This is part of our ongoing The Best Kept Secrets to Healthy Aging spotlight. Each week, we will be posting some of the great information that’s packed into our book, The Best Kept Secrets to Healthy Aging.
Tips for Better Bone Building, Part 9: Protein
A myth that still circulates in the world of nutrition is that eating large amounts of lean protein will increase calcium loss through the urine and predispose to osteoporosis. This has been proven to be a misconception and is just wrong. For example, when middle-aged men and women with a long history of fearful low-protein diets (providing less than 15% of total calories as protein) were fed either placebo or 55 g/day of a high quality animal meat protein in a study published recently in the Journal of Endocrinology and Metabolism, the normalization of protein intake had no effect on urinary excretion of calcium but decreased bone resorption and increased the secretion of the cytokine, insulin-like growth factor-1 (IGF-1).15 Because a major function of IGF-1 in adults is to stimulate bone formation, the combination of no effect on calcium loss, decreased bone resorption and stimulation of bone formation substantiate the conclusion that ensuring adequate healthy protein intake is truly beneficial to bone health. Of course, adequate protein intake is also beneficial for immune health, healthy blood sugar balance, and a number of other physiological effects.
This conclusion finds additional support in the results of a study published recently in the Annals of Surgery.16 In this study, injections of human growth hormone were used to stimulate IGF-1 production and secretion into the blood. Increased serum IGF-1 concentrations were accompanied by increased total body bone mineral content. Because IGF-1 independently stimulates bone formation, this result indicates that any means that increases IGF-1 production, including increasing the daily intake of high-quality low-fat protein, will likely enhance bone health.
Next Best Kept Secrets to Healthy Aging topic:
Tips for Better Bone Building, Part 10: Soy Protein Isoflavones
15. Dawson-Hughes B, Harris SS, Rasmussen H, Song L, Dallal GE. Effect of dietary protein supplements on calcium excretion in healthy older men and women. J Clin Endocrinol Metab 2004;89:1169-1173.
16. Przkora R, Herndon DN, Suman OE, Jeschke MG, Meyer WJ, Chinkes DL, Mlcak RP, Huang T, Barrow RE. Beneficial effects of extended growth hormone treatment after hospital discharge in pediatric burn patients. Ann Surg 2006;243:796-801.