High Protein Diets: Separating Fact from Fiction

By: Stephen Byrnes, PhD, RNCP

This paper is a response to "High-Protein Diets—Are You Losing More Than Weight?" by Monique Gilbert. The article appeared in the American Naturopathic Medical Association's quarterly publication MONITOR (Vol.5, #4, 2001) and is located at The American Naturopathic Medical Association.

In the December issue of the Monitor, there was an unreferenced article by a self–styled "health advocate" named Monique Gilbert that deserves considerable comment for the large amount of errors and misinformation it contained.

"High-Protein Diets—Are You Losing More Than Weight?" is little more than a vegan and soy propaganda piece. If the propaganda were accurate, one could forgive Ms. Gilbert for her zeal. In this case, however, it is not and inaccuracies cost lives.

Clinically, I have used low-carbohydrate, high fat and protein diets to very good effect, especially with those conditions that are worsened by excessive carbohydrate intake, e.g., diabetes, chronic fatigue, fibromyalgia, and heart disease.

When properly practiced, low-carb diets are not harmful. Furthermore, if one were to follow Ms. Gilbert's dubious nutritional advice as given in her article, one would actually increase one's chances of contracting a number of debilitating diseases such as cancer, heart disease, osteoporosis, and diabetes.

Gilbert begins her piece by rightly pointing out the vital need for protein in the human diet. Unfortunately, the errors begin creeping in shortly thereafter. She states that, "Excessive protein consumption, particularly animal protein, can result in heart disease, stroke, osteoporosis, and kidney stones."

Though she does not list it, Gilbert would no doubt include cancer as a disease caused by animal protein intake. As I stated at the beginning, the article is unreferenced so these claims have no backing. I have no idea where Gilbert got her "facts" from, but it is certainly not from the scientific literature.

It is excessive carbohydrate intake, not protein or animal protein intake, that can result in heart disease and cancer (1). Readers should note that the type of diet Gilbert advocates in her article is a high carbohydrate one because that is exactly what diets that are low in protein and fat are.

Furthermore, the idea that animal products, specifically protein, cholesterol, and saturated fatty acids, somehow factor in causing atherosclerosis, stroke, and/or heart disease is a popular idea that is not supported by available data, including the field of lipid biochemistry (2).

The claim that animal protein intake causes calcium loss from the bones is another popular nutritional myth that has no backing in nutritional science. The studies that supposedly showed protein to cause calcium loss in the urine were NOT done with real, whole foods, but with isolated amino acids and fractionated protein powders (3).

When studies were done with people eating meat with its fat, NO calcium loss was detected in the urine, even over a long period of time (3). Other studies have confirmed that meat eating does not affect calcium balance (4) and that protein promotes stronger bones (5). Furthermore, the saturated fats that Gilbert thinks are so evil are actually required for proper calcium deposition in the bones (6).

The reason why the amino acids and fat-free protein powders caused calcium loss while the meat/fat did not is because protein, calcium, and minerals, require the fat-soluble vitamins A and D for their assimilation and utilization by the body. When protein is consumed without these factors, it upsets the normal biochemistry of the body and mineral loss results (7). True vitamin A and full-complex vitamin D are only found in animal fats.

If the protein-causes-osteoporosis theory teaches us anything, it is to avoid fractionated foods (like soy protein isolate, something Gilbert would no doubt encourage readers to consume given her zeal for soy) and isolated amino acids, and to eat meat with its fat.

New evidence shows that men and women who ate the most animal protein had better bone mass compared to those who avoided it (8) and that vegan diets (most likely also advocated by Gilbert) place women at a greater risk for osteoporosis (9).

The claim that protein intake leads to kidney stones is another popular myth that is not supported by the facts. Although protein restricted diets are helpful for people who have kidney disease, eating meat does not cause kidney problems (10). Furthermore, the fat-soluble vitamins and saturated fatty acids found in animal foods are pivotal for properly functioning kidneys (11).

