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 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.
Plant foods are important for many reasons. 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.
This latest research specifically looked at cancer risk. Previously researchers 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 with processed meat, foods like cured meats, sausages, and the like–but not red meat per se. The authors of this study concur with others and suggest 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. Problems with the study population and difficulty teasing apart other lifestyle factors continue to dog researchers. After badgering the public to eat less saturated fat and cholesterol (ie red meat) for over 50 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 have also scrutinized the findings, shining a glaring spotlight on sloppy science and sloppy journalism. 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
2. The actual rate of cancer deaths were nearly the same (9.8 vs. 9.0%). In the low protein cohort 43 of 437 people died of cancer. In the high protein diet 103/1,146 people died of cancer. That is a difference of .07% increase in cancer mortality. Not exactly news.
I suspect no matter how hard epidemiologists try, it is pretty difficult to isolate all the variables. That is the reason that randomized and controlled trials are the gold standard to establish cause and effect. Epi studies can only establish association because all that problematic lifestyle behavior skews the data. This recent study used data collected from NHANES research, a periodic government survey regarding American food habits.
In this study a higher protein intake reportedly increases risk of cancer for middle aged subjects, but is considered protective for those over 65. As Dr. Katz remarks in his own post, “It’s not very likely that what’s good (or bad) for us at 63 suddenly turns bad (or good) for us at 66.” So what is the take away? I like what the researches summed up in one of the critiques, jabbing a pointed finger at sloppy journalism and an even more pointed one at the peer reviewed journal: “A more accurate headline for this study would have been “High protein for those between 50 years to 65 years old who have poor diet and lifestyle habits may be associated with increased cancer risk.”