Thursday, March 22, 2012

Red meat and mortality

A recent study found that red meat was deadly:
Small quantities of processed meat such as bacon, sausages or salami can increase the likelihood of dying early by a fifth, researchers from Harvard School of Medicine found. Eating steak increases the risk of early death by 12%. The study found that cutting the amount of red meat in peoples’ diets to 1.5 ounces (42 grams) a day, equivalent to one large steak a week, could prevent almost one in 10 early deaths in men and one in 13 in women.
My personal belief is that a cheeseburger is the healthiest food that you can eat, so I am always on the lookout for any evidence to the contrary.

This essay enumerates weaknesses of the study:
The authors claim that 9.3 per cent of deaths in men and 7.6 per cent of deaths in women could be avoided by eating little or no red meat. To put that into some back-of-an-envelope statistical perspective: multiplying that 9.3 per cent by the 20 per cent who actually died shows that about 1.8 per cent of red-meat eaters would die by the time they were 75 because of their meat-eating habit. ...

A serious problem with the present study is that while the researchers excluded anyone who had a heart problem or cancer at the time the study started, there were some pretty important differences between the groups examined. In both the male and female groups, at the start of the study the people who ate the most red meat were also about twice as likely to be diabetic and took much less exercise. The men in the high red-meat group were also three times as likely to be smokers and drank much more, too. (Women who like their red meat also liked booze and fags more than their burger-dodging sisters did, but the differences weren’t as large.)

There was also a clear trend in total calories consumed per day for both men and women. The low red-meat group consumed far fewer calories each day (1,659 for men and 1,202 for women) then the highest red-meat group (2,396 for men and 2,030 for women). These are enormous differences.

Can the researchers really be sure that the differences in meat consumption were to blame for the fairly small difference in health outcomes, rather than all the other differences between the groups?
(This was on a British site, where a "fag" means a cigarette.)

If red meat were really so bad, wouldn't they be able to do a more convincing study to prove it?

The trouble with this sort of uncontrolled study is that it finds healthier people who live longer, and it finds that those healthy people have an assortment of habits that are generally perceived as healthy, but it is very hard to figure out what is causing the healthiness. Maybe avoiding red meat is making people healthier, but I think that it is more likely that the healthier people have been brainwashed to think that they need to avoid red meat to stay healthy.

The essay concludes:
What is really striking is that the eat-meat-die-young panic keeps rearing its ugly head so regularly, based on study after study with equally feeble risk ratios and numerous confounding factors. This suggests that the constant desire to scare those of a carnivorous bent has little to do with the evidence – which is shakier than a cow with BSE – and more to do with the prejudices of those who want us all to live a less red-blooded lifestyle. The particular desire to promote lentil-munching over hot dogs and burgers rather suggests a general sniffiness towards mass-produced food, too.

The most accurate answer to the question of whether red meat and processed meat are bad for you is this: we just don’t know. My hunch is that the health risks are non-existent – in practical terms, they are pretty much irrelevant – but given the difficulties of conducting this research, it’s hard to believe we could ever know if one particular type of food is especially bad for us. Still, that won’t stop the medics and the researchers from trying to enforce their food rules on us anyway.
Physicians have claimed for decades that red meat causes high blood cholesterol and high blood cholesterol causes heart disease, but that reasoning is faulty also.


A K Haart said...

"I think that it is more likely that the healthier people have been brainwashed to think that they need to avoid red meat to stay healthy."

Good point, and as time goes on the effect may become more pronounced and the correlation more misleading.

Roger said...

Smoking is correlated with all sorts of health problems. There is an obvious connection with some of them, like lung cancer, but not others. My theory is that healthy people do not smoke for cultural and other reasons, and that smoking is not really as bad as the studies indicate.

Igor Alexander said...

The problem with processed meats is the additives and preservatives that are in them, not that they are meat products.

If beef is causing health problems, it's likely a result of the current low-fat meat craze. American Indians and early European settlers to the Americas knew that if they could only procure lean meat during the winter, they would probably die. The body needs the fat portion of meat as much as the protein.

Lean ground beef gives me the runs, so I always get medium. As an added bonus, the fattier the meat, the better it tastes. Ever since I started eating medium ground, I've been finding lean beef inedible.