Thursday, August 10, 2006
Smoking, Fish and Omega-3 Intake Associations with AMD
Taken from Optometric Physician Volume 6 #29, 2006:
The U.S. Twin Study of Age-Related Macular Degeneration (AMD) is comprised of elderly male twins from the National Academy of Sciences-National Research Council World War II Veteran Twin Registry to determine genetic and environmental risk factors for AMD. Twins were surveyed for a prior diagnosis of AMD and underwent an eye examination, fundus photography and food frequency and risk factor questionnaires. The environmental component of the study includes 681 twins, 222 of which have AMD (intermediate or late stages) and 459 who have no maculopathy or early signs.
Current smokers had a 1.9-fold increased risk of AMD while past smokers had about a 1.7-fold increased risk. Increased intake of fish reduced risk of AMD, particularly for two or more servings per week. Dietary omega-3 fatty intake was inversely associated with AMD. Reduction in risk of AMD with higher intake of omega-3 fatty acids was seen primarily among subjects with low levels of linoleic acid intake, an omega-6 fatty acid. The attributable risk percentage was 32 percent for smoking and the preventive fraction was 22 percent for higher omega-3 intake.
This study of twins provides further evidence that cigarette smoking increases risk while fish consumption and omega-3 fatty acid intake reduce risk of AMD.
SOURCE: Seddon JM, George S, Rosner B. Cigarette smoking, fish consumption, omega-3 fatty acid intake, and associations with age-related macular degeneration: the US Twin Study of Age-Related Macular Degeneration. Arch Ophthalmol 2006;124(7):995-1001.