Reading Between the Lines of the AREDS2 Study

by Harry B. Rice

Earlier this month the Age-Related Eye Disease Study 2 (AREDS2) was published in the Journal of the American Medical Association (JAMA).

The study is a follow-up to AREDS, demonstrating that oral supplementation with a specific formulation of antioxidant vitamins C and E, beta-carotene, copper and zinc reduces the risk of progression to advanced age-related macular degeneration (AMD). The objective of AREDS2 was to determine whether adding lutein + zeaxanthin, docosahexaenoic acid (DHA) + eicosapentaenoic acid (EPA), or both to variations of the AREDS formulation further decreases the risk of developing advanced AMD and to evaluate the effect of eliminating beta carotene, lowering zinc doses, or both on AMD.

One reason the study made news is because it did not find that lutein + zeaxanthin, DHA + EPA, or both further reduced the risk of progression to advanced AMD.

Despite the outcome of AMD progression not being halted in the present study, this doesnt mean that EPA + DHA arent beneficial for AMD. Keep in mind that this was a secondary prevention study, where all subjects had intermediate age-related macular degeneration (AMD) in at least one eye. While past research suggests a role for EPA + DHA in decreasing the risk of developing AMD, the present research does not address this issue.

Also, there was no true placebo group, rather an active placebo group. More specifically, all subjects received some variation of the oral supplement formula used in the original AREDS, which had already demonstrated that use of high-dose antioxidant and zinc supplements reduced progression of intermediate to late AMD. Because this treatment was shown to slow the progression of AMD, it would be considered unethical to deprive any of the study participants access to this regimen. However, this does make it much more difficult to demonstrate a benefit of any of the treatments.

As with all research questions, there are a variety of factors that need to be considered. For example, it is important to note that more research is being reported on nutritional interactions with genetic factors. Given that genetics appear to explain a large proportion of the variability in risk of AMD, future research should consider subject recruitment based on certain known genetic risk factors. In such population subgroups, EPA + DHA may prove to be beneficial in individuals with intermediate to advanced AMD.

Lastly, given the importance of DHA to eye health, it is also possible that the amount supplemented may have been too low to have an effect. While EPA + DHA did not attenuate the progression from intermediate to advanced AMD, its possible that earlier stages of AMD may be more responsive to treatment or that EPA + DHA could have prevented the onset of macular degeneration in the first place. Prevention is always more effective than treatment!

Harry B. Rice is the vice president of regulatory and scientific affairs for the Global Organization for EPA and DHA Omega-3s ( GOED ). He has worked in the ingredient, dietary supplement, functional food and consumer packaged goods industries for more than a decade. Among his responsibilities for GOED are monitoring and reporting on regulatory issues, spearheading efforts on complex issues, and providing scientific analysis of the growing body of scientific literature. In addition, Rice manages the scientific and regulatory committees. Prior to joining GOED and UNPA, he spent more than six years at Cargill Inc., involved in the development and execution of global regulatory and scientific strategies for a wide range of functional ingredients. Rice earned a master's and doctorate in nutrition from Pennsylvania State University and a bachelor's degree in dietetics from Miami University (Ohio).