the reality is much more severe than we would have thought based on animal data.
Deep-fried foods such as French fries and chicken nuggets are would obviously not have been produced by ancestral populations. This is especially true considering the hydrogenated oils usually used in restaurants. So it’s no surprise that these foods are not healthful. Avoiding deep-fried foods is a no-brainer with regards to health, especially when it comes to reducing cancer risk.