Color my macula

The macula is a bright yellow spot located near the center of the retina in the back of the eye. It helps protect the retina from harmful blue light and is responsible for sharp, central vision.

Two carotenoids-lutein and zeaxanthin-lend the macula its color. Since humans don't make these substances, macular health depends upon the diet to provide them.

Age-related macular degeneration is a condition characterized by destruction of the macula, which can eventually lead to central vision loss. Macular degeneration is more common in older people, women, smokers, people with high blood pressure, Caucasians, people with a family history of the disease, people with light-colored eyes, and obese people.

In addition to lutein and zeaxanthin, the omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are associated with a lower risk of macular degeneration.

A winning combo for eye health

The study investigated the effect of a dietary supplement containing lutein, zeaxanthin, DHA, and EPA on antioxidant capacity and macular pigment density in 172 people with age-related macular degeneration. Higher antioxidant capacity is associated with better free-radical protection and higher macular pigment density is associated with decreased macular degeneration risk.

The people were divided into three groups. For 12 months, Group 1 took 10 mg lutein, 1 mg zeaxanthin, 100 mg DHA, and 30 mg EPA per day; Group 2 took 20 mg lutein, 2 mg zeaxanthin, 200 mg DHA, and 60 mg EPA per day; and Group 3 took a placebo.

Antioxidant capacity, blood levels of lutein and zeaxanthin, and macular pigment density increased significantly in groups 1 and 2 after one month of taking the supplement and remained high throughout the study. At the end of the 12 months, people in Group 2 had significantly higher blood levels of DHA and EPA compared with Group 1 and the placebo group.

An ounce of prevention

Even if macular degeneration runs in your family, there's a lot you can do to decrease your risk:

• Don't smoke. People who smoke are about two times more likely to develop macular degeneration than are nonsmokers.
• Eat fish. Eating oily fish one or more times per week may slash the risk of macular degeneration by up to 50%.
• Start moving. Getting regular exercise can significantly lower the risk of macular degeneration.
• Eat a low glycemic index diet. People who eat more high-glycemic-index foods, like white bread, sugar, and potatoes, have a substantially higher risk of developing macular degeneration compared with people who eat lower glycemic index foods.
• Be colorful. Lutein and zeaxanthin are found in all sorts of leafy green veggies such as spinach, kale, and collard greens, as well as corn, zucchini, broccoli, Brussels sprouts, and egg yolks.

Lesa Werner, a naturopathic doctor with a background in ophthalmology says, "Some people might need an extra boost of lutein and zeaxanthin to help prevent macular degeneration." Werner suggests eating foods that are rich in these nutrients along with some fat and taking a digestive enzyme to increase their absorption.

(JAMA Ophthalmol 2013;doi:10.1001/jamaophthalmol.2013.2851)