ConsumerLab.com, White Plains, NY, purchased and tested more than 50 human and pet osteoarthritis supplements containing glucosamine, chondroitin and MSM and found some of the products to be contaminated with lead, missing certain listed ingredients or having inadequate labeling.
 
One-third of people who take multiple dietary supplements take a joint health supplement according to the latest ConsumerLab.com consumer survey. Sales of these supplements exceed $800 million, according to 2010 figures from Nutrition Business Journal (NBJ). Clinical studies suggest that the combination of glucosamine and chondroitin can reduce moderate to severe knee pain due to osteoarthritis. Chondroitin may also significantly decrease pain due to osteoarthritis of the hands. The evidence for MSM in treating osteoarthritis in people remains preliminary.
 
Among the 21 human products selected by ConsumerLab.com that contained glucosamine and/or chondroitin, four products failed to pass the review. A supplement sold by a national chain was contaminated with 13.2 micrograms of lead per daily serving—far exceeding the 0.5 mcg limit set by the State of California (the only state to set a limit), above which a warning label is required.
 
Three products for people were mislabeled: the most expensive supplement tested (costing over $2 per day) contained only 71.5% of its claimed chondroitin; another product lacked a required shellfish allergen warning (its glucosamine is made from crab shell), and another lacked a warning for people with the genetic disease phenylketonuria, as it contained the artificial sweetener acesulfame K.
 
In a separate review of products formulated for dogs, cats and horses, three of the six products selected by ConsumerLab.com passed quality criteria. One product contained only 4.5% of its chondroitin. Two products for dogs and/or cats contained lead above ConsumerLab.com’s limit (the same used for products for people). Lead was also found in one horse supplement. ConsumerLab.com also looked at pet foods promoted for “mobility” or “healthy joints” but careful review of their labels found they provided relatively little glucosamine and chondroitin.
 
In other developments, ConsumerLab.com recently reviewed vitamin E products. In an effort to determine what comprises a “natural” vitamin E supplement, cream or oil, the testing company said it depends completely upon the brand selling it. For some it is the full spectrum of naturally occurring tocopherols and tocotrienols in the vitamin E family. For others, it is primarily d-alpha-tocopherol (the most active vitamin E compound) with little of the related compounds. One product claiming to be “natural” was actually synthetic vitamin E.
 
In its recent product review, ConsumerLab.com selected and tested 13 different brands of vitamin E products. Eleven of these passed testing, meeting their label claims for natural or synthetic vitamin E. Among these, the least expensive were those with synthetic vitamin E, which cost as little as two cents per 400 IU (International Units) of vitamin E. Natural vitamin E supplements cost a bit more, starting at around eight or nine cents per 400 IU. However, if you are expecting tens or hundreds of milligrams of other vitamin E antioxidant compounds such as gamma-tocopherol, products cost more—starting at about 20 to 30 cents per 400 IU. Products with additional ingredients or topical creams or oils also cost more to get the same amount of vitamin E.
 
Vitamin E supplements are fairly popular in the U.S. In a 2011 survey of supplement users, ConsumerLab.com found that 22% of respondents were taking vitamin E supplements. Many people do not get sufficient vitamin E from what they eat, particularly those on low-fat diets or with medical conditions that cause malabsorption of fats, such as Crohn’s disease and cystic fibrosis. However, the group said some of the allure of vitamin E supplements was lost when studies showed that they did not protect against heart disease and might raise the risk of hemorrhagic stroke. Studies also showed that synthetic vitamin E might increase the risk of prostate cancer, although natural vitamin E may lower the risk. Sales of vitamin E supplements in the U.S. have fallen in recent years but have stabilized at around $340 million, according to NBJ. Preliminary research, largely in animals, suggests that natural vitamin E rich in gamma-tocopherol and, depending on the oil source, delta-tocopherol, may be more cancer preventive than alpha-tocopherol alone, which is the only form in synthetic vitamin E.
 
Lastly, ConsumerLab.com recently tested and reviewed many popular brands of magnesium supplements. Among the noteworthy findings was one product that was found to contain only 45% of its listed magnesium despite boasting a “GMP” (Good Manufacturing Practices) seal on its label. Another violated a FDA labeling rule by displaying a heart symbol although there is no approved heart health claim for magnesium. Several other supplements contained their listed amounts of magnesium, were free of lead contamination, and if tablets, were able to properly break apart.
 
The testing company also found the cost to obtain an equal amount of magnesium from supplements ranged from as little as $.02 to more than $1.30. However, spending a little more than the lowest price may be worthwhile to get a form of magnesium that is better absorbed and less likely to cause diarrhea.
 
Forms covered in the review included: magnesium aspartate and orotate, magnesium citrate, magnesium chloride, magnesium lactate and lactate dehydrate, and magnesium oxide. ConsumerLab.com evaluated magnesium supplements sold as tablets (including caplets and enteric and time-release pills), capsules (including softgels), powders, liquids, as well as calcium-magnesium supplements.
 
Magnesium supplements are commonly used to help treat and prevent magnesium deficiency, which elevates blood pressure and increases the risk of osteoporosis. Deficiency can result from many causes including the extended use of proton-pump inhibitors, such as Nexium and Prilosec. Magnesium supplements can also help prevent migraine headaches, menstrual pain and improve insulin sensitivity. Sales of magnesium supplements reached $430 million in 2011, up 14% from the prior year and up 79% from 2006, according to NBJ.