Gilbert's explanation as to how meat supposedly "acidifies" the blood, leading to greater mineral loss in the urine is also incorrect. Theoretically, the sulphur and phosphorus in meat can form an acid when placed in water, but that does not mean that is what happens in the body.

Actually, meat provides complete proteins and vitamin D (if the fat or skin is eaten), both of which are needed to maintain proper acid-alkaline balance in the body. Furthermore, in a diet that includes enough magnesium and vitamin B6 and restricts simple sugars, one has little to fear from kidney stones (12).

Animal foods like pork, beef, lamb, and fish are good sources of both nutrients as any food and nutrient content table will show. It also goes without saying that high protein/fat and low-carbohydrate diets are devoid of sugar.

Gilbert's contention that the weight loss on high-protein diets is mostly from water loss is strange given that low-carb proponents like Robert Atkins, MD, tell their devotees to drink lots of water while on the diet. Initially, there is a water loss (as with any diet), but the high water intake afterwards would certainly offset any more drastic "water losses."

She further claims that weight loss occurs on high protein/fat diets because the person eats less food because he or she gets fuller faster on fat. Given that fat has more than twice as many calories than either protein or carbohydrate, this explanation is far from satisfactory.

In other words, you may not eat as many carbohydrates as you did before you went on the high protein diet, but because you're ingesting more fat, which has over twice as many calories as carbohydrate, your actual caloric intake is likely to stay the same or be higher than it was before.

Gilbert's claim that , "Plant-based proteins, like that [sic] found in soy, lowers [sic] LDL cholesterol and raises HDL (good) cholesterol. This prevents the build up of arterial plaque which leads to atherosclerosis . . . and heart disease, thus reducing the risk [of] heart attack and stroke," is yet another nutritional fantasy in her article that, although popular, is not true.

The HDL/LDL theory has been thoroughly debunked by a number of prominent researchers (13) and LDL serves many useful functions in the body--there is nothing "bad" about it (14). Cholesterol is actually used by the body as an antioxidant (15); vegetarian diets do not protect against atherosclerosis or heart disease (16); and female vegans have higher rates of death from heart disease than female meat eaters (17).

Gilbert's contention that, "Vegetable-protein diets enhance calcium retention in the body," is simply wrong as "vegetable proteins" do not contain the fat-soluble vitamins A and D which are needed to assimilate calcium (and protein and other minerals).

Furthermore, numerous plant compounds like oxalates and phytates inhibit calcium absorption. Unfermented soy products, in particular, are noted for their high phytic acid content and phytates block mineral absorption (18).

Soybeans and soy food products are also noted for their high oxalic acid content as a recent study showed (19). The authors of this study concluded that soybeans and soy foods (as well as some other legumes like lentils) should not be eaten by people with a history of oxalate kidney stones.

Gilbert's recommendation for us to replace vegetable protein for animal protein and unsaturated fats "like olive and canola oils" for saturated fats, is dubious at best and dangerous at worst. A number of recent and prior studies catalog the veritable witches brew of toxins found in processed soy products (20) and canola oil has caused vitamin E deficiencies in lab animals (21).

Canola oil is also quite susceptible to rancidity due to its high level of alpha-linolenic acid; in the deodorization process used with canola oil, harmful trans-fatty acids are created (22). Are Gilbert's recommendations sound or sane for health-conscious people?

Lastly, studies have not borne out the claims that vegetarians have lower cancer rates than the general population. A large study on vegetarian California 7th Day Adventists showed that, while the Adventists had slightly lower rates for some cancers, their rates of malignant melanoma; Hodgkin's disease; and uterine, prostate, endometrial, cervical, ovarian, and brain cancers were higher than the general population, some quite significantly.

In the paper, the authors wrote that, Meat consumption, however, was not associated with a higher [cancer] risk. And that, No significant association between breast cancer and a high consumption of animal fats or animal products in general was noted. (23)

Indeed, Dr. Emmanuel Cheraskin's survey of 1040 dentists and their wives showed that those with the fewest health problems as measured by the Cornell Medical Index had the MOST protein in their diets (24).

