Nutrition Performance - “Physicians” Committee for Responsible Medicine and Anti-Protein Propaganda

"Most Americans are too smart to knowingly take dietary advice from PETA [People for the Ethical Treatment of Animals]. But when animal rights activists put on the sheep's clothing of the medical profession, it becomes harder to know who's credible. These so-called “physicians” [Physicians Committee for Responsible Medicine] have a huge hidden agenda. Force-feeding animal rights propaganda to Americans doesn't sound very “responsible” to me, and the established medical community agrees." —David Martosko,

Director of Research

Center for Consumer Freedom

The Physicians Committee for Responsible Medicine (PCRM) is a pseudoscientific association that claims to promote optimal diet for prevention of disease. They “teach” that dietary protein from animal sources is detrimental to health. PCRM's reference to animal sources is key to understanding its true purpose.

PCRM has well-documented ties to the animal rights movement, including over $850,000 in financing from People for the Ethical Treatment of Animals (PETA)*. PCRM president Neal Barnard, a non-practicing psychiatrist, sits on the board of The PETA Foundation with PETA co-founder Ingrid Newkirk. According to Barnard´s quacky book Food for Life, "To give a child animal products is a form of child abuse.” Yeah sure… and according to my recent textbook Bullshit: Basic Science and Practical Aspects, Brandy Dahl lives in my underpants.

The American Medical Association (AMA) calls PCRM a “pseudo-physicians group” (because less than 0.5 percent of physicians are members), has demanded that PCRM stop its “inappropriate and unethical tactics used to manipulate public opinion,” and argues that PCRM has been “blatantly misleading Americans” and “concealing its true purpose as an animal ‘rights’ organization.”

This article examines some of the pseudoscience behind PCRM propaganda.

PCRM Propaganda vs. Scientific Facts

PCRM Propaganda: “For weight loss, studies show that high-protein diets do not work any better than other diets.”

Scientific facts: Results of several recent studies suggest that high-protein, low-carbohydrate diets have their benefits. In addition to sparing fat-free mass (Metabolism, 43:1481-1487, 1994) and producing greater weight and fat loss than high-carbohydrate diets (Int J Obes Relat Metab Disord, 23:528-536, 1999), high-protein diets have been associated with decreases in fasting triglycerides and free fatty acids in healthy subjects and with the normalization of fasting insulin levels in hyperinsulinemic, normoglycemic obese subjects (Int J Obes Relat Metab Disord, 23:1202-1206, 1999; Int J Obes Relat Metab Disord, 23:528-536, 1999).

Furthermore, a 45 percent protein diet reduced resting energy expenditure to a significantly lesser extent than did a 12 percent protein diet (Int J Obes Relat Metab Disord, 23:1202-1206, 1999).

PCRM Propaganda: ”High-protein diets are associated with reduced kidney function. Over time, individuals who consume very large amounts of protein, particularly animal protein, risk permanent loss of kidney function.”

Scientific Facts: According to a literature review by Dr. Mackenzie Walser from the Johns Hopkins School of Medicine published in The Role of Protein and Amino Acids in Sustaining and Enhancing Performance (National Academy Press, 1999), “It is clear that protein restriction does not prevent decline in renal [kidney] function with age, and, in fact, is the major cause of that decline. A better way to prevent the decline would be to increase protein intake... there is no reason to restrict protein intake in healthy individuals in order to protect the kidney.”

Dietary protein restriction has been recommended as a therapeutic approach for delaying the progression of chronic renal failure. However, the results of several recent studies on this subject have been conflicting. The results of the largest randomized clinical trial, “The Modification of Diet in Renal Disease (MDRD),” did not demonstrate a benefit of dietary protein restriction on progression of renal disease (New Engl J Med, 330:877-884,1994).

PCRM Propaganda: “Very high protein intake is known to encourage urinary calcium losses and has been shown to increase risk of fracture in research studies.”

Scientific Facts: Increasing dietary protein increases urine calcium excretion such that for each 50-gram increment of protein consumed, an extra 60 milligrams of urinary calcium is excreted. It follows that the higher the protein intake, the more urine calcium is lost and the more negative calcium balance becomes. Since 99 percent of the body´s calcium is found in bone, one would hypothesize that high-protein-induced hypercalciuria would result in high bone resorption and increased prevalence of osteoporotic-related fractures.

