Drinking more milk as a teenager does not lower risk of hip fracture later

Drinking more milk as a teenager apparently does not lower the risk of hip fracture as an older adult and instead appears to increase that risk for men, according to a study published by JAMA Pediatrics, a JAMA Network publication.

While drinking milk during adolescence is recommended to achieve peak bone mass, milk's role in hip fractures later in life has not been established. Drinking more milk is associated with attaining greater height, which is a risk factor for hip fracture, according to the study background.

Diane Feskanich, Sc.D., of Brigham and Women's Hospital and Harvard University, Boston, and colleagues examined the association between remembered teenage milk consumption and risk of hip fracture at older ages in a study of more than 96,000 men and women with a follow-up of more than 22 years. During the follow-up, 1,226 hip fractures were reported by women and 490 by men.

Study findings indicate teenage milk consumption (between the ages of 13-18 years) was associated with an increased risk of hip fractures in men, with each additional glass of milk per day as a teenager associated with a 9 percent higher risk. Teenage milk consumption was not associated with hip fractures in women. The association between drinking milk and hip fractures in men was partially influenced by height, according to the study

"We did not see an increased risk of hip fracture with teenage milk consumption in women as we did in men. One explanation may be the competing benefit of an increase in bone mass with an adverse effect of greater height. Women are at higher risk for osteoporosis than men, hence the benefit of greater bone mass balanced the increased risk related to height," the authors comment.

Cheese intake during teenage years was not associated with the risk of hip fracture in either men or women.

Diane Feskanich, an assistant professor at Harvard Medical School in Boston, and her team tested the assumption by looking at hip fractures among more than 61,000 women and 35,000 men over 22 years.

"We questioned the belief that drinking more milk in earlier life would help to avoid these fractures in older adults," Feskanich said in an interview.

In Monday's issue of the journal JAMA Pediatrics, Feskanich and her co-authors said milk consumption during teenage years was not associated with a lower risk of hip fracture in the group of older adults they studied.

The researchers analyzed findings from white participants from the Nurses' Health Study and Health Professional Followup Study.

Health Canada recommends 1,300 milligrams of calcium for children aged nine to 18.

"It does make you stop and ponder and want to see better evidence for our dietary recommendations," Feskanich said of the study's findings.

The authors suggest that further research needs to be done to examine the roles of early milk consumption and height in preventing hip fractures in older adults.