Diet (2008, 2016) Glaucoma Risk Reduction through Nutrition
Researchers evaluated dietary data from the Nurses' Health Study which comprised almost 64,000 women over 28 years, as well as data from the Health Professionals Follow-up Study which comprised over 41,000 men over a 26 year period. Because the presence of oxygen, supplied to the eye as nitric oxide, has been reported to be a positive factor in the development of primary open angle glaucoma. Nitrates in green leafy vegetables contribute significantly to oxygen in the blood and so the diets of these more than 100,000 subjects was evaluated with respect to the incidence of glaucoma. The subjects were followed every two years over the 26 or 28 year period.
The researchers found that the subjects with the highest 1/5th levels of green leafy vegetables in their diets had up to 30% less risk of glaucoma incidence compared to the subjects with the lowest 1/5th amounts of the nitrate-rich green leafy vegetables. The lowered risk rate was especially significant for early paracentral glaucoma with early vision field loss where the risk was 40 to 50% less.
Researchers: J. H. Kang, W. C. Willett, et al.
Published: Association of Dietary Nitrate Intake With Primary Open-Angle Glaucoma: A Prospective Analysis From the Nurses' Health Study and Health Professionals Follow-up Study, JAMA Opthamology, January 2016.
Several studies published in 2008 looked at glaucoma risk and nutrition and found a possible relationship between eating fruits and vegetables and lowered glaucoma risk.
The first study investigated whether specific nutrients might account for an apparent relationship between glaucoma risk and fruit and vegetable consumption. The researchers also investigated potential links between glaucoma risk and antioxidants, calories, fat, protein, and carbohydrates obtained from natural food sources. The study evaluated data from the Study of Osteoporotic Fractures Research Group1.
- Glaucoma risk was decreased 69% in women who consumed at least one serving per month of green collards and kale compared with those who consumed fewer than one serving per month.
- Glaucoma risk was decreased 64% in women who consumed more than two servings per week of carrots compared with those who consumed fewer than one serving per week.
- Glaucoma risk was decreased 47% in women who consumed at least one serving per week of canned or dried peaches compared with those who consumed fewer than one serving per month.
Researcher: Anne L. Coleman, MD, PhD, professor of ophthalmology in the Jules Stein Eye Institute of the David Geffen School of Medicine at the University of California Los Angeles and professor of epidemiology in the UCLA School of Public Health, study published in the American Journal of Ophthalmology, 2008
The second study drew data from the same research1.
This study further analyzed the results of the first study above regarding the effects of nutrition on the African-American community who have a higher percentage of glaucoma.
The data included 584 black women of whom 13% had glaucoma in at least one eye.
- Three or more servings per day of all fruits or fruit juices decreased the odds of glaucoma by 79% compared to consuming less than one serving per day.
- Eating more than two servings per week of fresh oranges and peaches was associated with less glaucoma risk.
- Eating more than one serving per week of green collards or kale decreased the odds of glaucoma by 57% compared to 1 serving per month or less.
- There was a protective trend for glaucoma in those eating more fruit or fruit juices), fresh oranges, fresh peaches, spinach), and green collards or kale.
- Higher intakes of some nutrients were also associated with decreased risk: vitamin A; folate; a-carotene; beta-carotene; and lutein/zeaxanthin.
The researcher notes that it's dangerous to draw too many conclusions from the nutrition-related data found so far, saying that the studies are exploratory and there are clear associations, but not conclusive proof, that, for example, eating collards prevented glaucoma. There could be environmental differences or differences in how their bodies metabolize nutrients. But the association was worth pursuing.
Researcher: JoAnn A. Giaconi, MD, assistant clinical professor of ophthalmology at the Jules Stein Eye Institute at UCLA. Published: Giaconi JA, et al. IOVS 2008;49; ARVO E-abstract 5453.
- Coleman AL, Stone KL, Kodjebacheva G, Yu F, Pedula KL, Ensrud KE, Cauley JA, Hochberg MC, Topouzis F, Badala F, Mangione C; Study of Osteoporotic Fractures Research Group