CRN weighs in on AREDS2, heart health

CRN weighs in on AREDS2, heart health

MacKay: "It's unfortunate that the race to sensationalize the less beneficial outcomes for certain subgroups in this study may overshadow the real benefits of long-term omega-3 use."

In response to a study published March 17, “Effect of Long-Chain Omega-3 Fatty Acids and Lutein + Zeaxanthin Supplements on Cardiovascular Outcomes—AREDS2,” in JAMA Internal Medicine, the Council for Responsible Nutrition (CRN), the leading trade association representing the dietary supplement industry, issued the following statement:

Statement by Duffy MacKay, ND, senior vice president, scientific and regulatory affairs, CRN: 

“Omega-3 fatty acids, found in fish and in dietary supplements, promote better health by helping to reduce the long-term risks of cardiovascular disease; this study demonstrates exactly these positive results with certain populations in the study. It’s unfortunate that the race to sensationalize the less beneficial outcomes for other subgroups may overshadow the real benefits of long-term usage of omega-3s. For example, the researchers found a significant protective effect against cardiovascular disease for those taking omega-3 supplements who had no previous history of hypertension. They also identified a numerical trend, if not a statistically significant one, toward the benefit of omega-3 supplementation both among those with no history of cardiovascular disease or no elevated cholesterol levels. These benefits underscore the value of omega-3s in combination with other healthy habits to help avoid cardiovascular disease among otherwise healthy populations.

“This was a well-designed, well-executed study, but like all studies, it is not without limitations, and the researchers were forthcoming in noting those limitations. They acknowledged that ‘…the timing of the administration of the supplements may have been too late to affect outcomes. The AREDS2 participants were older, and many had existing CVD or elevated risk for CVD.’ And, they advised, ‘We cannot exclude a beneficial effect from starting supplementation earlier in life.’

“We also have to consider realistic expectations for supplements. The omega-3s and lutein + zeaxanthin interventions were layered on top of other nutrients that were given to everyone in the study population, so finding added benefits in an already well-nourished group becomes that much more difficult. Additionally, the researchers designed what could be considered drug-like criteria for the primary outcome. In other words, the researchers acknowledged that given the sample size they started with, they would have had to see a 25 percent risk reduction to identify the results as beneficial. This kind of statistical outcome, while realistic for pharmaceutical interventions that provide powerful and immediate results—potentially accompanied by powerful risks—may not be appropriate for studying nutrients. But that doesn’t discount more subtle benefits for supplements, especially given the lower risks and costs. If you’re one of the people who does experience a benefit, then it’s worth considering this option. 

“With regard to lutein and zeaxanthin, people are taking those supplements for eye health, not to prevent or treat cardiovascular disease, so the results were not surprising—lutein and zeaxanthin are not cure-alls. But if we look at the AREDS2 study itself [released last May], it demonstrated positive and statistically significant findings related to eye health for many individuals not already getting enough lutein and zeaxanthin in their diet. By adding those supplements, the study found a decrease of advanced age-related macular degeneration progression, a reduction in risk for severe cataracts, and a reduction of progression to cataract surgery.

“For those who choose to call each study the final word, or a reason to close the door on vitamins, consider this: we all wish science produced black-and-white answers, so we could have a non-negotiable roadmap to good health; the fact is science doesn’t work that way—there are always detours. Reducing the risk of future disease involves a constellation of behaviors and interventions. Consumers deserve options, and dietary supplements are one piece of the puzzle—not a panacea—for finding the pathway to healthier lives.”



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