Trend found for link between polyunsaturated fat intake, glaucoma risk

A high ratio of polyunsaturated fat intake appears to increase the risk of developing primary open-angle glaucoma, specifically high-tension glaucoma, according to a large study.

Jae H. Kang and colleagues at Harvard School of Public Health and other institutions prospectively studied the dietary fat intake of thousands of participants in two large studies to determine whether correlations existed between fat consumption and POAG. The study populations, the Nurses’ Health Study and the Health Professionals Follow-Up Study, included 76,199 women and 40,306 men, respectively, all free of glaucoma at baseline.

The women were followed from 1980 to 1996 and the men from 1986 to 1996 if they were older than 40 and reported undergoing eye examinations during follow-up. Food-frequency questionnaires were used to assess energy-adjusted cumulative averaged fat intakes. The researchers identified 474 self-reported POAG cases that were confirmed by medical chart review.

Neither major fats nor fat subtypes were independently associated with risk of POAG. Pooled rate ratios for POAG comparing the highest quintile to the lowest were 0.9 for total fat, 1.03 for saturated fat, 0.76 for monounsaturated fat and 0.87 for polyunsaturated fat. None of these was statistically significant.

The researchers found “a suggested positive association” between a higher ratio of n-3 to n-6 polyunsaturated fat and POAG risk. The risk was stronger for high-tension POAG, the researchers said. They recommended further studies to confirm their findings.

The study is published in the May issue of The American Journal of Clinical Nutrition.