|IJE – Cod Liver Oil and Cataracts
Leske MC, Wu SY, Connell AM, et al. Lens opacities, demographic factors and nutritional supplements in the Barbados Eye Study. Int J Epidemiol. 1997 Dec;26(6):1314-22.
This study evaluated the association of age-related lens opacities with the use of nutritional supplements and demographic factors among 4314 black participants (> or = 40 years) in the population-based Barbados Eye Study.
Lenses were classified at the slit lamp by the Lens Opacities Classification System II (LOCS II); a score > or = 2 was used to define the presence of gradable lens opacities, by type. Lens changes also included prior cataract surgery or cataract too advanced to grade. Associations with risk factors were evaluated by logistic regression analyses.
The study identified 1800 individuals with lens changes in at least one eye; 229 had nuclear opacities only; 851 had cortical opacities only. Older age and indicators of lower socioeconomic status (low education and/or non-professional occupation), were positively associated with both nuclear (odds ratio [OR] = 1.90) and cortical (OR = 1.47) opacities. Women had an increased risk of cortical opacities (OR = 1.41). Regular users of nutritional supplements were less likely to have lens changes (OR = 0.78) and, specifically, cortical opacities (OR = 0.77). The association with nutritional supplements was present in those < 70 years, but not at older ages.
The study supports the association of lower socioeconomic status with lens changes, including nuclear and cortical lens opacities. The findings also suggest that regular users of nutritional supplements have a one-fourth lower risk of lens changes and particularly, of cortical opacities; a result seen at ages under 70 years. The associations with potentially modifiable factors indicate the need for further evaluations, given the high prevalence of lens opacities.
The associations between age-related lens opacities and nutritional supplementation and selected demographic factors were investigated in 4314 men and women 41-84 years of age enrolled in the Barbados Eye Study. The Lens Opacities Classification System II was used for grading. 1800 of these adults had lens changes (defined as any type of gradable lens opacities, a history of cataract surgery, or cataract too advanced to grade) in at least one eye; 229 had nuclear opacities only and 851 had cortical opacities only. In logistic regression analyses, older age and low socioeconomic status (assessed on the basis of educational and occupational status) were positively associated with both nuclear (odds ratio (OR), 1.90) and cortical (OR, 1.47) opacities. The average age of participants with lens changes was 68.2 years compared with 51.8 years among those without such opacities. Compared with men, women had an increased risk of cortical opacities (OR, 1.41). Regular use of nutritional supplements (primarily cod liver oil and multivitamins) was associated with a decreased risk of lens changes (OR, 0.78), especially cortical opacities (OR, 0.77). The association with nutritional supplements did not persist beyond 70 years of age, however. The potential of nutritional supplements to reduce cataract in adults under 70 years of age could have significant public health implications, but requires confirmation in controlled clinical trials.
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