However, the epidemiological and clinical data addressing this hypothesis are controversial. On one hand, most, but not all, epidemiological studies found a positive association between protein intake and bone mineral density (BMD). On the other hand, many, but certainly not all, studies report higher fractures in groups consuming a high-protein diet.

There is growing evidence that a low-protein diet has a detrimental effect on bone. For example, Dr. Kerstetter and colleagues reported that in healthy young women, acute intakes of a low-protein diet (0.7 grams [g] of protein per kilogram [kg] of body weight) decreased urinary calcium excretion with accompanied secondary hyperparathyroidism. (In secondary hyperparathyroidism, a high level of PTH occurs as a compensation for hypocalcemia rather than as a primary abnormality of the parathyroid gland). The etiology of the secondary hyperparathyroidism is due, in part, to a significant reduction in intestinal calcium absorption during a low-protein diet.

Further, in a recent short-term intervention trial, Dr. Kerstetter and co-workers evaluated the effects of graded levels of dietary protein (0.7, 0.8, 0.9 and

1.0 grams protein/kg) on calcium homeostasis. Secondary hyperparathyroidism developed by day four of the 0.7 and 0.8 grams of protein per kilogram diets (due to the decreased intestinal calcium absorption), but not during the 0.9 or 1.0 grams of protein per kilogram diets in eight young women. Similarly, when Dr. Giannini and colleagues restricted dietary protein to 0.8 grams of protein per kilogram, they observed an acute rise in serum PTH in 18 middle-aged hypercalciuric adults. Taken together, both of studies suggest, at least in the short term, that RDA for protein (0.8 g/kg) does not support normal calcium homeostasis.

The long-term consequences of restricted protein intake on calcium and bone metabolism are unknown, but could potentially be an important and unrecognized problem. Analysis of available data from the U.S. Department of Agriculture indicated that 31 percent of women over the age of 20 consume less protein than the 1989 RDA. Only half these women (i.e., 15 percent of women over age 20) considered their own diets to be too low in dietary protein.

PCRM Propaganda: “Typical high-protein diets are extremely high in dietary cholesterol and saturated fat… Such diets pose additional cardiovascular risks, including increased risk for cardiovascular events immediately following a meal.”

Scientific facts: Overwhelming evidence shows that the addition of saturated fat to an otherwise low-fat diet will adversely affect serum (blood) markers of atherosclerotic cardiovascular disease. However, some evidence indicates there may not be a simple relationship between increasing dietary intake of saturated fat and cholesterol and the serum markers of atherosclerotic cardiovascular disease. Some humans can adapt to increased intake of dietary cholesterol by decreasing absorption and increasing excretion (New Engl J Med, 324:896-899,1991). Dr. Westman and co-workers reported decreases in total cholesterol and total triglyceride levels and increases in HDL (“good cholesterol”) concentrations in patients prescribed a ketogenic high saturated fat diet (Am J Med,113:30-36,2002; see my article “Low-Carbohydrate Ketogenic Diet: Friend or Foe?” in the January issue of MD).

The aim of a recent study by Dr. James Hayes and colleagues at Christina Health Care Services was to determine whether a diet high in saturated fat and avoidance of starch (HSF-SA) results in weight loss without adverse effects on serum lipids in obese non-diabetic patients (Mayo Clin Proc, 78:1331-1336, 2003). Twenty-three patients with atherosclerotic cardiovascular disease participated in this prospective six-week trial. All patients were obese and had been treated with statins before entry into the trial. Authors concluded that the “HSF-SA diet results in weight loss after six weeks without adverse effects on serum lipids… and further weight loss with a lipid-neutral effect may persist for up to 52 weeks.”

The earliest humans consumed a considerable amount of meat. From the available evidence, Drs. Eaton and Konner concluded that the Paleolithic people generally ate much more protein and less fat than we do (N Engl J Med, 312:283,1985). Their diet contained more essential fatty acids and much higher ratios of polyunsaturated to saturated fats, although their cholesterol intake was high. Also, their intake of dietary fiber was much higher than ours, while sodium intake was remarkably low.