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Abstract

BONDS and COLLEAGUES,  (1)Division of Cardiovascular Sciences, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland. (2)EMMES Corporation, Rockville, Maryland. (3)Department of Neurology, School of Medicine, University of Virginia, Charlottesville; (4)Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina; (5)Department of Family Medicine and Epidemiology, Division of Biology and Medicine, Alpert Medical School and the School of Public Health of Brown University, Providence, Rhode Island; (6)AstraZeneca LLP, Washington, DC; (7)Department of Epidemiology, University of Iowa, Iowa City8Department of Medicine, University of Iowa, Iowa City; (8)Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, Maryland set out to determine whether supplementing diet with long-chain ω-3 polyunsaturated fatty acids or with macular xanthophylls results in a reduced rate of cardiovascular disease (CVD).

Background

Dietary supplements have been proposed as a mechanism to improve health and prevent disease.

Methodology

The Cardiovascular Outcome Study (COS) was an ancillary study of the Age-Related Eye Disease Study 2 (AREDS2), a factorial-designed randomized clinical trial of 4203 participants recruited from 82 US academic and community ophthalmology clinics, who were followed up for a median of 4.8 years. Individuals were eligible to participate if they were between the ages of 50 and 85 years, had intermediate or advanced age-related macular degeneration in 1 eye, and were willing to be randomized. Participants with stable, existing CVD (>12 months since initial event) were eligible to participate. Participants, staff, and outcome assessors were masked to intervention. Interventions: Daily supplementation with long-chain ω-3 polyunsaturated fatty acids (350-mg docosahexaenoic acid [DHA] + 650-mg eicosapentaenoic acid [EPA]), macular xanthophylls (10-mg lutein + 2-mg zeaxanthin), combination of the two, or matching placebos. These treatments were added to background therapy of the AREDS vitamin and mineral formulation for macular degeneration. Main Outcomes And Measures: A composite outcome of myocardial infarction, stroke, and cardiovascular death with 4 pre-specified secondary combinations of the primary outcome with hospitalized heart failure, revascularization, or unstable angina.

Results

Study participants were primarily white, married, and highly educated, with a median age at baseline of 74 years. A total of 602 cardiovascular events were adjudicated, and 459 were found to meet 1 of the study definitions for a CVD outcome. In intention-to-treat analysis, no reduction in the risk of CVD or secondary CVD outcomes was seen for the DHA + EPA (primary outcome: hazard ratio [HR], 0.95; 95% CI, 0.78-1.17) or lutein + zeaxanthin (primary outcome: HR, 0.94; 95% CI, 0.77-1.15) groups. No differences in adverse events or serious adverse event were seen by treatment group. The sample size was sufficient to detect a 25% reduction in CVD events with 80% power.

Conclusion

Dietary supplementation of long-chain ω-3 polyunsaturated fatty acids or macular xanthophylls in addition to daily intake of minerals and vitamins did not reduce the risk of CVD in elderly participants with age-related macular degeneration.

References

Writing Group for the AREDS2 Research Group, Bonds DE(1), Harrington M(2), Worrall BB(3), Bertoni AG(4), Eaton CB(5), Hsia J(6), Robinson J(7), Clemons TE(2), Fine LJ(1) and Chew EY(8). Effect of long-chain ω-3 fatty acids and lutein + zeaxanthin supplements on cardiovascular outcomes: results of the Age-Related Eye Disease Study 2 (AREDS2)  randomized clinical trial. JAMA Intern Med. 174(5):763-71. doi: 10.1001/jamainternmed. 2014. 328. May 2014. Comment in BMJ.348:g2185. 2014     JAMA Intern Med. 174(5):771-2. May 2014.

 

AKUFFO and COLLEAGUES, (1)Macular Pigment Research Group, Department of Chemical and Life Sciences, Waterford Institute of Technology , Waterford , Ireland  studied the potential impact of macular pigment (MP) enrichment, following supplementation with 10 mg lutein (L), 2 mg zeaxanthin (Z) and 10 mg meso-zeaxanthin (MZ), on visual function in normal subjects (Trial  1) and in subjects with early age-related macular degeneration (AMD; Trial 2).

BACKGROUND: The Central Retinal Enrichment Supplementation Trials (CREST) aim to investigate the potential impact of macular pigment (MP) enrichment, following supplementation with a formulation containing 10 mg lutein (L), 2 mg zeaxanthin (Z) and 10 mg meso-zeaxanthin (MZ), on visual function in normal subjects (Trial  1) and in subjects with early age-related macular degeneration (AMD; Trial 2).

METHODOLOGY: CREST is a single centre, double-blind, randomized clinical trial. Trial 1 (12-month follow-up) subjects are randomly assigned to a formulation containing 10 mg L, 10 mg MZ and 2 mg Z (n = 60) or placebo (n = 60). Trial 2 (24-month follow-up) subjects are randomly assigned to a formulation containing 10 mg L, 10 mg MZ, 2 mg Z plus 500 mg vitamin C, 400 IU vitamin E, 25 mg zinc and 2 mg copper (Intervention A; n = 75) or 10 mg L and 2 mg Z plus 500 mg vitamin C, 400 IU vitamin E, 25 mg zinc and 2 mg copper (Intervention B; n = 75). Contrast sensitivity (CS) at 6 cycles per degree represents the primary outcome measure in each trial. Secondary outcomes include: CS at other spatial frequencies, MP, best-corrected visual acuity, glare disability, photo-stress recovery, light scatter, cognitive function, foveal architecture, serum carotenoid concentrations, and subjective visual function. For Trial 2, AMD morphology, reading speed and reading acuity are also being recorded.

CONCLUSIONS: CREST is the first study to investigate the impact of supplementation with all three macular carotenoids in the context of a large, double-blind, randomized clinical trial.

Akuffo KO(1), Beatty S, Stack J, Dennison J, O'Regan S, Meagher KA, Peto T and Nolan J. Central Retinal Enrichment Supplementation Trials (CREST): design and methodology of the CREST randomized controlled trials. Ophthalmic Epidemiol. 21(2):111-23. doi: 10.3109/09286586.2014.888085.  Apr 2014.