Red Meat and Mortality Correlations
Here is a study claiming a noticeable impact on mortality rates from eating red meat. Weight is considered to some degree via body mass index, but I have to wonder if this only reflects a modest association of red meat consumption with other, less healthy lifestyle choices rather than an actual red-meat-based mechanism - as an obvious candidate mechanism for that isn't also present in all meat consumption isn't springing to mind: researchers "found that red meat consumption is associated with an increased risk of total, cardiovascular, and cancer mortality. The results also showed that substituting other healthy protein sources, such as fish, poultry, nuts, and legumes, was associated with a lower risk of mortality. ... [Researchers] observed 37,698 men from the Health Professionals Follow-up Study for up to 22 years and 83,644 women in the Nurses' Health Study for up to 28 years who were free of cardiovascular disease (CVD) and cancer at baseline. Diets were assessed through questionnaires every four years. ... One daily serving of unprocessed red meat (about the size of a deck of cards) was associated with a 13% increased risk of mortality, and one daily serving of processed red meat (one hot dog or two slices of bacon) was associated with a 20% increased risk. ... These analyses took into account chronic disease risk factors such as age, body mass index, physical activity, family history of heart disease, or major cancers. ... Replacing one serving of total red meat with one serving of a healthy protein source was associated with a lower mortality risk: 7% for fish, 14% for poultry, 19% for nuts, 10% for legumes, 10% for low-fat dairy products, and 14% for whole grains. The researchers estimated that 9.3% of deaths in men and 7.6% in women could have been prevented at the end of the follow-up if all the participants had consumed less than 0.5 servings per day of red meat."
Link: http://www.sciencedaily.com/releases/2012/03/120312162746.htm
I was thinking along the same lines when I read/heard of this study. I am a non smoking red meat eater, but I am thinking that there is more than a trivial corelation between red meat eating among the broad population and some unhealthy behaviors such as smoking, stimulants and binge drinking, it is not clear to me that the study took into account all behavior variables necessary.
Something I've considered in the past two years in relation to the above post:
That red meat consumption is actually a marker of consumption of meat cooked at high temperatures (e.g. over open flame), and the latter is the larger contributor to increased death rate.
The production of things like heterocyclic amines are catalyzed by cooking meats at high temperatures, as are advanced glycation endproducts.
Here is a thought experiment I sometimes ask myself, to test if this may be the case:
How often have you heard of people steaming a steak, hamburger, or ribs? How are these meats usually cooked?
In contrast, how often are lentils, nuts, and fish cooked over an open flame until they turn black (like the above meats often are)?
Confounding this thought experiment is the fact that chicken is often cooked over an open flame, and nuts are roasted.
Still, if I eat red meat (which is very rarely), I make a point to cook it (actually *all* foods) at low temperature. 300-500 F and is absolutely unnecessary to cook food, and likely quite harmful (consider water boils at 212, and it's advised that most meats should be cooked to between 160 and 180 F).