Studies Provide Little Support for Guidelines on Dietary Fats and Supplements

By Larry Husten

Two new studies demonstrate the shaky underpinnings of guidelines that encourage the intake of omega-3 fatty acids.

The first, a large meta-analysis in the Annals of Internal Medicine, examined dietary fatty acid consumption, fatty acid biomarkers, and fatty acid supplements. Among the chief findings:

• Omega-3 and omega-6 fatty acids: There were trends for modest benefits associated with dietary intake or supplements, but these did not achieve statistical significance.

• Saturated fatty acids: There was no discernible effect of total saturated fat as measured by either dietary intake or circulating biomarkers.

• Monounsaturated fatty acids: No effect was found.

• Trans dietary fats: A harmful effect was confirmed.

In the second study, published in JAMA Internal Medicine, 4200 patients with age-related macular degeneration were randomized to omega-3 fatty acids; lutein/zeaxanthin (carotenoids found in the eye); both; or placebo. After roughly 5 years, there was no significant reduction in cardiovascular outcomes in the treatment groups.

Commentators say it's now clear that omega-3 supplements "with daily doses close to 1 g in patients with or without established CVD shows no clear, considerable benefit." They conclude that for now, omega-3s should be prescribed only for patients with severe hypertriglyceridemia, "an extreme minority of the general population."

Adapted from CardioExchange