Nature’s Code ResveratrexConsumerLab.com has reported that tests of supplements containing resveratrol — a compound promoted as “life-extending” — revealed that two products provided only 43.4% and 86.7%, respectively, of their listed amounts of resveratrol. These two products were among the most expensive supplements of the ten products selected for testing by ConsumerLab.com.
Surprisingly, ALL of the lower-priced products fared well in the tests.
Results for all ten products are now published in ConsumerLab.com’s Review of Resveratrol Supplements. An additional nine products that passed the same testing through ConsumerLab.com’s Voluntary Certification Program are included in the report as well as one product similar to one that passed testing but sold under a different brand name.
Resveratrol products have proliferated following reports in 2006 of life-extending and athletic endurance-enhancing effects of resveratrol in animals. Sales of resveratrol supplements were estimated at $31 million in the U.S. in 2009 by Nutrition Business Journal.
Laboratory research has also shown antioxidant, anti-inflammatory, anticancer, and other effects. Human studies of resveratrol’s effectiveness have NOT been reported, but many are underway.
At least one researcher in the field, Dr. David Sinclair at Harvard Medical School, is noted as taking resveratrol personally at a dose of approximately 350 mg per day.
In addition to quality issues, ConsumerLab.com found the daily suggested dosage among resveratrol products to range from 50 to 1,020 mg of resveratrol. The cost to obtain 100 mg of resveratrol from products ranged from $0.15 to as much as $2.76 — more than a 17-fold difference.
Based on a daily dose of 400 mg of resveratrol, the daily cost would range from $0.60 to $11.04.
None of the products were contaminated with lead or cadmium, which can occur in plant-based supplements, and all tablets were able to properly break apart in solution.
“There is still much to learn about resveratrol,” said ConsumerLab.com’s president, Tod Cooperman, M.D. “At least those who choose to use it can now find out which products contain what they claim, which do not, and how to save money buying resveratrol.”
Brands covered in the new report are:
The two products that failed testing were:
The report also provides information regarding dosage and possible side-effects, and comparisons of active and inactive ingredients in the resveratrol products.
ConsumerLab.com is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. Their reviews of popular types of vitamins, supplements, and generic drugs are available here. Subscription to ConsumerLab.com is available online.
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