Omega-3 fatty acids, macular xanthophylls did not reduce CVD risk

Dietary supplementation of long-chain omega-3 fatty acids and macular xanthophylls did not reduce risk for CVD in elderly adults with age-related macular degeneration, according to new data from the AREDS2 study.

The research group for the AREDS2 study conducted the ancillary Cardiovascular Outcome Study to determine whether supplementation with long-chain omega-3 fatty acids and macular xanthophylls would reduce CVD risk in elderly patients with age-related macular degeneration.

The randomized clinical trial included 4,203 participants aged 50 to 85 years (median age at baseline, 74 years) who had intermediate or advanced age-related macular degeneration in one eye. Supplementation assignment was as follows: 1,012 received placebo; 1,044 received 10 mg lutein and 2 mg zeaxanthin; 1,068 received 350 mg docosahexaenoic acid (DHA) and 650 mg eicosapentaenoic acid (EPA); and 1,079 received lutein, zeaxanthin, DHA and EPA.

The primary outcome was a composite of CVD mortality, MI, stroke, unstable angina, coronary and carotid revascularization, hospitalization for congestive HF and resuscitated cardiac arrest. The four secondary outcomes included MI, stroke or CVD death; MI, stroke, CVD death or unstable angina; MI, stroke, CVD death or hospitalization for congestive HF; and MI, stroke, CVD death or revascularization.

Denise E. Bonds, MD, MPH, from the National Heart, Lung and Blood Institute, and colleagues recorded 602 CV events during the median follow-up period of 4.8 years. Of those, 459 events met one of the study definitions for a CVD outcome, according to the abstract.

Findings from an intent-to-treat analysis revealed no reduction in risk for CVD or any of the secondary outcomes for patients assigned DHA and EPA (HR=0.95; 95% CI, 0.78-1.17) or those assigned lutein and zeaxanthin (HR=0.94; 95% CI, 0.77-1.15).

Rates of adverse events and serious adverse events were also similar between the supplementation groups.

“Our results are consistent with a growing body of evidence from clinical trials that have found little CVD benefit from moderate levels of dietary supplementation,” the researchers wrote.

In a related editorial, Evangelos C. Rizos, MD, PhD, from University Hospital of Ioannia, and Evangelina E. Ntzani, MD, PhD, from University of Ioannia School of Medicine, Greece, said the present study and others demonstrate that “omega-3 supplementation with daily doses close to 1 g in patients with or without established CVD shows no clear considerable benefit.” The conduct of further randomized controlled trials seems unjustified, they wrote.

“The time is ripe for a meta-analysis of individual participant data where investigators will have the valuable opportunity to carry out time-to-event and subgroup analyses uniformly across all studies and draw conclusions on the postulated omega-3 varying effects based on the participants’ characteristics.”

For more information:

Bonds DE. JAMA Intern Med. 2014;doi:10.1001/jamainternmed.2014.328.

Rizos EC. JAMA Intern Med. 2014;doi:10.1001/jamainternmed.2013.13734.

Disclosure: Several researchers report financial ties with Amarin, Amgen, AstraZeneca, Daiichi Sankyo, Esperion, Genentech/Hoffman La Roche, GlaxoSmithKline and Merck. Rizos reports financial ties with Amgen, AstraZeneca/Bristol-Myers Squibb, Boehringer Ingelheim, Merck, Novo Nordisk, Plus Pharmaceutical and Vianex. Ntzani reports no relevant financial disclosures.