CLINICAL

  nutrition

AREDS 2 Supplements

Can patients get these nutrients from food alone?

KIMBERLY K. REED, O.D., F.A.A.O.

A 57-year-old female patient with fair skin and green eyes presented for her annual eye exam. She had numerous small drusen OU, a family history of AMD and a past history of smoking. After I discussed with her the importance of a nutritional supplement in reducing the risk of AMD vision loss, she replied, “I eat spinach salad all the time, so I don’t need an extra supplement.” Is she right?

The answer

The technically correct answer is “yes,” but with three significant caveats: (1) Fewer than 10% of U.S. adults even approach the levels desired (10mg of lutein and 2mg of zeaxanthin); (2) nutrients from food and supplements aren’t exactly the same; and (3) available evidence is only truly accurate related to the specific foods or supplements tested. Harvest time, soil conditions and even prevailing weather can affect a food’s nutrient value.

A closer look

Lutein and zeaxanthin are classified as xanthophylls, which are a subgroup of carotenoids. Surprisingly, carotenoids are best absorbed when cooked instead of raw. The difference in absorption may be as much as 100%, says the Journal of Food Composition and Analysis. Specifically, the lutein content for 100g (about 3.5 ounces) of raw spinach is 6.6mg and 12.6mg cooked. So, an average consumption of 10mg of lutein daily would require just about one average-sized (six ounces) bag of spinach as a salad every day!

Also, consider this: When foods containing carotenoids are eaten with dietary fat, they are better absorbed than when eaten alone or with a low- or no-fat accompaniment. So, low-fat dressing on the above patient’s spinach salad, for example, might not be the best route for xanthophyll absorption.

Something else to contemplate: Nutrient bioavailability from food is boosted when vegetables containing carotenoids are chopped, pureed or blended. This is because the plant cell wall matrix must be broken down to release the carotenoids, which are then mixed with bile salts and lipids. This is not necessary with supplements, as the lutein and zeaxanthin are already in micelles.

It’s important to note, however, that little “tweaks” in other foods might make a difference. For example, orange peppers contain roughly 1.5 times the amount of lutein and nearly 10 times the amount of zeaxanthin as their red counterparts. Green peppers have less lutein than orange peppers and contain no zeaxanthin. (See “A Retinal Powerhouse Meal,” left.)

That female patient

I told the spinach salad-loving patient it would take about four cups of raw spinach daily to reach the minimum amount of just a few of the nutrients that may help her. She opted for an AREDS2-based supplement. OM

DR. REED IS AN ASSOCIATE PROFESSOR AT THE NOVA SOUTHEASTERN UNIVERSITY COLLEGE OF OPTOMETRY IN FORT LAUDERDALE, FLA., A MEMBER OF THE OCULAR NUTRITION SOCIETY AND AUTHOR OF NUMEROUS ARTICLES ON OCULAR NUTRITION, DISEASE AND PHARMACOLOGY. SHE IS ALSO A FREQUENT CONTINUING EDUCATION LECTURER. TO COMMENT ON THIS COLUMN, E-MAIL DR. REED AT KIMREED@NOVA.EDU, OR SEND COMMENTS TO OPTOMETRICMANAGEMENT@GMAIL.COM.