Craig Blackwell, MD

Santa Cruz, CA
Diplomate: American Board of Ophthalmology
Fellow: American Academy of Ophthalmology

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An Ophthalmology Practice in Santa Cruz, CA

Diet, Exercise and Eye Health

August 25th, 2008

We all wonder what effect diet, exercise, sun exposure and other behaviors have on our general health and, since this is an eye site, our eyes. The proposition that we can take action to affect our health is an appealing idea to some and totally ignored by others. For those that are interested there are things you can do to affect your long term eye health.

One of the most significant articles to be published in 2007 was a review of literature regarding lifestyle exposures and eye disease, by Barbara and Ronald Klein. These authors, from the University of Wisconsin, have a decades long history as leading investigators in the epidemiology of eye disease making their comments particularly authoritative. (Amer J of Ophthalmol. 2007;144:961-969.)

Following are highlights from their review.

1. Cataract

Smoking. For every 10-pack-years of smoking the risk of cataract (nuclear type) increases 9%. (A pack-year amounts to smoking one pack per day for one year.) Smoking cessation reduces risk.

Diet and Supplements. Multiple large national studies have been done in the US, UK, Europe and Australia. Findings varied from study to study, and the recent AREDS group found no effect of their antioxidant formulation on cataract development. So if there is a protective effect it is mild. “Available data at this time are not sufficient to support a recommendation for taking high concentrations of vitamins, minerals, supplements, or a combination thereof to prevent cataract.” (p.963)

Light Exposure. It seems relatively clear that exposure to light, specifically Ultraviolet B, increases risk of cataract (cortical type). In the Beaver Dam, Wisconsin, group wearing glasses for refractive correction from an early age reduced nuclear cataract by 22% and cortical cataract by 33%. Wearing a hat and sunglasses reduced cataract slightly. Even so, a hat and UV protective lenses are recommended as prudent protective measures for people who spend a significant amount of time in the sun.

Note, UV protective coating is nearly clear. Dark glasses and polarization are helpful for comfort, but it is the UV coating that is protective.

2. Age-Related Macular Degeneration

Smoking. Increases risk of progression to late stage AMD; risk of 33% increase in atrophic form, and 25% increase in neovascular form. The risk is further increased in people with genes for Complement Factor H and LOC387715.

Diet and Supplements. AREDS is the one large randomized trial that found a positive effect of supplementing antioxidant vitamins and zinc. See Vitamins and Macular Degeneration for the details. Another 4 year, 1, 200 person study did not show any effect for Vitamin E alone.

The use of Lutein, Zeaxanthin and Omega-3 fatty acids have shown beneficial effects in epidemiologic studies. All three are being included in AREDS 2.

Light Exposure. Although there are theoretic reasons to expect macular damage from light, especially blue and UV, any effect on the retina must be small as it has not been detected in multiple large national studies.

Physical Activity. In one large study in Beaver Dam, Wisconsin, people who were significantly active at least 3 times a week were 70% less likely to develop neovascular complications. The authors point out this population had the same incidence of AMD and the same rate of geographic atrophy whether they exercised or not.

3. Diabetic Retinopathy

Smoking. Though multiple studies did not confirm the expected worsening of retinopathy with smoking, the authors recommend cessation of smoking because overall mortality is 1.5 times greater in diabetics who smoke.

Diet and Supplements. After controlling for blood sugar and blood pressure there are several studies showing that dietary supplements do not affect the course of diabetic retinopathy.

Physical Activity. Because exercise has such a good effect on diabetes in general it is unexpected that there is little epidemiologic data studying exercise and retinopathy.

4. Glaucoma.

There is no data suggesting smoking or dietary factors affect open angle glaucoma.

Small studies suggest exercise might help reduce pressure.

If you want to read the article in full it is in the American Journal of Ophthalmology, December 2007, pages 961 to 969. In the article each category has a discussion of the pertinent study or studies with a full set of references.

So, exercise is good for many things. Smoking is bad. UV protection is recommended. Dietary supplement with antioxidants probably helps slow macular degeneration.