Protein and Osteoporosis

Bone mineral density (BMD) was measured at the lumbar spine and femoral neck in 258 postmenopausal vegetarian Taiwanese Buddhist nuns. The results indicated a significant positive correlation between energy intake from protein and lumbar spine BMD. Other nutrients, including calcium and energy intake from non-protein sources, did not correlate significantly with BMD...These results suggest that protein deficiency may promote the development of osteoporosis and that long-term female vegans may be at increased risk of developing bone loss.
Chiu JF, et al, Long-term Vegetarian Diet and Bone Mineral Density in Postmenopausal Taiwanese Women,
Cacif Tissue Int 1997;60:245-249

COMMENT:
Bones and cartilage are heavily mineralized collagen which is the most abundant protein in the body. Minerals alone will not build strong bones and cartilage. Sufficient ingestion of proteins with methionine, and a healthy ability to digest and transform it to body protein, are necessary to build collagen.

Sulfates are particularly valuable for bone and cartilage integrity and as well for hundreds of sulfur compounds in the body, such as chondroitin sulfate and a bile salt.  

Sulfate is primarily produced from the only sulfur-containing amino acids in our diets: methionine and cysteine. Methionine is an essential amino acid, it must be ingested and it cannot be synthesized. Cysteine is essential in some conditions.

Of the top ten foods highest in methionine, Brazil nuts, beans and soy are the only foods suitable for a vegan. However, the availability of methionine from beans and soy is in question. The other foods in the top ten include meats, fish, shellfish, dairy and eggs.

Lack of sulfates will result in brittle bones and cartilage, which manifest respectively as osteoporosis and osteoarthritis.