The Connection Between Meat and Colon Cancer

The Connection Between Meat and Colon Cancer

by Yenny (SU)

Colon/rectal cancer is the second leading cause of cancer-related deaths in the USA. According to the U.S. Centers for Disease Control and Prevention (CDC), around 136,717 people are diagnosed each year.

The World Health Organization (WHO) states that dietary habits are responsible for at least 30% percent of all cancers in developed countries and up to 20% in developing countries.

Opinions on the link between meat and colon cancer are contradictory and confusing. On the one hand we have news reports stating that red meat causes colon cancer, on the other, pro-meat debaters say the opposite.

International research shows significant reductions in cancer risk among those who avoided meat. Studies in England and Germany demonstrated that vegetarians were  40% less likely to develop cancer. Harvard studies showed that daily meat eaters carry approximately thrice risk of colon cancer. 

Weeding through studies on this topic, a more balanced, composite big picture emerges. What kind, how much, and cooking methods all play a part in the effects of red meat on the digestive system and related cancers.  

Cancers Linked to Red Meat

Breast Cancer – populations consuming higher amounts of fat, especially from animal products have a higher incidence.

Colorectal Cancer – frequent consumption of meat, particularly red meat, is associated with an increased risk.

Distal Colon Cancer - scientists found that women regularly eating red meat had higher rates of distal colon cancer - the section of the colon where feces are stored.

Prostate Cancer - intake of dietary fat from meat and other animal products increases testosterone production, which in turn increases risk. 

Other Cancers –studies have concluded that heavy meat consumption plays a significant role in kidney and pancreatic cancers. 

Carcinogenic Elements in Meat

In 2007  the American Institute for Cancer Research (AICR) published reviews of major studies on food, nutrition and cancer prevention. Research has discovered several mechanisms linking cancer with components of meat. These exist in conventional, grass-fed or wild game: 

·      Meat lacks fiber and other protective nutrients

·      Meat contains animal protein

·      Saturated fat increases the risk of hormone-related cancers

Heme - the iron-containing compound that gives red meat its color metabolizes into cytotoxic compounds (toxic to living cells).

L-Carnitine and TMAO - L-carnitine, an amino acid abundant in red meat gets metabolized into compounds called trimethylamine (TMA), and trimethylamine-N-oxide (TMAO), both strongly linked to cancer and heart disease.  

Neu5GC - a sialic acid molecule in red meat. The human body launches an immune response against this “foreign invader,” leading to the production of antibodies and inflammation and raising cancer risk.

Preservatives – nitrates and nitrites in processed meats are converted into nitrosamines, which are carcinogenic.

Carbon monoxide – is pumped into red meat and tuna to keep them looking fresh in stores. A variety of additives are used to improve the appearance of other foods.

The Effects of Cooking on Meat

Heterocyclic Amines - HCAs, a family of mutagenic compounds, are produced during the high-heat cooking process of many meats. The longer and hotter the meat is cooked, the more these compounds form.

Polycyclic Aromatic Hydrocarbons - Grilling or broiling meat over a direct flame results in fats and juices dropping on hot fire and the production of PAHs, which adhere to the surface of food. They play a significant role in human cancers. 

Navigating the Right Path

As in all things in life, moderation and balance, and care in preparation is the way to go:

Quality. Balance meat with healthy, cancer-fighting foods such as vegetables (specially cruciferous), fruit, whole grains, legumes (beans and peas), nuts and seeds.

Quantity. Consume good-quality, fresh (unprocessed) meats in 3-ounce servings, 3 to 4 times per week.

Cook slow and low. Lower temperatures for longer periods produce fewer carcinogenic compounds. 

Flavor with spices and herbs. Marinate meat in spice and herb mixtures, which reduce formation of carcinogens. 

Tools. Use tongs rather than forks to flip meat on the grill, to avoid carcinogen-forming PAHs.

Cook with Plants. Vegetables, fruit, or any other plant-based food can be cooked at high heat without developing carcinogens.

Eat Fresh. The IARC classified processed meat as a “definite” cause of cancer, or a Group 1 carcinogen – the same group that includes smoking and alcohol. Freshly prepared chicken, other poultry, fish, lean beef, and pork are "safer" than processed - smoked, cured, and salted – meats.

Plant and animal foods both play a symbiotic role in the human diet. Plant foods provide protective elements against animal products and the risks they pose. Animal products provide nutrients that are low or absent from plant foods. The key is to enjoy nutrient-dense items in balance from both the plant and animal kingdoms.

Nutritional sufficiency, gut flora and health, restful sleep, stress management and physical activity are all important.  While nutrient deficiency, gut dysbiosis, poor sleep, high stress and inactivity have all been linked to increased cancer risk.

If you feel you are at risk of colon cancer or want more information about diet and cancer, call Anne Arundel Gastroenterology Associates today at (410) 224-2116  for an appointment with one of our gastroenterologists or request an appointment online.