Omega-3 Lowers AMD Risk: Strongest Evidence to Date

Good Habits + Omega-3: A Winning Strategy

Staying physically active, eating well and not smoking can improve your chances of avoiding age-related macular degeneration (AMD), according to study findings reported in the previous issue of Staying Healthy.

In terms of eating habits, that study found benefit for people who ate fruits and vegetables (sources of eye-healthy lutein and polyphenols), and whole grains, which have less impact on blood sugar fluctuations. Also beneficial was avoiding excessive salt and added sugar, using low fat dairy, and keeping saturated fats to a minimum.

While the researchers didn’t look specifically at intake of fatty acids from fish, many other studies have. And the results have been pretty consistent: getting enough omega-3 fats can also up your odds of keeping the macula healthy as we age.

Adding to that evidence is new research from Harvard showing that regular omega-3 intake can significantly lower the risk of AMD by up to 45%. It’s the strongest evidence to date, according to the investigators, that the omega-3s may actually help prevent AMD.

Investigators Follow Women with no AMD

The Harvard research team analyzed information on eating habits collected from over 38,000 women who participated in the Women’s Health Study. None of the women, who were 55 years of age on average, were diagnosed with AMD at the beginning of the study. After 10 years of follow-up, 235 of the participants had developed signs of the disease, most in the early stages of AMD development.

The investigators found that women who regularly consumed DHA, EPA and fish had a 35% to 45% lower risk of visually significant AMD. Looking at fish intake, one or more servings per week was associated with a 42% reduction in risk compared to one or fewer servings per month.

The team also observed that the apparent benefit of EPA and DHA was more pronounced in women who consumed higher levels of omega-6 intake. This suggests that both the level of omega-3 fats and its ratio to omega-6 fats is important in determining the risk of AMD.

How Might Omega-3 Help Protect the Macula?

There are many ways that DHA and EPA might act to decrease AMD risk. For example, both DHA and EPA influence inflammatory and immune processes thought to play a role in the development of the disease. These fatty acids enhance production of compounds called resolvins and neuroprotectins, which dampen and resolve inflammation. Both fatty acids may also help maintain or improve blood flow in the eye’s choroid – a highly vascular tissue layer located under the retina.

AMD Prevention is Key

An estimated 9 million US adults 40 years and older show signs of AMD, and treatment options are limited.

Most cases of severe vision loss are associated with advanced AMD – either the dry or wet form – which affects an estimated 1.7 million people. For those with moderate risk of developing advanced AMD, the antioxidant combination tested in AREDS has been shown to slow progression of the disease. There are also some treatment options for those with late-stage wet AMD.

But, for the additional 7.3 million who have early AMD there is no recognized means of prevention. That’s why it’s important to determine whether adopting a healthful lifestyle, including getting enough omega-3 and lutein, could make a difference in helping prevent this disease.

References

Christen WG, et al. Dietary omega-3 fatty acid and fish intake and incident Age-Related Macular Degeneration in women. Archives of Ophthalmology. March 14, 2011. [Epub ahead of print]