For more than 50 years, researchers and governmental officials have told us that red meat is bad for our health. Three major reasons are that red meat contains cholesterol and saturated fat, plus grilling red can produce chemicals that cause cancer. The LDL fraction of cholesterol and saturated fat have both been linked to increased risk of cardiovascular disease and death in epidemiological studies.
Some epidemiological studies report a significant link between red meat consumption and cardiovascular disease or death, while others don’t. Two recent meta-analyses (Lee et al. 2013; Micha et al. 2010), each of which combined the results of several studies into a single analysis, did not find a statistically significant association between total meat intake and mortality risk, or between unprocessed red meat consumption and coronary heart disease or type 2 diabetes, respectively.
Epidemiological studies of red meat consumption typically have four serious drawbacks that you need to consider.
First, the AARP-Diet and Health Study found that meat eaters generally don’t make healthy choices. They are more likely to smoke, overeat, exercise less, eat more sugar and fewer fruits and veggies than non-meat eaters. Thus, a significant correlation between meat consumption and mortality may not be due to meat consumption but to unhealthy choices. Epidemiological studies typically control for some unhealthy choices (such a smoking and a poor diet) but not all of them (such as insufficient sleep and lack of social support).
Second, epidemiological studies often don’t distinguish between processed red meat and unprocessed red meat. The former includes sausage, salami, bacon, lunch meats, and ham. The latter includes steaks, stew beef, and hamburger. A recent epidemiological study did distinguish between processed and non-processed red meat consumption in relation to survival. The study followed 74,645 middle-aged Swedish adults over a 15-year period. Researchers found that consumption of 3.6 ounces of processed red meat per day was associated with shorter survival, but that consumption of unprocessed red meat alone was not associated with survival (Bellavia et al. 2014).
Third, epidemiological studies don’t usually distinguish between red meat that’s been grilled or not. Studies suggest that grilling red meat (or chicken for that matter), especially at high temperatures, produces chemicals that cause cancer. Thus, the presence of carcinogenic chemicals reflects more the consequences of high-temperature grilling more than the properties of the red meat.
Fourth, epidemiological studies don’t distinguish between meat that comes from conventionally raised and grass-fed animals. The former refers to animals that spend the last few months of their lives in a feed lot eating grain (and lots of antibiotics). Grain-feeding promotes rapid weight gain and intramuscular fat deposition to make the meat tender. Grass-fed meat comes from animals that spend their entire life on pasture, eating grasses and other plants. Abundant evidence indicates that grass-fed red meat differs substantially in chemical composition from the conventional analog and that all those differences are linked to better health.
But here’s the clincher. If red meat consumption is bad for your health, it follows that vegetarians would live longer than nonvegetarians. Three studies from the United Kingdom paint a different picture. From 1973-1979, the Healthy Food Shopper Study recruited customers of health food shops, members of vegetarian societies, and readers of relevant magazines. The cohort of 10,736 presumably health-conscious persons included 43% vegetarians and 57% nonvegetarians, with follow-up until 1997. During the follow-up period, the standardized mortality rate for both vegetarians and nonvegetarians was 59% of that of the entire United Kingdom. The two other studies produced similar results. These studies suggest that vegetarians are much healthier than average UK citizens but not because the vegetarians don’t eat meat. Evidently, vegetarians and their meat-eating friends both adopt more healthy habits than typical UK citizens, thus accounting for their lower mortality (Key et al. 2003).
What’s the message here? If you eat a lousy diet, don’t take care of yourself, and routinely eat red meat that’s grilled at high temperatures, eating conventional red meat is probably bad for you. But if you eat a high-quality diet, with lots of veggies and fiber and minimal amounts of sugar and white flour, and adopt other health habits, then eating grass-fed meat cooked at low to moderate temperatures is probably good for you. Plus including red meat in your dinner will probably make it more enjoyable.
References
Andrea Bellavia, Susanna C Larsson, Matteo Bottai, Alicja Wolk, and Nicola Orsini. 2014. Differences in survival associated with processed and with nonprocessed red meat consumption. American Journal of Clinical Nutrition 100:924.9.
Timothy J Key, Paul N Appleby, Gwyneth K Davey, Naomi E Allen, Elizabeth A Spencer, and Ruth C Travis. 2003. Mortality in British vegetarians: review and preliminary results from EPIC-Oxford. American Journal of Clinical Nutrition 78(suppl.):533S-8S.
Lee et al. 2013. Meat intake and cause-specific mortality: a pooled analysis of Asian prospective cohort studies. American Journal of Clinical Nutrition 98:1032-41.
Renata Micha, Sarah K. Wallace, and Dariush Mozaffar. 2010. Red and Processed Meat Consumption and Risk of Incident Coronary Heart Disease, Stroke, and Diabetes Mellitus A Systematic Review and Meta-Analysis. Circulation 121:2271-83.
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