The facts are that high-protein diets, when consumed in balance with enough water, fat and fat-soluble vitamins, and nutritional factors from non-starchy vegetables, ARE healthy. They are not guilty of the things Gilbert blames on them.

Minimally processed animal foods like beef and lamb are healthy foods that are rich in a number of nutrients that protect and enhance several body systems: taurine; carnitine; creatine; glutathione; vitamins A; D; several of the B-complex, including B6 and B12; minerals like chromium, magnesium, sulphur, iron, zinc, and phosphorus; complete proteins; and coenzyme Q10, needed for a healthy heart.

If readers want to get an accurate assessment of lower-carbohydrate diets, they should check out reliable books on the subject (25) and not fatuous articles about them by misinformed individuals like Monique Gilbert.

Notes

1. F. Jeppesen and others. Effects of low-fat, high-carbohydrate diets on risk factors for ischemic heart disease in post-menopausal women. Am J Clin Nutr, 1997; 65:1027-1033. Mensink and Katan. Effect of dietary fatty acids on serum lipids and lipoproteins: a meta-analysis of 27 trials. Arterio Thromb, 1992, 12:911-9; I. Zavaroni and others. Risk factors for coronary artery disease in healthy persons with hyperinsulinemia and normal glucose tolerance. New Eng J Med, 1989, Mar 16, 320:11:702-6; J. Witte and others. Diet and premenopausal bilateral breast cancer: a case control study. Breast Canc Res & Treat, 1997, 42:243-251; S. Francheschi and others. Intake of macronutrients and risk for breast cancer. Lancet, 1996, 347:1351-6; S. Francheschi and others. Food groups and risk of colo-rectal cancer in Italy. Inter J Canc, 1997, 72:56-61; Seely, and others. Diet Related Diseases--The Modern Epidemic (AVI Publishing; CT), 1985, 190-200; WJ Lutz. The colonisation of Europe and our Western diseases. Med Hypoth 1995, 45:115-120; D. Forman. Meat and cancer: a relation in search of a mechanism. The Lancet. 1999;353:686-7
2. Uffe Ravnskov, MD, PHD. The Cholesterol Myths (New Trends Publishing; Washington, D.C.), 2000; Mary Enig. Know Your Fats: The Complete Primer on Fats and Cholesterol (Bethesda Press; Maryland), 2000, 76-81; Russell Smith and Edward Pinckney. Diet, Blood Cholesterol, and Coronary Heart Disease: A Critical Review of the Literature (Vector Enterprises; California), 1991; The Cholesterol Conspiracy (Warren Greene, Inc.; USA), 1991; Stephen Byrnes. Diet and Heart Disease: Its NOT What You Think, (Whitman Books; 2001), 25-52; George V. Mann, ed. Coronary Heart Disease: The Dietary Sense and Nonsense, (Veritas Society; London), 1993.
3. H. Spencer and L. Kramer. Factors contributing to osteoporosis. J of Nutr, 1986, 116:316-319; Further studies of the effect of a high protein diet as meat on calcium metabolism. Amer J Clin Nutr., 1983, 37:6: 924-9.
4. J. Hunt and others. High-versus low meat diets: Effects on zinc absorption, iron status, and calcium, copper, iron, magnesium, manganese, nitrogen, phosphorus, and zinc balance in postmenopausal women. Amer J Clin Nutr, 1995, 62:621-32; Spencer, Osis, and Kramer, Do protein and phosphorus cause calcium loss? J Nutr 1988 Jun;118(6):657-60.
5. C. Cooper, and others. Dietary protein and bone mass in women. Calcif Tiss. Int., 1996, 58:320-5.
