Mainstream treatment for post menopausal bone loss comprises of calcium, vitamin D and hormone replacement therapy. However, research is growing that diet has a far greater influence of bone health than previously thought. Older studies generally used less reliable methods for the measurement of bone mass, such as single-photon absorptiometry, and there was less reliable recording of diet via the use of 24 hour diet recall. Most modern studies use duel-energy X-ray absorptiometry and the frequent food questionnaire, which are thought to be more reliable. Some older studies also did not adjust dietary intake for the energy content of the food. Using more modern techniques has allowed researchers to produce more detailed assessments of the effects of various foods on bone health. The picture is growing that high levels of organic potassium salts and low levels of protein are beneficial to bone health because this alkalises the blood pH.
A longitudinal study1 followed 891 women between the ages of 45 to 55 and 50 to 59 years and assessed the bone mineral density of the lumbar spine and femoral neck using dual-energy X-ray absorptiometry. Associations were made to dietary factors at baseline and at the 5 year follow up by the use of a frequent food questionnaire. The results showed that high intakes of calcium were associated with a reduced loss of bone mineral density from the femoral head, and modest intakes of alcohol were associated with a reduced loss of lumbar spine density. Greater loss of bone mineral density was associated with high intakes of polyunsaturated and monounsaturated fatty acids but no changes were found for total or saturated fats. Vitamin E was also negatively associated with bone mineral loss, but only dietary sources, which are usually associated with polyunsaturated fats.
A group of women who had not yet reached the menopause and who were not receiving hormone replacement therapy were examine separately because hormone replacement therapy can be a confounding variable. In this group calcium, phosphorus, potassium, magnesium, folic acid and vitamin C were all associated with greater bone mineral density. Total fat, polyunsaturated fat and monounsaturated fat were all associated with decreased bone mineral density. That higher fat intakes are associated with greater bone mineral loss may be because dietary fat can form soaps with certain minerals that decreases their absorption. The fact that saturated fats were not associated with lower bone densities may reflect the fact that milk and milk products are sources of saturated fats as well as good sources of calcium. As with previous studies, fruits and vegetables were associated with increased bone mineral densities, probably on account of their high potassium contents.
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