Wheat bran fiber supplementation and bone loss among older people.

OBJECTIVE: The purpose of this study was to investigate the effect of wheat bran fiber (WBF) supplementation on bone loss in older people. METHODS: Two hundred thirty-seven men and women ages 40 to 80 y were included in this study. They constituted a subgroup of participants from a 3-y WBF intervention trial for preventing recurrence of colorectal adenomas. These participants were randomized into a high (13.5 g/d) or a low (2 g/d) WBF supplementation group. Bone mineral density at the forearm was measured by single photon absorptiometry at baseline and yearly during the intervention to monitor possible toxic effects of fiber supplementation on bone metabolism. RESULTS: Baseline characteristics of this subgroup of participants from the WBF trial were similar between the high and low supplementation groups. The annual amounts of bone loss at the radial third site were -0.017 +/- 0.018 g/cm2 and -0.013 +/- 0.021 g/cm2, respectively, for the low and high WBF groups; and the annual bone losses at the ultra-distal site were was -0.005 +/- 0.020 g/cm2 and -0.006 +/- 0.027 g/cm2, respectively, for the low and high WBF groups. After controlling for confounding factors, we found no significant differences in bone loss between groups (P > 0.05). CONCLUSION: WBF supplementation at the level given in this study may not have a significant effect on bone loss among older people.

Sex differences in bone loss--an evolutionary perspective on a clinical problem.

The dramatic increase in the world's population that has occurred over the past 100 years has come largely through reductions in death due to infectious disease. An epidemiologic transition to a preponderance of deaths due to degenerative conditions such as cardiovascular disease and cancer is occurring in the developing countries as well as in the industrialized ones. In the industrialized countries, demographic profiles now reflect the increased life expectancies of both sexes. However, female life expectancies exceed male by six or more years. Further change in mortality patterns will accompany success in the reduction of the number of mortalities attributable to such degenerative conditions as cardiovascular disease and cancer. In the 21st century, conditions associated with sensescence will be of increasing concern. Adaptive strategies that enhanced reproductive success throughout most of human evolution may now prove detrimental to human health as average life expectancies reach unprecedented length. In this environment, differences in the survival mechanisms deployed by males as opposed to females will become increasingly important.