ARS | Publication request: Dietary Linolenic Acid Intake Is Positively Associated with Five-Year Change in Eye Lens Nuclear Density

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 1, 2007
Publication Date: April 1, 2007
Publisher's URL: http://www.jacn.org/cgi/content/abstract/26/2/133
Citation: Lu, M., Taylor, A., Chylack, L.T., Rogers, G., Hankinson, S., Willett, W., Jacques, P. 2007. Dietary linolenic acid intake is positively associated with five-year change in eye lens nuclear density. Journal of Nutrition. 26(2):133-140.

Interpretive Summary: Cataract is the leading cause of blindness in the world today. In the United States, the majority of elderly will suffer some visual impairment as a result of cataract. Clearly, finding ways to delay cataract formation would enhance the quality of life for older individuals and substantially reduce the personal and societal economic burden associated with treating cataract. Animal experiments have shown that dietary fat intake can change lens fiber cell membrane composition and function and affect risk of cataract formation, while the development of cataract in humans changes the fatty acid composition of the lens fiber cell membranes. In spite of the potential importance of dietary fat in maintaining the integrity of the aging lens, there has been little human research on dietary fat intake and risk of cataract. We recently reported that the prevalence of newly diagnosed, age-related nuclear cataract was positively associated with linolenic and linoleic acid intake. In the present study conducted in this same group of women, we examine relationship between dietary fat intake and the change in the degree of opacification of the core or nucleus of the eye lens over a five-year follow-up period. The degree of opacification of the eye lens nucleus was 16% greater after five years in the women with the highest linolenic acid intake compareD with those who had the lowest intakes of this fatty acid. There were no significant associations between other dietary fats and change in nuclear opacification. Our data suggest a role for dietary fat, in particular linolenic acid, in the development of cataracts in the core or nucleus of the eye lens.

Technical Abstract: Dietary fat may affect lens cell membrane composition and function, which are related to age-related cataract. The study was designed to examine the associations between dietary fat and the change in nuclear lens opacification over five years. Women aged 53 to 73 years without previously diagnosed cancer, diabetes and cataracts from the Boston, Massachusetts area were selected from the Nurses' Health Study cohort. Four hundred forty women participated in a baseline (1993-95) and a follow-up (1998-2000) eye examination. Intakes of total fat and selected fatty acids were calculated as the average intake from five food frequency questionnaires that were collected between 1980 and baseline. Change in amount of nuclear density (opacification) was characterized by the difference between baseline and follow-up in pixel density at the central clear zone in the Scheimpflug slit image of the lens. Intake of linolenic acid was positively associated with change in nuclear density. The geometric mean nuclear density change was 16% greater in the highest quartile category of linolenic acid intake than in the lowest quartile category (P for trend=0.05). For women in the high tertile baseline nuclear lens opacification group, the geometric mean change in the highest quartile category of linolenic acid intake was 70% higher than the change in the lowest quartile category (P for trend=0.01). There were no significant associations between other dietary fats and change in nuclear density. In conclusion, high intake of linolenic acid was associated with a greater age-related change in lens nuclear density.