Originally published 8/7/2017
Despite cancer warnings, let’s face it. Untold millions of meat-lovers—and the restaurants that cater to them—continue to grill meat over high heat or open flames. As we wrote in the original blog, this causes the formation of carcinogens called heterocyclic aromatic amines (HAAs). HAAs have been implicated in increased cancer risk, especially colorectal cancer and prostate cancer, for over two decades. It’s not just red meat, either. We came across one study on chicken, and another on trout, showing that HAAs formed in the cooked flesh. The earlier blog offered three cooking modifications to lower the danger.
Well, for those who won’t give up the searing or charring that their taste buds demand, a 2019 paper[i] offers a possible strategy to diminish the contamination: probiotics! According to the authors, many probiotics are capable of “biodetoxification” by binding with the offending compounds, allowing the body to excrete them in waste. Sound easy? In fact, there are a number of variables involved, from which specific probiotics have this ability, to the chemical properties of binding. Interested readers (especially those who love biology and chemistry) can order a pdf of the full article for the price of a $65 steak dinner at a good chop house. Or, for a free copy, contact your local public library and ask the research librarian to obtain “Detoxification of Heterocyclic Aromatic Amines by Probiotic to Inhibit Medical Hazards”, and provide this document number: DOI : 10.2174/1389557519666190318102201. Love grilled meat? Added protection may be just a phone call away.
If you read the title and thought, “WHAT!? Is cooking meat linked to cancer?” you are not alone. Chances are, you were taught that meat is a valuable source of protein, and from early childhood on you learned that cooking meat can produce some incredibly yummy dishes. Today, most people know that some meats, especially lean meat and “white” meats, are healthier than others. If you are a health-conscious meat eater, you probably minimize red meat – or avoid it altogether in favor of poultry and fish. You may also have cut down on processed meats like hot dogs, and smoked meats such as bacon. If so, good for you!
However, when it comes to meat, it’s not just what you eat but how you cook it that may raise your chances of developing cancer, especially prostate cancer.
New evidence suggests that high temperature cooking, including grilling, broiling, barbecuing and pan-frying, changes the actual chemistry in beef, pork, chicken, fish and pretty much every other type of animal flesh. In addition, smoked meats also contain chemical changes. Here are the two most dangerous types of chemical compounds that form in response to high temperatures and smoking:
- When exposed to high heat, substances in the meat tissues combine to form HAAs (heterocyclic aromatic amines). These substances do not appear to exist in unheated meat.[ii] Ten years ago, the evidence that HAAs are carcinogenic (cancer-causing) was considered inconclusive.[iii] Today, animal studies and human population studies strongly suggest an association between consumption of HAAs and the development of cancerous tumors.[iv]
- PAHs (polycyclic aromatic hydrocarbons) also form during high heat cooking, but in addition they are found in smoked meats and tobacco smoke. Meat cooked on a grill over a flame is exposed to PAHs when fat drips on the flames and then spatters on the meat, as well as meat exposure to the smoke that occurs. These compounds are the result of incomplete burning of organic substances (wood, coal, oil, gas, etc.) so they are unfortunately abundant in our environment. Therefore, it is not only cooked meat consumption that gets them into our systems, but the air we breathe, products we put on our bodies, etc. They have known carcinogenic and toxic effects, which makes it that much more important that we reduce exposure to them by being careful about what we eat.
HAAs and PAHs do not in themselves cause cancer, but when we take them in through eating, enzymes in our bodies act upon them in a way that further alters them and gives them carcinogenic potential.
So, what can we do to reduce exposure to these toxic compounds? Studies have shown that their food levels can be lowered depending on how the meat is prepared. Here are three cooking suggestions:
- Reduce heat. Cooking at temperatures below 300°F limits the formation of HAAs. Grilling or frying over low heat may not produce that satisfying brown char that so many people find tasty, but if it enhances living cancer-free, it’s worth it.
- Reduce the cooking time. Well done meat is much higher in toxic compounds that get stored in our fat cells and eventually acted upon by enzymes to form carcinogens in our bodies. Also avoid cooking over an open flame, even for short times, since the smoke from drippings deposits PAHs on the meat.
- Consider marinating meat before cooking it. Certain marinades inhibit the formation of HAAs, especially those that contain antioxidants, herbs and spices, extracts of fruits and vegetables, garlic, grape seed extract, wine and other delicious ingredients. What you lose in charring, you might make up in how you treat the surface of the meat.
The wisdom of the ancient Greek physician Hippocrates sums up the importance of healthy eating: “Let food be thy medicine and medicine be thy food.”
[i] Khosravi-Darani K, Barzegar F, Baghdadi M. Detoxification of Heterocyclic Aromatic Amines by Probiotic to Inhibit Medical Hazards. Mini Rev Med Chem. 2019;19(15):1196-1203.
[ii] Gibis, M. Heterocyclic Aromatic Amines in Cooked Meat Products: Causes, Formation, Occurrence, and Risk Assessment. Com rev food sci safety. 2016;15:269–302.
[iii] Alaejos MS, González V, Afonso AM. Exposure to heterocyclic aromatic amines from the consumption of cooked red meat and its effect on human cancer risk: a review. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2008 Jan;25(1):2-24. Epub 2007 Oct 18.
[iv] Gibis, ibid.