When I mention that I’m from South Korea, the most common response is, “Oh my god I absolutely love Korean BBQ!” My culture evokes an image of rowdy customers in a smoky restaurant where marinated beef sizzles on a table decorated with colorful and exotic foods, topped off with a bowl of sticky white rice. And it is perhaps because of South Korea’s meat-eating culture that I am one of very few South Korean vegetarians. To be completely honest, there are moments when I miss eating meat. On paper, tofu and eggs might be able to keep protein deficiency at bay, but they won’t be able to fully replace a juicy chicken-and-pesto panini.
The recent World Health Organization report, however, is one of many reasons that I continue to exclude once-live animals from my diet. On October 26, 2015, the International Agency for Research on Cancer presented Press Release No. 240, in which they classified the consumption of processed meat as Group 1, meaning that it is carcinogenic to humans. The consumption of red meat was categorized in the less dangerous Group 2A, meaning that it is probably carcinogenic to humans. Processed meats are defined as all meat that has been transformed by salting, curing, fermenting, smoking, or other processes that are meant to enhance flavor or improve preservation. And according to Press Release No. 240, each 50-gram portion of this meat eaten daily increases an individual’s risk of colorectal cancer by a sturdy 18%. The short report clearly indicates that red meat is an unhealthy option.
It comes as little surprise, then, that in many countries that value red meat, including America, this release has been met with controversy. The comments range from calm readers imploring others to exercise moderation in their diets to vehement vegans actively promoting their dairy-free lifestyles in the name of animals’ rights, and now health.
Whether or not you opted for bacon at today’s breakfast, let’s examine the science behind these discoveries. Statistically, colorectal cancer is the third most common non-skin cancer in the United States; this year, 133,000 patients will be diagnosed, the majority over age 50. If red meat is a carcinogen, simply changing diets moderately would enable many people, most of whom are in the latter halves of their lives, to avoid expensive treatments and suffering.
Studies show that breathing in the products of wood fires or car engines, which include polycyclic aromatic hydrocarbons (PAHs), increases the risk of cancer in humans. In its metabolically active form, PAHs can bind to targets in an individual’s DNA where it mutates the DNA and creates tumors. While PAHs are introduced environmentally by wood burning and car exhaust, the processing of red meats leads to the formation of these same carcinogenic molecules and introduces them to people through their diets. PAHs can also be introduced to meats when grilling or boiling over a direct flame; the fat dropping on the hot fire produces PAHs that rise with the flames and adhere to the surface of food. The more intense the heat, the more PAHs are present in the cooked meat, and the more PAHs are present, the more DNA is mutated.
Another class of carcinogenic molecules are called heterocyclic aromatic amines (HAAs). They were first found in cooked foods in 1977. Since then, more than twenty HAAs have been identified as potential threats to human health. Their formation is dependent on the type of meat and the conditions of cooking: temperature, duration, and flame. The concentrations of HAAs can vary by more than 100 fold, but the trend shows that prolonged cooking time and high temperatures produce the highest quantities of HAAs. The ability of HAAs to mutate your DNA is due to its chemical structure, which allows the molecule to undergo a process called N-oxidation to form a reactive nitrenium ion. This form is the intermediate in the creation of an HAA-DNA adduct, which creates lesions in the DNA of slowly dividing tissues.
The risk of cancer onset posed by the consumption of processed meat or red meats is nowhere near as high as that by smoking or alcohol consumption. However, studies in England and Germany have shown that vegetarians are about 40% less likely to develop cancers in general compared to meat eaters. To those who have a diet that relies on meat, I encourage you to try vegetarianism for a while. While many argue against vegetarianism by saying that one person’s dietary restriction may not have a profound effect on the environment or in shaping governmental laws that dictate the American agricultural industry, it certainly will have a beneficial impact on your health.
Claire Kim is a sophomore in Timothy Dwight College. Contact her at firstname.lastname@example.org.
(Featured image from here.)