Complexities in Food Safety – The Maillard Reaction

Posted on November 4, 2017

We often think of food safety through the lens of sourcing. If we buy healthy items from reputable providers who follow best practices, the food will be safe to eat.  For the most part this is true, but a growing body of research involving the Maillard reaction is showing that the way we prepare food can create carcinogens and toxins. The Maillard reaction is a complex chemical process responsible for food “browning” when exposed to heat. With multiple reagents and even more products, it is poorly understood and is a hot bed for current research. In the past two decades we have discovered surprising carcinogens in food that were not present before cooking. This post will examine the broad strokes of the chemistry of carcinogens in meat and how they form.

In 2015 the internet exploded when the World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) classified red meat products as a carcinogen. Highly processed meat, pan fried meat, and meat cooked over open fire were the worst contenders. What’s interesting about it is where the carcinogens come from. Certainly some of the come from the production process of things like hot dogs, but even carcinogen free raw meat became carcinogenic after cooking. The most likely chemical suspects are heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs), although there are likely other chemicals involved. HCAs develop when amino acids, reducing sugars, and creatine are exposed to high temperatures. PAHs develop when juices from meat create open flames, colloquially known as flare ups. The smoke from these flare ups contain PAHs, which get reintroduced to the meat. Unlike other carcinogens found is food, these are a result of naturally occurring chemicals undergoing reactions in normal cooking environments. Carcinogenic pesticides can be removed or avoided, but we cannot remove amino acids from meat.  The question then becomes how dangerous are HCAs and PAHs and what we can do to mitigate their formation.

Since the WHO has already declared them carcinogenic, it is safe to say there is some risk associated with eating red and processed meat. However the exact risk is difficult to quantify. There are a plethora of factors involved in cancer risk, including genetics, age, field of work, stress levels, tobacco use, diet, and so on. Through rigorous analysis though the IARC found that eating 50 grams of processed meat products daily increased the lifetime risk of colorectal cancer from 5% to 6%. Although this is a statistically significant increase, it is not serious enough to recommend never eating these products. Even if that was recommended, people would never stop anyway. That leaves us with mitigation for protecting ourselves. The most obvious way to mitigate is to just eat less of it, but there may be other methods of mitigation as well. Perhaps there are chemical compounds that can be added to meat that interrupt that creation of HCAs and PAHs. New methodologies for processing and cooking meat may reduce their prevalence as well. More research is required to discover new best practices.