Some optometrists are very aware of the role of nutrition in systemic and eye health and give it a prominent role in discussions with patients; others may refer to it only peripherally while reviewing a patient history form. But trends indicate widespread interest in better health, and perhaps optometrists should be more assertive about nutrition counseling, Kimberly Reed, OD, FAAO, recently suggested.
More than one-half of all Americans use nutritional supplementation—mostly multivitamins—and spend about $27 billion a year on products.
"Our patients are spending that money. They may balk at upgrading their lenses in your office, but they're spending money on their vitamins. I think that's something to bear in mind. People are willing to spend their money to be healthier and to age more slowly," said Dr. Reed, associate professor, Nova Southeastern University College of Optometry, Fort Lauderdale, FL.
You may be reluctant to counsel your patients about nutrition because you feel you aren't well informed and don't want to offer misleading advice, she said. Good information sources for you and your patients include the American Optometric Association and the Ocular Nutrition Society.
Dr. Reed incorporates nutrition into her practice as soon as someone becomes a patient, not by recommending a supplement but by beginning the education process. At first, her only recommendation may be to eat healthier food.
"I have never had anybody be offended when I've talked with them about health and wellness," she said, adding that it's a more sensitive approach than focusing the discussion on weight.
As you delve into nutrition with your patients, you should be prepared to discuss some of the most widely used supplements and those most likely to be beneficial.
"Omega-3 fatty acids are by far the most critical element that we need to be recommending to our patients, our family, our kids, and our neighbors," Dr. Reed said.
Evidence suggests that omega-3 eicosapentaenoic acid (EPA) and docohexaenoic acid (DHA) have a number of health benefits. Omega-6s are also important, but many experts believe that Americans eat too many omega-6s and too few omega-3s. The ideal ratio, however, is still uncertain.
Dr. Reed recommends that healthy patients consume about 1,500 mg/d of DHA and EPA, the primary beneficial omega-3 fatty acids. If a patient is healthy systemically but has ocular disease, her recommendation is 2,500 mg/d, and up to 3,000 mg/d for severe dry eye patients.
Supplementation should be titrated based on factors such as the patient's weight, height, and diet. Always co-manage patients who are on any blood-thinning drugs, and consult a pregnant or breastfeeding patient's obstetrician before recommending supplementation.
Lutein and zeaxanthin are powerful antioxidants found together in many vegetables. Several large studies have shown that high amounts of these carotenoids may protect against age-related macular degeneration (AMD) and cataracts.
A reduction in the overall prevalence of AMD during a study period of 2005 to 2008 may reflect the benefit of increased consumption of eye vitamins containing these nutrients, Dr. Reed said.
She recommended consuming 10 to 20 mg/d of lutein and 2 to 5 mg/d of zeaxanthin. Individuals who eat a diet high in green, leafy vegetables and other colorful vegetables and fruits may get a sufficient amount without supplementation, but the content of lutein and zeaxanthin in foods is highly variable.
Coenzyme Q10 is a compound involved in energy production and an important antioxidant. It may be useful in treating cancer, although there have been no large clinical trials. As a nutritional supplement, the recommended amount is usually 30 to 90 mg/d in divided doses. It is a hypotensive agent and should also be used with caution in patients who have hypoglycemia.
Many people are deficient in vitamin D because they spend so much time inside. A simple recommendation you can offer patients is to get 10 to 30 minutes of sunlight per day, Dr. Reed said. Good dietary sources of vitamin D include certain kinds of fish, especially salmon, and fortified milk. The recommended dietary allowance for most healthy adults is 600 IU per day, but when deficiency is diagnosed, short-term supplementation at much higher doses is recommended. The upper safe limits of vitamin D supplementation are still being debated.
Vitamin C is available in fruits and vegetables, but supplementation may be necessary when dietary intake is low. It is unclear whether vitamin E supplementation is harmful, and Dr. Reed rarely recommends it.