A Little Is Good – A Lot May Not Be Better

By Dr. Lisa Lex

Offering guidance to our patients when there is either a family history of age-related macular degeneration (AMD) or evidence that a patient has clinical signs of the disease is sometimes challenging.

I always begin with the non-controversial advice: wear UV protection (wrap-around style for true outdoor enthusiasts) and a brimmed hat when outside.  I remind them “that the sun does to your eyes what it does to your skin–prematurely ages them.”

If they smoke I discuss the effects their habit has on ocular health, tripling the risk of AMD. I encourage them that if they have tried to quit before that they should keep trying as evidence shows that the more attempts at quitting, the more likely they are to eventually succeed.

Recommending patients take a systemic supplement can have potential consequences, however. I prefer to keep things as simple and safe as possible.   Betacarotene in large amounts has the potential to increase lung cancer in those who are smokers.  It also interferes with the absorption of two other important carotenoids, lutein and zeaxanthin. Vitamin E in amounts higher than recommended (22.5 IU or 400-800 mixed tocopherols) are suspected to increase the risk of hemorrhagic strokes as well as prostate cancer. It also can interfere with the absorption of statins and increase the risk of heart failure in diabetics.  Zinc’s recommended daily requirement of 15 mg is far exceeded in vitamins targeted for eye health and can cause genitourinary and gastrointestinal disorders. So what’s an eye doc to do?

I inquire specifically of the patient, in addition to their medications, what supplements they are taking. The list can be alarmingly long and I remind them to share that list with their doctor. In an attempt to offer what I know to be safe, and potentially effective, I encourage my patients to eat good amounts of colorful fruits and vegetables. We know kale, spinach, eggs (yolks), corn, orange peppers and grapes are excellent sources of ingredients that help maintain macular health. It may also be helpful to take a 6-20 mg capsule of lutein in a formula with zeaxanthin, preferably 2 mg.  For those who are deficient, the AREDS2 study found both a slowing of the progression of AMD and a decrease in cataract in those supplementing these two carotenoids. A multivitamin may also be beneficial, but better if they find one that contains little to no betacarotene.

Most importantly, I write down my recommendations and advise the patient of the confusion that awaits them in the vitamin aisle. There are SO many choices and if directions and ingredients are not looked at carefully, there is a chance that a little good could do a lot of harm.

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