These are related in that meat and saturated fat consumption go hand in hand. One only needs to look at the scientific research to show that Dr. Byrnes' position is scientifically untenable. I'll cite some of the research in the body of this article so there is no mistaking it.
Regarding meat consumption and osteoporosis, it is simply a matter of looking at the data from present day studies to show the increased risk from a high animal protein diet. Here are some quotes from the literature.
"Elderly women with a high dietary ratio of animal to vegetable protein intake have more rapid femoral neck bone loss and a greater risk of hip fracture than do those with a low ratio. This suggests that an increase in vegetable protein intake and a decrease in animal protein intake may decrease bone loss and the risk of hip fracture. This possibility should be confirmed in other prospective studies and tested in a randomized trial."
Sellmeyer DE, et al., A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. Study of Osteoporotic Fractures Research Group. Am J Clin Nutr 2001 Jan;73(1):118-22
" ... adverse dietary practices for BD [bone density] included intakes of protein and phosphorus greater than recommended amounts."
Metz JA, et al., Intakes of calcium, phosphorus, and protein, and physical-activity level are related to radial bone mass in young adult women. Am J Clin Nutr 1993 Oct;58(4):537-42.
"When female fracture rates derived from 34 published studies in 16 countries were regressed against estimates of dietary animal protein, a strong, positive association was found."
Abelow BJ, et al., Cross-cultural association between dietary animal protein and hip fracture: a hypothesis. Calcif Tissue Int 1992 Jan;50(1):14-8
On the other hand, high consumption of soy products has the opposite effect.
"High consumption of soy products is associated with increased bone mass in postmenopausal women and might be useful for preventing hypoestrogenic effects."
Somekawa Y, et al., Soy intake related to menopausal symptoms, serum lipids, and bone mineral density in postmenopausal Japanese women. Obstet Gynecol 2001 Jan;97(1):109-15.
While Dr. Byrnes maintains that "The belief that animal protein contributes to heart disease is a popular one that has no foundation in nutritional science," he is ignoring the science. A study by Dudrick using an animal model clearly showed regression of atherosclerosis and reduction of cholesterol levels when intravenous feeding of different amino acids similar to vegetable protein, and progression with amino acids similar to meat protein.
Dudrick SJ. Regression of atherosclerosis by the intravenous infusion of specific biochemical nutrient substrates in animals and humans. Ann Surg 1987 Sep;206(3):296-315.
Dr Byrnes says that heart disease is low in France where meat consumption is high. However, the number one killer in France is heart disease, and the rate of heart disease there is higher than in eastern Mediterranean peoples who have a much lower meat consumption, but high vegetable, fruit, bean, and grain diets. The rate of heart disease in Japan and China is far lower than either of these regions, and their meat consumption is far lower.
A study of Seventh Day Adventists makes the following conclusion: "Multivariate analyses showed significant associations between beef consumption and fatal ischemic heart disease (IHD) in men [relative risk (RR) = 2.31 for subjects who ate beef >/=3 times/wk compared with vegetarians]." Fraser GE, Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-hispanic white california seventh-day adventists. Am J Clin Nutr 1999 Sep;70(3 Suppl):532S-8S.
A study from Crete showed "the diet with the greatest life expectancy in the western world is that of Crete, largely vegetarian with a high intake of alpha-linolenic acid." Renaud SC, Dietary management of cardiovascular diseases. Prostaglandins Leukot Essent Fatty Acids 1997 Oct;57(4-5):423-7. But this is still higher than the rates of heart disease in Okinawa with a largely vegetarian diet that is also high in soy products.
Regarding kidney stones, Dr. Byrnes again is ignoring the data in favor of theory. For example, in a study from Texas, an " ... animal protein diet, when its electrolyte composition and quantity of protein were kept the same as for the vegetarian diet, conferred an increased risk for uric acid stones ... " Breslau NA, et al., Relationship of animal protein-rich diet to kidney stone formation and calcium metabolism. J Clin Endocrinol Metab 1988 Jan;66(1):140-6.
And this quote from another article "High protein intake is an accepted risk factor for renal stone disease," is rather unequivocal, and they conclude that for one third of idiopathic stone formers, meat is clearly a risk factor. Nguyen QV, Sensitivity to meat protein intake and hyperoxaluria in idiopathic calcium stone formers. Kidney Int 2001 Jun;59(6):2273-81.
I have already reported a few of the studies showing higher cancer rates among meat eaters compared to vegetarians, and I see no need to repeat them here. I could list hundreds more.
Recommendation of a high-animal-protein diet with so many clear risks, based on theoretical or historical arguments, is clearly putting millions of people at risk with little scientific justification. This does not mean that the science is absolute on the issue, as science is never so clearly final. We make decisions on the best evidence to date, and never are in the luxurious position of having absolute scientific proof. The risks of a high meat diet are clear in the science. Whether the reader wants to accept those risks and wait for more definitive studies is a personal decision.
Michael Janson, MD
Michael Janson, M.D., is past-president of both the American College for Advancement in Medicine and the American Preventive Medical Association. He founded one of the first complementary/alternative medical practices in New England in 1976. He has lectured widely on the subjects of nutrition, complementary/alternative medicine, vitamin supplements, and chelation therapy. He has been on a mostly vegetarian diet since 1975.
Dr. Janson is the author of: The Vitamin Revolution in Health Care; Chelation Therapy and Your Health; All About Saw Palmetto and Prostate Health; and Dr. Janson's New Vitamin Revolution (Penguin-Putnam-Avery, 2000). He has written articles for many health magazines and newspapers, and he is a regular radio-show guest. He publishes a monthly newsletter, Dr. Michael Janson's Healthy Living, available free by Email (newsletter@drjanson.com) by placing "text newsletter" in the subject line. His website is www.drjanson.com.
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