Dr. Michael Greger is a physician on staff at the Humane Society of the United States.
Medical credentials aside, that post alone removes him from any semblance of scientific objectivity and puts him squarely into full-on propaganda mode.
A position confirmed by the titles of his recent blog posts and video clips:
- Estrogenic Cooked Meat Carcinogens
- Vegan Men: More Testosterone But Less Cancer
- Cancer-Proofing Your Body (through a vegan diet, ’case you didn’t know)
That last report focused on Nathan Pritikin’s well-publicized approach to preventing heart disease—which, it should be noted, includes healthy doses of exercise, as well as healthy choices in food.
Which brings us to a discussion of the concept of multivariate causation, or the idea that complex health issues—such as cancer or heart disease—are not traceable to a single source. No one food causes heart attacks, and no single intervention prevents them. Even Greger admits that.
“One of the reasons it’s so difficult to study the relationship between diet and cancer is because many dietary behaviors are associated with non-dietary behaviors,” he posted recently on his site (www.nutritionfacts.org). “For example, it used to be thought that coffee-drinking caused cancer, because people who drink coffee are more likely to be smokers. Actually, coffee consumption may decrease cancer risk.”
Now it gets interesting.
“That reason is the same reason it’s so difficult to study cancer among meat eaters,” Greger wrote. “Historically, those eating vegetarian have been noted to have lower cancer rates, but maybe it’s just because they exercise more, or smoke less or inhale less diesel fumes because they all own a Prius.”
Right. It’s the car that makes the difference.
“I profiled new data that attempts to control for non-dietary factors by effectively comparing vegetarians only to meat eaters who are as slim as vegetarians, exercise as much, smoke as little, and even eat roughly the same amount of fruits and vegetables,” he continued. “When vegetarians were compared only to healthy meat eaters with healthier diets, researchers still found the incidence of all cancers combined was lower among vegetarians.
The biggest difference between veggies and meat-eaters was in the risk for cancers of the blood and bone marrow, such as non-Hodgkins lymphoma and various types of leukemia. But guess what was the most significant risk factor?