Lutein / zeaxanthin and Omega-3 poly-unsaturated fatty acids in AMD

The supplements used in the Age-Related Eye Disease Study (AREDS) were vitamin C, vitamin E, beta-carotene, and zinc (see the July 5th blog). There is accumulating data however that lutein / zeaxanthin and omega-3 poly-unsaturated fatty acids may also help reduce the progression of AMD. Lutein and zeaxanthin are members of the carotenoid family, like beta-carotene, and are the only two carotenoids in the macula. They are much more concentrated in the macula than anywhere else in the body so you would think that they must be there for a reason. Lutein and zeaxanthin protect against light damage by being very efficient absorbers of blue light, which has the most energy in the visible spectrum and is the most damaging. You could think of them as sun block for the macula. They are also good anti-oxidants and scavenge reactive oxygen molecules like the antioxidant vitamins.

The Age-Related Eye Disease Study ranked their study participants into five groups according to the amount of dietary intake of lutein and zeazanthin. The group who had the highest intake, the top twenty percent, had a forty percent reduction in the risk of atrophic or neovascular AMD. These patients probably were the ones who had an overall healthier diet and ate all those good things like carrots and squash and spinach so it is unknown whether it was the overall diet or just the lutein and zeaxanthin which made the difference. Smokers have less lutein and zeaxanthin pigment in their macula and some researches believe that may be one mechanism why smokers have an increased risk of AMD.

The National Eye Institute is planning a study called AREDS 2 which will test whether supplementation with lutein and zeaxanthin slows the progression of AMD. The planned doses have been tentatively set at ten milligrams of lutein and two milligrams of zeaxanthin daily. Patients with AMD may decide that they should go ahead and take these supplements now thinking that at least they won’t be harmful. We don’t know that for sure, however. We thought that beta-carotene supplementation would be helpful in smokers and then discovered that it increased the risk of lung cancer. We thought that very high doses of vitamin E might protect against heart attacks and found that the opposite may be true.

The other emerging story in that of omega 3 poly-unsaturated fatty acids. These fatty acids are mainly found in fish and nuts. These fatty acids have anti-inflammatory properties and may be anti-angiogenic, which may mean that they protect against the formation of the new blood vessels found in the wet form of AMD. A number of studies have found a reduced risk of AMD in patients who have diets rich in omega-3 poly-unsaturated fatty acids. For instance in the AREDS study there was a fifty percent reduction in advanced AMD for the group who had the highest intakes compared to the group who had the lowest. It didn’t take much of the omega 3 poly-unsaturated fatty acids to be effective because the highest intake group on average ate only one serving of broiled or baked fish a week. The National Eye Institute’s AREDS 2 trial will also test if supplementation with omega 3 poly-unsaturated fats reduces the progression of AMD.

If you have AMD, you could run out and buy supplements that contain lutein / zeaxanthin or omega-3 poly-unsaturated fats. Or probably better yet you could eat one serving of a vegetable every day that contains a lot of lutein / zeaxanthin such as kale (22 mg per cup), spinach (15mg per cup), broccoli, peas, or brussels sprouts two servings per week (for omega-3) of salmon, sardines, herring, trout, halibut, soybean oil, or walnut oil. That diet will give you plenty of both lutein / zeaxanthin and omega-3 oils.