Nutraceutical: Omega 3s

Indication: Total & Cause-Specific Mortality

Source: Annals of Internal Medicine, Apr. 2, 2013; 158(7):515-525

Research: Long-chain omega 3 polyunsaturated fatty acids (PUFAs), including EPA, DPA and DHA have been shown to reduce cardiovascular risk, but effects on cause-specific and total mortality and potential dose-responses remain controversial. Researchers investigated associations of plasma phospholipid EPA, DPA, DHA and total PUFA levels with total and cause-specific mortality among healthy older adults not receiving supplements. This prospective cohort study funded by the National Institutes of Health involved 2,692 U.S. adults aged 74 years (±5 years) without prevalent coronary heart disease (CHD), stroke or heart failure at baseline. Phospholipid fatty acid levels and cardiovascular risk factors were measured in 1992. Relationships with total and cause-specific mortality and incident fatal or non-fatal CHD and stroke through 2008 were assessed.

Results: During 30,829 person-years, 1,625 deaths (including 570 cardiovascular deaths), 359 fatal and 371 non-fatal CHD events, and 130 fatal and 276 non-fatal strokes occurred. After adjustment, higher plasma levels of omega 3 PUFA biomarkers were associated with lower total mortality, with extreme-quintile hazard ratios of 0.83 for EPA (95% CI, 0.71 to 0.98; P for trend = 0.005), 0.77 for DPA (CI, 0.66 to 0.90; P for trend = 0.008), 0.80 for DHA (CI, 0.67 to 0.94; P for trend = 0.006), and 0.73 for total omega 3 PUFAs (CI, 0.61 to 0.86; P for trend < 0.001). Lower risk was largely attributable to fewer cardiovascular than non-cardiovascular deaths. Individuals in the highest quintile of phospholipid PUFA level lived an average of 2.22 more years (CI, 0.75 to 3.13 years) after age 65 years than those in the lowest quintile.

Researchers noted that temporal changes in fatty acid levels and misclassification of causes of death may have resulted in underestimated associations, and unmeasured or imperfectly measured covariates may have caused residual confounding. Overall, researchers concluded that higher circulating individual and total omega 3 PUFA levels are associated with lower total mortality, especially CHD death, in older adults.