Nutrition,lifestyle and genetics may all contribute to the decrease in bone mineral density (BMD) that comes with aging and leads to osteoporosis, a major cause of fractures in the elderly. Previous research implicated cafeine in increased risk for hip fracture and poor clacium retention.
As part of a larger long-term study of osteoporosis, Rapuri et al. Compared the bone mineral density of women in high and low categories of caffeine consumption to examine th interaction between caffeine intake, genetic type, and osteoporosis.They found that women with high caffeine intakes had significantly higher rates of bone loss at the spine, and that women who were homozygous for a mutation in the vitamin D receptor (VDR) gene were at greater risk for caffeine-related bone loss.
Women in the high cafeeine category with the tt genotype lost bone density over 3 years, compared with no change in bone desity in women in the low caffeine group.Though the number of women with the tt genotype was found to be relatively small (six in the low caffeine group and five in the high caffeine group), these findings identify caffeine as a dietary factor, which can alter one's genetic predisposition toward osteoporosis.
An editorial by Massey stresses that moderate caffeine ingestion-less than 16 ounces of brewed coffee per day or 32 ounces of brewed tea-is not associated with increased bone loss.Until it is practical to determine each person's VDR genotype, physicians should recommend both adequate dietary calcium and moderate caffeine comsumption for their elderly patients.