Women aged 65 and over who drink more than five cups of coffee a day are more likely to have low bone density, according to a new study.
Researchers at Flinders University in Australia tracked coffee and tea consumption and changes in bone density among 9,704 women aged 65 and over for about a decade, the New York Post reported.
When the researchers examined bone density at the upper thigh bone and the hip, women who drank more than five cups of coffee a day tended to show lower readings. Two to three cups a day, by contrast, showed no link to declining bone density.
Women who drank tea tended to have higher hip bone density. Ryan Liu, a co-author of the study, said catechins, which are abundant in tea, may help build bone and slow its breakdown.
On the caffeine in coffee, he said it can interfere with calcium absorption and bone metabolism, while adding that the effect may be small.
Lisa Young, an adjunct professor of nutrition at New York University, said moderate coffee consumption appears to be fine and that there is no need to switch to another drink for the sake of bone health. The surest way to protect bone health, she stressed, is to get enough calcium and vitamin D, stay physically active, and avoid smoking and excessive drinking.
Liu also said the findings do not mean people have to give up coffee, but that they suggest very heavy coffee consumption may be inadvisable for women who drink alcohol.
Caffeine is known to increase calcium excretion through urine and to hinder calcium absorption in the small intestine. Excessive caffeine intake lowers bone density and raises the likelihood of osteoporosis, a condition in which bones weaken to the point that even minor impacts can cause fractures. People who drink coffee frequently and feel dull aches in the lower back or other parts of the musculoskeletal system may want to consider a bone density test.
