Supplements with lutein and zeaxanthin may help prevent macular degeneration, but levels of these ingredients vary widely across marketed supplements, according to a report from ConsumerLab.com, White Plains, NY. Among supplements specifically marketed for “eye health,” daily doses ranged from 2 mg to 20 mg for lutein and from zero to 16 mg for zeaxanthin. ConsumerLab.com also evaluated supplements containing astaxanthin, another type of carotenoid, which provides the pink color in salmon and may have therapeutic applications. All products passed laboratory testing confirming the listed amounts of lutein, zeaxanthin and/or astaxanthin, lack of lead contamination and proper disintegration of tablets.

In another test by ConsumerLab.com, supplements containing CLA (conjugated linoleic acid) showed that all but one of the selected products contained the listed amounts of this ingredient. CLA in supplements is typically derived from safflower seed oil, which also contains other fatty acids. A brand found to contain only 82% of its claimed CLA apparently listed the total amount of its safflower oil as being CLA.