Plant-Based Proteins Necessary for Healthy Bones: Study

Study assesses the relationship between prevalence of osteoporosis and proportion of daily protein intake: Kim J, Kim B, Lee H, Choi H, Won C. The relationship between prevalence of osteoporosis and proportion of daily protein intake. Korean J Fam Med. 2013;34(1):43-48.

“Higher animal protein levels are associated with osteoporosis in this study and others. Phyto-based proteins, polyphenols and other compounds found in fruits and vegetables, like soybeans, wasabi, Satsuma oranges, sargassum algae and others, are associated with stimulating osteoblastic activity, decreasing osteoclastic activity of the bones, and could be preventive of osteoporosis.”

This current study is helpful in recognizing that protein is necessary for healthy bones, but not too much animal source proteins. It has been seen before that the possibility of low-level metabolic acidosis, which is influenced by increased animal protein intake and low plant based diet could be a big factor with aging and osteoporosis. With a high protein diet, the acids produced might be buffered with calcium from the bones. There are other postulated theories about this as well involving growth factor affecting calcium and phosphate metabolism. The exact amounts of protein needed in the diet for healthy bones may vary based on ethnicity (Asian vs. Caucasian), calcium intake and other risk factors and concomitant diseases.

The prevention of osteoporosis is very important as life expectancies have increased, and the incidence of bone fractures from osteoporosis has increased with aging populations. There is some indication as well that increased calcium intake along with higher protein diets may protect the bones from excess bone loss from acid leaching calcium from protein metabolism to be neutralized and excreted by the body.  People with lower protein diets were found to have lower BMD in this study and others. At least in the Korean population a high enough protein level is important for making healthy bones. As to what this level might be, it remains a question. In two other studies cited in this study, a US study found that women who had > 95 grams of protein per day had more risk for forearm fractures than those whose level was <68 grams/day. The other, a Norwegian study, found that lower calcium and high protein intake levels were associated with higher levels of fracture. The question of adequate protein and calcium levels in osteoporosis is worthy of further research. From this study, it does appear that an adequate  level of plant-dominated protein is necessary for healthy bone formation.