Life is full of opportunities for conflict and health care is no exception to that paradigm. Nutrition in particular seems to be a frequent subject of conflicting expert opinions. In eye care we intersect with the nutrition world because some causes of sight loss are linked with nutritional risk factors. Diabetes and macular degeneration are two of the leading causes of vision loss in adults that have clear nutritional links. I’m only going to discuss one of the major areas of conflict related to treating macular degeneration (leading cause of severe, irreversible vision loss in people over age 60).
The conflict in eye care relates to two areas of studies that have some conflicting information. The AREDS (Age Related Eye Disease Study) and AREDS 2 studies are two of the biggest nutritional studies published over the last 20 years. These studies showed that taking a supplement containing antioxidants (Vitamin C and Vitamin E) carotenoids (Lutein, Zeaxanthin, and beta carotene) and Zinc slowed the progression of macular degeneration. The AREDS 2 study showed that formulations containing between 25-80 mg of zinc had similar effect. The most popular formulation called Preservision currently has 80 mgs per day as it’s dosage amount. Here is where the conflict begins. Two independent studies each with close to 1000 participants showed that about 14% of people with specific genetic make-ups may show faster progression of their macular degeneration when placed on high dosage of Zinc (80mg).
Let’s try to dig deeper. Eighty mg of zinc is 7-10 times greater than the recommended daily allowance. Furthermore, the food and nutrition board of the Institute of Medicine recommended that people limit their intake of zinc to 40 mg per day. High doses of zinc have been linked to prostate cancer and increase in genitourinary hospitalizations.
So now what?
We recommend that all patients who are taking high dosage zinc supplements has a simple genetic test. The test involves taking a cheek swab and sending it to a laboratory for results. It will see if you are genetically predisposed to issues from high zinc. Make it simpler and choose a supplement with 40mg or less zinc per day. We offer genetic testing for macular degeneration in our office. The test is generally covered by insurance and Medicare has recognized the value of this type of testing. Most people would also benefit from a supplement that contains antioxidants as well as lutein and zeaxanthin. Fish oil, (while again is controversial) we suggest most people to take a high quality triglyceride form fish oil daily. We see that positive evidence is in its favor. Here’s to your health! Bon Appetite.