6. BA Watkins and others. Importance of vitamin E in bone formation and in chondrocyte function. American Oil Chemists Society Proceedings, 1996, at Purdue University; "Food Lipids and Bone Health" in Food Lipids and Health, McDonald and Min, Editors, (Marcel Dekker Co.; NY), 1996.
7. S. Fallon and M. Enig. Dem bones--do high protein diets cause osteoporosis? Wise Traditions, 2000, 1:4:38-41. Also posted at westonaprice.org
8. RG Munger and others. Prospective study of dietary protein intake and risk of hip fracture in postmenopausal women. Amer J Clin Nutr, 1999, 69:1:147-52; MT Hannan and others. Effect of dietary protein on bone loss in elderly men and women: The Framingham Osteoporosis Study. J Bone & Min Res, 2000, 15:2504-2512.
9. Chiu JF; Lan SJ; Yang CY, and others. Long-term vegetarian diet and bone mineral density in postmenopausal Taiwanese women. Calcif Tissue Int, 1997; 60: 245-9; EM Lau, T Kwok, J Woo, and others. Bone mineral density in Chinese elderly female vegetarians, vegans, lacto-vegetarians and omnivores. Eur J Clin Nutr 1998;52:60-4.
10. J. Dwyer and others. Diet, indicators of kidney disease, and late mortality among older persons in the NHANES I Epidemiologic Follow-up Study. Amer J of Pub Health, 1994, 84:(8): 1299-1303.
11. M. Enig. Saturated fats and the kidneys. Wise Traditions, 2000, 1:3:49. Posted at westonaprice.org.
12. V. Rattan and others. Effect of combined supplementation of magnesium oxide and pyrodoxine in calcium-oxalate stone formers. Urol Res, 1994, 22(3):161-5; NJ Blacklock. Sucrose and idiopathic renal stone. Nutr Health, 1987, 5(1): 9-17.
13. See references for note number two.
14. M. Enig. Know Your Fats, 258.
15. E. Cranton and JP Frackelton. J of Holistic Med, 1984, Spring/Summer, 6-37.
16. Russell Smith, op cit.; L. Corr and M. Oliver. The low-fat/cholesterol diet is ineffective. Eur Heart J, 1997, 18:18-22; F. McGill and others. Results of the International Atherosclerosis Project. Clin Lab Invest, 1968, 18:(5):498; Herrmann, Schorr, Purschwitz, Rassoul, Richter. Total homocysteine, vitamin B (12), and total antioxidant status in vegetarians. Clin Chem 2001 Jun;47(6):1094-101; EA Enas. Coronary artery disease epidemic in Indians: a cause for alarm and call for action. J Indian Med Assoc 2000 Nov;98(11):694-5, 697-702.
17. Ellis, Path, Montegriffo. Veganism: Clinical findings and investigations. Amer J Clin Nutr, 1970, 32:249-255.
18. HH Sandstead. Fiber, phytates, and mineral nutrition. Nutr Rev, 1992, 50:30-1; AH Tiney. Proximate composition and mineral and phytate contents of legumes grown in Sudan. J Food Comp and Analy, 1989, 2:67-68; see also S. Fallon and M. Enig, "The Ploy of Soy," posted at westonaprice.org.
19. LK Massey and others. Oxalate content of soybean seeds, soy foods, and other edible legumes. J Agric Food Chem, 2001, Sep. 49:9:4262-6.
20. See research abstracts posted at Soy On Line Services, New Zealand.
21. FD Sauer and others. Additional Vitamin E required in milk replacer diets that contain canola oil. Nutr Res., 1997, 17: 259-262.
22. M. Enig, Know Your Fats, 120-1,195-6.
23. Mills, Beeson, Phillips, and Fraser. Cancer-incidence among California Seventh-day Adventists, 1976-1982. Am J Clin Nutr, 1994, 59 (suppl):1136S-42S.
24. E. Cheraskin, and others. J of Orthom Psych, 1978, 7:150-155.
25. Diana Schwarzbein and Nancy Deville. The Schwarzbein Principle (HCI Publications; Florida), 1999; Robert C. Atkins. Dr. Atkins' New Diet Revolution. (Avon Books; NY), 2002; Wolfgang Lutz. Life Without Bread (NTC/Contemporary Publishing; IL), 1999.