Total mortality risk in relation to use of less-common dietary supplements

Abstract

Dietary supplement use is common in older US adults; however, data on health risks and benefits are lacking for a number of supplements. We evaluated whether 10-y average intakes of 13 vitamin and mineral supplements and glucosamine, chondroitin, saw palmetto, Ginko biloba, garlic, fish-oil, and fiber supplements were associated with total mortality. We conducted a prospective cohort study of Washington State residents aged 50-76 y during 2000-2002. Participants (n = 77,719) were followed for mortality for an average of 5 y. A total of 3577 deaths occurred during 387,801 person-years of follow-up. None of the vitamin or mineral 10-y average intakes were associated with total mortality. Among the nonvitamin-nonmineral supplements, only glucosamine and chondroitin were associated with total mortality. The hazard ratio (HR) when persons with a high intake of supplements (> or =4 d/wk for > or =3 y) were compared with nonusers was 0.83 (95% CI: 0.72, 0.97; P for trend = 0.009) for glucosamine and 0.83 (95% CI: 0.69, 1.00; P for trend = 0.011) for chondroitin. There was also a suggestion of a decreased risk of total mortality associated with a high intake of fish-oil supplements (HR: 0.83; 95% CI: 0.70, 1.00), but the test for trend was not statistically significant. For most of the supplements we examined, there was no association with total mortality. Use of glucosamine and use of chondroitin were each associated with decreased total mortality.