Fish Oil Supplement Fails to Reduce Hip Fractures

AUSTIN, Texas – Supplementing omega-3 fatty acids failed to protect mid-life and older healthy individuals from hip and other non-vertebral fractures, researchers reported here.

Among the participants in VITAL who were included in the omega-3 fatty acid portion of the study, there were 692 non-vertebral fractures among the 12,933 people taking marine-source omega-3 supplements and 671 non-vertebral fractures in the 12,938 people assigned to the placebo group (HR 1.03, 95% CI 0.92-1.13), reported Meryl LeBoff, MD, of Brigham & Women’s Hospital and Harvard Medical School in Boston.

In her oral presentation at the annual meeting of the American Society for Bone and Mineral Research, LeBoff also reported no difference in hip fractures after 5.3 years of follow-up (51 with supplements vs 55 with placebo, P=0.60).

The same was true for major osteoporotic fractures and wrist fractures (P=0.77 and P=0.25, respectively). Multiple fractures occurred in some participants, but the study did not include fractures of fingers, toes, skull, facial bones or periprosthetic, and pathological fractures.

Another portion of the factorial trial recently showed that supplemental vitamin D3 compared with placebo did not reduce fractures in midlife to older adults either.

“There is a high prevalence of osteoporotic fractures among older adults,” LeBoff noted, adding that about “22% of U.S. adults 60 years of age or older take supplemental omega-3 fatty acids. Although limited observational studies suggest an inverse association between intakes of omega-3 fatty acids and fracture risk, a recent randomized controlled trial found no effect of omega-3 fatty acid supplements on non-vertebral fractures.”

In performing the study, LeBoff and colleagues randomly assigned 6,547 people to receive 1 g per day of omega-3 fatty acids and assigned 6,538 individuals to receive placebo. The mean age of the participants was 67 years. About half of the subjects in the study were women. About 71% were non-Hispanic whites; about 20% were Black individuals. The mean body mass index was 28. About 10% of the participant had a history of fracture or frailty. About 27% had experienced a fall in the previous 12 months.

Participants were required to stop using omega-3 supplements and limit any non-study vitamin D supplements to 800 IU or less per day and limit calcium supplements to 1,200 mg/day or less. Fractures were reported annually by questionnaires or phone calls. Incident fractures were centrally adjudicated.

After 1 year of follow-up, those individuals who were tested for omega-3 fatty acid serum showed a 54.7% increase if they were given the supplemental dose, but the placebo group had less than a 2% increase, LeBoff reported. Study pill adherence was 87% at 2 years and 85.7% at 5 years, she reported.

In commenting on the study, co-moderator of the session, Rodrigo Valderrabano, MD, also of Harvard Medical School and Brigham and Women’s Hospital, pointed to “a number of questions raised in the study that require further investigation.”

The study hinted that omega-3 fatty acid intake might be a problem for men and for people with low body mass index but might benefit those with a higher body mass index, Valderrabano told MedPage Today. But, he noted, it was hard to make much sense of those findings without further research.

“At this point, there does not seem to be an advantage to using omega-3 fatty acid supplements to prevent fractures in this population,” he said. He suggested that there might be other groups that could benefit, but further research would be required to determine what that population would be. Valderrabano was not involved in the VITAL study.