The researchers never said, ” Cheeseburgers are as bad as smoking”.
That was the title of the press release, and the media ate it up. Call it science journalism by proxy. A press release allows science to be spoon fed to journalists who don’t know the subject matter, and are too often content to regurgitate the effective but often less than accurate story offered by the researcher’s public relations team. Sound bites dominate the conversation about food and nutrition, and we all suffer the consequences.
Proponents of a plant based diet emphasize its nutritional attributes, herald the healthier profiles of plant eaters, and often position vegan and vegetarian diets as the only way to effectively feed a growing population. Paleo and other high protein devotees talk of greater satiety and more effective fat loss. The public is played like a ping pong ball in the debate.
Fruits, vegetables, whole grains and legumes have earned their place at the table. But a plant based diet doesn’t necessarily mean a no meat diet. Many people feel better when they eat enough protein, and often they want/need it from animal products. There is a reason that as wealth increases in developing countries, so does the demand for animal products–and it’s not just about status.
CHEESEBURGERS AND RISK OF DISEASE
So what does this particular research add to the debate regarding protein in the diet? Not much. We already know the benefit of eating enough vegetables, nuts, and monounsaturated fatty acids (ie: olive oil) Likewise, we have already been warned about trans fats, too much sugar, and refined starch. There is strong evidence in the scientific literature for both messages. The evidence linking red meat with disease is considered moderate or weak.
USC researchers specifically looked at cancer risk. Previously researchers have already weighed in on the subject, and in the EPIC study, Rohrman and colleagues found no increased risk of disease associated with eating red meat. They did identify some increased risk linked with eating processed meat, foods like cured meats, sausages, and the like–but only in previous and current smokers. Rohrman suggests that the decreased disease observed in vegetarians may have more to do with the sum total of healthful behaviors rather than the absence of meat in their diet.
ARE ANIMAL PRODUCTS REALLY THAT HARMFUL?
A few days after the blogosphere lit up with “Cheeseburgers as bad as cigarettes”, one brave soul started poking holes in the findings. Studying populations and teasing apart lifestyle factors trips up many epidemiological efforts. In this case, health messages over the past four decades probably tainted the outcome. After badgering the public to eat less saturated fat and cholesterol (ie red meat) for over 40 years, it seems a significant number of people who eat red meat also ignore other health recommendations. Meat eaters tend to smoke more, don’t exercise, don’t eat fruits and vegetables. and generally don’t live a healthful lifestyle.
Others scientists shine a spotlight on the sloppy science in their critiques. Comments attached to the online abstract detail the scientific squabble, with one scientist taking issue with how the numbers were crunched. A few glaring details stand out to me:
1. Researchers didn’t distinguish the type of carbohydrates consumed, a rather significant omission considering what we understand about the role of high glycemic carbs. What happens when people who eat meat and cheese also eat a significant amount of fruit and vegetables instead of refined sugar and starch?
2. The actual rate of cancer deaths were nearly the same for both high meat and low meat eaters. (9.8 vs. 9.0%). In the low protein cohort 10 people die of cancer–about 0.1% of the population. In the high protein group 17 people died of cancer–about 0.17 percent. The difference is 0.07%–and that is 70% more than the 0.1% cancer rate of low protein eaters. These mathematical gymnastics allowed a press release to scare you by stating that eating meat and cheese causes a 70% increase in cancer risk. Sensational, but not helpful.
I suspect no matter how hard epidemiologists try, it is basically impossible to isolate all the variables. This is the reason that randomized and controlled trials are the gold standard to establish cause and effect. Epidemiological studies can only establish association because all those problematic lifestyle behaviors skew the data. We need to remember that every time a press release offers us advice about what to eat.