Impact of Vegetable Protein on Calcium and Bone Metabolism

Karl Insogna, M.D., Professor of Internal Medicine (Endocrinology).

Women are four times more likely than men to suffer from osteoporosis, a condition in which bones become fragile and can break due to loss of mineral and protein content, particularly calcium. Osteoporosis is especially common in older women, and half of all women over the age of 50 with osteoporosis will have a fracture due to the porous bones that characterize this condition. Dr. Insogna is uncovering the role of protein in our diets and the long-term effects on skeletal health. Implications of this work include revised dietary guidelines on protein and calcium intake for bone health. 

Highlighted Study Findings

Diet is a crucial source of necessary protein intake, and appropriate diet may reduce the need for supplements and medications to prevent osteoporosis. One source of protein that has gained popularity is soy.  In fact, many young women have adopted soy protein (vegan) diets and 25% of postmenopausal women consume less than the recommended daily requirement of protein. In this study, Dr. Insogna’s laboratory showed that diets based exclusively on soy (vegetable) protein, rather than animal protein, may actually reduce calcium absorption. The basis for this is being studied further, but this finding raises the question of how to use soy and whether animal protein is required to maintain bone health. These results indicated that the type of protein in our diets has important long-term consequences for skeletal health, and suggests that a diet without (or low in) animal protein may not provide the necessary nutrients to maintain healthy bone.