One of the most common summer customs is outdoor cooking: barbecue and or charring being one of the most highly practised. Like many modern practices, there is a degree of controversy surrounding outdoor cooking–especially with animal proteins (red/white meat, fish/seafood). Therefore, I want to walk you through the science, and offer some context.
So, what exactly is the issue with charring animal proteins? In short, due to their unique structure, when they are heated to temperatures above 212ºF (100ºC), they begin to form highly carcinogenic compounds known as (HAA). HAAs become even more potent at 572ºF (300ºC). So, the higher the temperature, the longer the cooking time, the higher the concentration of HAAs. Because they have been proven to work at the level of DNA, they have been classed as genotoxic. This means that they can create mutations, insertions, and deletions in our DNA, which is serious business we want to avoid. Further, it’s noteworthy that all methods for cooking animal proteins eventually create these rings. There are; however, proven ways to significantly reduce formation, which I will share.
Another set of compounds associated with high heat cooking are polycyclic aromatic hydrocarbons (PAH). They are formed when animal protein is blackened or charred on a metal surface, or when their fat and juices splash on to an open flame. This creates an incomplete combustion reaction, where white smoke is produced, or the flames rise directly on to the food. They then saturate the animal protein with PAHs. They are formed at temperatures of 392º F (200ºC) or higher, which poses another issue for the summer barbecue, seeing most animal proteins are cooked at 572ºF (300ºC) or higher. In many cases, certain cuts are cooked at 650ºF (343ºC) or higher. What’s so interesting is that these compounds only form when animal protein is cooked. If you were to eat these proteins raw, the compounds would not form; but, obviously other deleterious issues come into play with the consumption of raw animal protein (with the exception of sushi). This is why cooking these types of foods correctly is crucial, so what is an omnivore to do then? Well, although the science is a bit scary, simple steps can be taken to significantly reduce the formation of these carcinogens.
The first step to healthier barbecue is plants! Because they do not contain creatine amidst amino acids, HAAs are almost negligible when they’re cooked. Although some plant foods can produce PAHs (mostly processed gluten based grains and fats/oils), their concentration is much lower than their animal counter parts.
Plants are also packed with dense nutrient profiles that have been proven in the reduction of carcinogens, and the promotion of overall health. You want to choose veggies like kale, cabbage, collards, broccoli and cauliflower due to their anti-carcinogenic activity. Their high fibre content is a bonus too, seeing it can help the elimination of the toxins that form. There is also the option of reducing overall animal protein content by making some whole food veggie options, like mushroom and bean burgers, or a “carrot dog”. Ideally, 3/4s of your plate should be plant based (both raw and cooked) to ensure cellular protection. A perfect addition would be something fermented, like sauerkraut or organic yogurt, seeing it has been demonstrated that certain lacto-bacteria play a protective role when dealing with HAAs. Studies on Bifidobacterium longum (BB-536) suggest that it actually binds to HAAs and also works to prevent them from causing DNA damage in the colon and other organs. Therefore, it would be wise to supplement with this bacteria daily or at least on days charred animal proteins are consumed.
Herbs, such as rosemary and thyme have also been cited to reduce overall HAA content, along with garlic, ginger, and red chili pepper. These can either be rubbed directly on the animal protein or used in a marinade.
With marinades, the research points to wine and beer being the most effective at HAA reduction, when accompanied by one of the aforementioned herbs or spices. Interestingly, the darker the beer, the more protection offered. So, bring on the Guinness! Smarter summer grilling is all about anti-oxidant protection, so sip on scrumptious lemonade while prepping.
As mentioned, time and temperature affect the creation of HAAs and PAHs, so try to barbecue at lower temperatures until the item is safe to eat. Avoid well done, blackened or heavily charred parts. Use lean cuts, that are smaller, trimmed of fat, and try to keep them directly out of flames. Avoid pressing down on the cuts and flip more often to ensure even cooking. Avoid processed animal proteins, and aim for the highest quality grass fed, organic cuts, and wild caught seafood. Ensure that the grill is well cleaned upon use, opt for less chemically treated coals, and use a top rack that’s further away from direct flames. Lastly, do your own research on this subject and gather the information that is best for you as an individual. Although research based, this is still just an introductory starting point.
Khan, M. R., Busquets, R., Saurina, J., Hernández, S., & Puignou, L. (2013). Identification of Seafood as an Important Dietary Source of Heterocyclic Amines by Chemometry and Chromatography–Mass Spectrometry. Chemical Research in Toxicology,26(6), 1014-1022. doi:10.1021/tx4001682
Viegas, O., Amaro, L. F., Isabel M. P. L. V. O. Ferreira, & Pinho, O. (2012). Inhibitory Effect of Antioxidant-Rich Marinades on the Formation of Heterocyclic Aromatic Amines in Pan-Fried Beef. Journal of Agricultural and Food Chemistry, 60(24), 6235-6240. doi:10.1021/jf302227b
Viegas, O., Moreira, P. S., & Ferreira, I. M. (2015). Influence of beer marinades on the reduction of carcinogenic heterocyclic aromatic amines in charcoal-grilled pork meat. Food Additives & Contaminants: Part A, 1-9. doi:10.1080/19440049.2015.1010607
Zsivkovits M, Fekadu K, Sontag G, Nabinger U, Huber W, Kundi M, Chakraborty A, Foissy H, Knasmuller S. (2003). Prevention of heterocyclic amine-induced DNA damage in colon and liver of rats by different lactobacillus strains. Carcinogenesis, 24(12), 1913-1918. doi:10.1093/carcin/bgg167