AMD protection in fish consumption

Magic Time

You could say the retina is the “backstage” of the eye – the place where all the magic happens.

When the lens of the eye projects light onto the retina at the back of the eye, several layers of highly specialized cells and photoreceptors convert the light into neural signals that are transmitted to the brain.

But when the center of the retina – the macula – becomes corrupted, the brain receives incomplete signals and vision becomes impaired. This is what happens in age-related macular degeneration (AMD), the leading cause of blindness in people over the age of 50.

But here’s a little more magic: Something in fish oil helps keep the retina healthy.

Blue mountains

A new study from two Australian research centers that specialize in vision research confirms earlier trials that have found AMD protection in fish consumption.

STUDY ABSTRACT

• The Australian team recruited more than 2,300 subjects over the age of 49 (average age was 64) who had participated in the Blue Mountains Eye Study
• Retinal photographs measured AMD in each subject
• Dietary intake was assessed with food frequency questionnaires, and about 80 subjects completed three additional detailed food records
• After a five-year follow up, researchers found that subjects who ate at least one fish serving each week reduced early AMD risk by 40 percent
• Late AMD risk was reduced by 70 percent among subjects who ate three or more servings of fish each week

NutraIngredients reports that the Australian team will continue to study the same group to determine if long-chain omega-3 poly-unsaturated fatty acids in fish oil protect against AMD development over a 10-year follow up.

Additional defense

The results of the Australian study parallel the outcome of another study I told you about in the e-Alert “Rockets’ Red Glare” (7/1/03), in which omega-3 consumption through fish intake was analyzed in 4,500 subjects at risk of AMD. Researchers found that those who ate one serving of fish each week (four ounces of tuna, or broiled or baked fish) reduced their risk of developing “wet AMD” (the most damaging type of AMD) by about one-third. Two fish servings per week cut wet AMD risk in half.

But getting plenty of omega-3 fatty acids from fish is not the only way to protect yourself from AMD. Certain vitamins and minerals also add to AMD defense.

In 2001, Age-Related Eye Disease Study (AREDS) researchers divided 3,600 subjects over the age of 55 into four groups to receive one of these daily supplement regimens:

• Antioxidants (500 mg vitamin C, 400 IU vitamin E, 15 mg beta carotene)
• Zinc (80 mg zinc oxide, 2 mg cupric oxide)
• Combination of antioxidants and zinc in the same doses
• Placebo

Each subject was given an eye exam every six months. After more than six years researchers found that subjects in the antioxidant group had a 17 percent lower rate of AMD development compared to placebo. Those in the zinc group had a 21 percent lower rate, and those in the combined group cut their risk of AMD by 25 percent.

As I’ve noted in previous e-Alerts, people over the age of 60 – especially smokers and people with a family history of AMD – are at greatest risk of developing the disorder. Women tend to be at slightly greater risk than men. And ACE inhibitor drugs (used to address blood pressure) have also been shown to increase risk.

If you’re concerned about AMD, talk to your doctor before adding additional supplements to your daily regimen.

Sources:
“Dietary Fatty Acids and the 5-Year Incidence of Age-Related Maculopathy” Archives of Ophthalmology, Vol. 124, No. 7, July 2006, archopht.ama-assn.org
“More Support that Fish Oil Could Reduce AMD” NutraIngredients-USA, 7/11/06, nutraingredients-usa.com