Tips for Better Bone Building, Part 10: Soy Protein Isoflavones

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.

Today’s topic:
Tips for Better Bone Building, Part 10: Soy Protein Isoflavones

Soy protein contains a set of phytochemicals called isoflavones. These phytonutrients are absorbed into the human blood stream and circulate to a variety of tissues where they interact with the processes regulating cell functions. One area of isoflavone biology that has received a great deal of attention is the support of bone health. Studies consistently show a beneficial effect of soy isoflavone consumption on human bone. The results of a hallmark randomized, placebo-controlled study demonstrated that several months of daily supplementation with 90 mg of soy isoflavones facilitated an increase in the bone mineral content and bone mineral density of the spine in postmenopausal women.17 In contrast, only 56 mg daily was not effective. Another randomized, placebo-controlled study showed that daily consumption of 80 mg of soy isoflavones for 6 months supported the density of vertebral bone in perimenopausal women.18 In confirmation of previous studies, two studies published recently demonstrated that less than 80 mg of soy isoflavones daily is ineffective in promoting bone health in postmenopausal women.19,20

Next Best Kept Secrets to Healthy Aging topic:
Tips for Better Bone Building, Part 11:  Ipriflavone

References:
17. Potter SM, Baum JA, Teng H, Stillman RJ, Shay NF, Erdman JW Jr. Soy protein and isoflavones: Their effects on blood lipids and bone density in postmenopausal women. Am J Clin Nutr 1998;68(Suppl.):1375S-1379S.
18. Alekel DL, Germain AS, Peterson CT, Hanson KB, Stewart JW, Toda T. Isoflavone-rich soy protein isolate attenuates bone loss in the lumbar spine of perimenopausal women. Am J Clin Nutr 2000;72:844-852.
19. Roughead ZK, Hunt JR, Johnson LK, Badger TM, Lykken GI. Controlled substitution of soy protein for meat protein: Effects on calcium retention, bone, and cardiovascular health indices in postmenopausal women. J Clin Endocrinol Metab 2005;90:181-189.
20. Arjmandi BH, Lucas EA, Khalil DA, Devareddy L, Smith BJ, McDonald J, Arquitt AB, Payton ME, Mason C. One year soy protein supplementation has positive effects on bone formation markers but not bone density in postmenopausal women. Nutr J 2005;4:8. doi:10.1186/1475-2891-4-8 (http://www.nutritionj.com/content/4/1/8).