Dietary Changes, Supplements May Improve Ocular Health
BY WILLIAM L. MILLER, OD, PHD, FAAO
This column typically addresses treatment options, but for this issue, it will delve into the role of prevention. It's estimated that nearly $3 trillion are spent on treating diseases, many of which are preventable through a variety of means including some under our control. Diseases ranging from heart disease to diabetes can be modified, and in some cases prevented, by changing behaviors and nutritional habits. Estimates suggest that preventable deaths constitute up to 40 percent of the mortality in the United States every year.
Much of what influences our health and well-being is related to what we put or don't put into our bodies. A discussion of dietary habits might involve pointing patients to mypyramid.gov to reinforce their responsibility for healthy eating habits.
Our genetic make-up is also a powerful determinant but the interplay between what we are in control of and that which is already determined has only recently been discussed. Emphasis is now placed on patients becoming proactive by seeking ways to enhance their health rather than waiting to intervene after a disease process has begun. Of increasing interest is the area of chemoprevention, or the use of small chemicals in the form of vitamins, minerals and herbs to promote health. In this milieu are nutritional supplements, which are generally defined as food or parts of food that provide medical or health benefits and may prevent disease. In ocular disease, this includes dry eye dysfunction and age-related macular degeneration — and to a lesser extent, glaucoma and cataracts.
Most health professionals learn about medications from the case history but they discover very little about the nutritional habits of patients. Proper nutrition is a good starting point, but in reality, most of our patients don't eat properly and as they get older, the absorption rates for many essential vitamins and minerals decline. Elmadfa and Meyer (2008) showed that although two-thirds of patients used vitamins, less than half discussed vitamins with a healthcare professional. Vitamins and supplements are an essential part of the case history from a holistic point of view, but also because of possible interactions with medications.
Omega-3 fatty acid has been suggested to improve the ocular surface in patients who have tear film dysfunction by stabilizing the tear film. Anti-inflammatory effects can offer a supplemental adjunct to other dry eye therapies. They also play a role in the prevention of dry eye symptoms. The American diet has an approximate ratio of about 40:1 of omega-6 to omega-3, but most experts suggest an ideal ratio of 3 or 4:1. Suggest that patients increase their intake of fatty fish and increase their consumption of certain nuts, such as flaxseed and walnuts. If your patient isn't amenable to these foods, suggest an OTC fish oil capsule.
Another area of possible prevention is age-related macular degeneration (AMD). At present, supplementation appears to be helpful to those who have a certain level of existing AMD, but its potential for preventing or delaying the disease is still being investigated. The importance of lutein and zeaxanthin are being investigated in AREDS II, with results expected within the next 5 years. Other studies indicated the importance of carotenoids as anti-oxidant residents of the retina.
These interventions are cited for active ocular disease, but evidence suggests they may be beneficial for better overall health. For more information, visit optometricnutritionsociety.org, nutrition.gov or eatright.org. CLS
For references, please visit www.clspectrum.com/references.asp and click on document SE2010.
Dr. Miller is an associate professor and chair of the Clinical Sciences Department at the University of Houston College of Optometry. He is a member of the American Optometrie Association and serves on its Journal Review Board. You can reach him at email@example.com.