It is common knowledge that meat contains a substantial source of protein necessary for proper function of human muscles. However, there has been an extensive debate regarding various studies evaluating the health risks of red meat consumption. Some study researchers have found a correlation between certain types of red meat and serious health consequences.

Red meat contains an abundance of the compound L-carnitine. According to a recent study released in 2013 at the Cleveland Clinic, consuming red meat delivers L-carnitine to the bacteria living in the stomach, which metabolize the compound into trimetylamine-N-oxide, or TMAO. The compound TMAO has been revealed to cause atherosclerosis, a condition that results in clogged arteries due to cholesterol particles. 

Research studies, thus far, have been inconclusive as to whether or not unprocessed red meats, such as fresh cuts of beef, lamb and pork, are associated with heart disease. In 2012, the Harvard School of Public Health evaluated the most prominent findings of available studies on this correlation. It found that the consumption of processed meats, and not red meats, were associated with a higher risk for cardiovascular disease and diabetes. Processed meats include hot dogs, bacon, sausage, salami, and deli meats. They only found a weak association between unprocessed meat consumption and heart disease.

A study conducted by the Harvard School of Public Health in 2012 found that individuals who eat a substantial amount of processed meat are at a higher risk for cardiovascular disease and cancer mortality. The research suggests that red meat substituted with alternative healthy protein sources is correlated with a lower mortality risk. 

Another study in 2014 at the Harvard School of Public Health concluded that a higher intake of red meat during adolescent years was linked to a 22% higher risk for pre-menopausal breast cancer and 13% overall increased risk for breast cancer. The research found that substitution of red meat with other protein sources may reduce pre-menopausal breast cancer risk. Maryam Farvid, the lead researcher for the study suggests that women should consume red meat once a week to decrease their risk for breast cancer.

The American Heart Association (AHA) recommends substituting red meat with healthy meats like chicken or fish or vegetable proteins, like beans, as red meats contain more cholesterol and saturated fat than these healthier alternates. They suggest that you should limit your intake of lean meat, skinless chicken, or fish to less than 6 ounces per day. In order to lower the saturated fat content and cholesterol of red meats, choose lean cuts of meat which usually contain the words “round”, “loin” or “sirloin” on the packaging, as these are the healthiest red meats. Meats should be trimmed to remove as much fat as possible, prior to cooking. AHA recommends that red meats be baked, broiled, or grilled.

This information, although alarming, should not lead you to believe that a vegetarian diet is the only answer. Red meat intake should be reduced if you consume more than the recommended value. Talk to your healthcare provider about your red meat intake, as well as your risk factors for developing any disorders or life-threatening conditions.

References:

Eat More Chicken, Fish and Beans than Red Meat [Internet]. American Heart Association; 2013 Jan 10 [updated 2014 Feb 19; cited 2014 Nov 1]. Available from: http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/HealthyEating/Eat-More-Chicken-Fish-and-Beans-than-Red-Meat_UCM_320278_Article.jsp

Pendick, D. New study links L-carnitine in red meat to heart disease [Internet]. Harvard Health Publications; 2013 Apr 17 [cited 2014 Nov 1]. Available from: http://www.health.harvard.edu/blog/new-study-links-l-carnitine-in-red-meat-to-heart-disease-201304176083

Koeth RA, Wang Z, Levinson BS, Buffa JA, Org E, Sheehy BT, Britt EB, Fu X, Wu Y, Li L, Smith JD, DiDonato JA, Chen J, Li H, Wu G, Lewis JD, Warrier M, Brown JM, Krauss RM, Tang WHW, Bushman FD, Lusis AJ, Hazen SL. Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis. Nature Medicine. 2013; 19:576-585. 

Roeder, A. Red meat consumption and breast cancer risk [Internet]. Harvard School of Public Health; 2014 Oct 9 [cited 2014 Nov 1]. Available from: http://www.hsph.harvard.edu/news/features/red-meat-consumption-and-breast-cancer-risk/

Pan A, Sun Q, Bernstein AM, Schulze MB, Manson JE, Stampfer MJ, Willett WC, Hu FB. Red meat consumption and mortality: results from 2 prospective cohort studies. Arch Intern Med. 2012; 172(7):555-563. 

Meat, Poultry and Fish [Internet]. American Heart Association [updated 2014 Aug 11; cited 2014 Nov 1]. Available from: http://www.heart.org/HEARTORG/GettingHealthy/NutritionCenter/Meat-Poultry-and-Fish_UCM_306002_Article.jsp

Farvid MS, Cho E, Chen WY, Eliassen AH, Willett WC. Adolescent meat intake and breast cancer risk. International Journal of Cancer. 2014; doi: 10.1002/ijc.29218.

Helpful Peer-Reviewed Medical Articles:

Azadbakht, L., & Esmaillzadeh, A. (2009). Red meat intake is associated with metabolic syndrome and the plasma C-reactive protein concentration in women. The Journal of nutrition, 139(2), 335-339.

McAfee, A. J., McSorley, E. M., Cuskelly, G. J., Moss, B. W., Wallace, J. M., Bonham, M. P., & Fearon, A. M. (2010). Red meat consumption: An overview of the risks and benefits. Meat science, 84(1), 1-13.

Bingham, S. A., Hughes, R., & Cross, A. J. (2002). Effect of white versus red meat on endogenous N-nitrosation in the human colon and further evidence of a dose response. The Journal of nutrition, 132(11), 3522S-3525S.

Williams, P. (2007). Nutritional composition of red meat. Nutrition & Dietetics, 64(s4), S113-S119.

Pan, A., Sun, Q., Bernstein, A. M., Schulze, M. B., Manson, J. E., Stampfer, M. J., ... & Hu, F. B. (2012). Red meat consumption and mortality: results from 2 prospective cohort studies. Archives of internal medicine,172(7), 555-563.