Keeping up with the onslaught of scientific information is a difficult but necessary part of educating consumers about the benefits and drawbacks of supplementation. Here?s a roundup of some of the newest research news. (Click here for more on research related to popular herbs and supplements.)
St. John?s wort and HIV
A study published online in the Oct. 27 issue of Gene Therapy found that protein extracted from St. John?s wort (Hypericum perforatum) suppresses HIV-1 expression and inhibits its replication. Kamel Khalili, Ph.D., and researchers at Temple University School of Medicine?s department of neuroscience and Center for Neurovirology made the discovery while studying the effect of St. John?s wort extracts on cell growth and the behavior of brain cells in vitro.
However, the researchers caution that the protein studied (named p27SJ) may not be present in the St. John?s wort available in supplement form. ?We don?t know yet how we have to deliver the protein to cells infected with HIV-1,? Khalili said. ?Even if the protein were present in the tablets, we don?t know how much might be present and whether the protein would be effective when ingested.?
Research published in June in The Journal of Nutrition described how magnesium deficiency in female rats affected their offspring. The team at the Division of Endocrinology and Metabolism of the National Institute of Nutrition in India found that maternal magnesium deficiency increased body fat and induced insulin resistance in offspring by the time they reached 6 months. Also, the addition of a perinatal magnesium-restricted diet impaired offspring?s glucose tolerance.
This follows a study published in Diabetes Care in May that found an association between magnesium deficiency and insulin resistance during childhood. According to the authors, based at the University of Virginia and the State University of New York at Buffalo, magnesium deficiency has already been associated with insulin resistance and increased risk for type 2 diabetes in adults. They concluded, ?Magnesium supplementation or increased intake of magnesium-rich foods may be an important tool in the prevention of type 2 diabetes in obese children.?
Mighty vitamin C
A growing body of evidence points to homocysteine?s link with coronary heart disease, but a recent study points to possible improvement with vitamin C supplementation. Researchers at the University of Occupational and Environmental Health in Kitayushu, Japan, found that acute hyperhomocysteinemia (elevated blood levels of the amino acid) restricted coronary blood flow and, further, that vitamin C supplementation recovered that flow. However, the researchers also found that in volunteers who received 2,000 milligrams of vitamin C at the same time as a homocysteine elevator, no velocity reduction occurred, thereby negating homocysteine?s negative effects. The study was published in the International Journal of Cardiology in September.
Vitamin E news
Researchers at Kyoto Prefectural University of Medicine have found that tocotrienols, which together with tocopherols compose the vitamin E family, are potent inhibitors of a key step in coronary plaque formation. In a complex cascade of events, circulating cells adhere to arterial walls due to expression of adhesion molecules. The study, published in the journal Atherosclerosis in May, found that tocotrienols prohibited those adhesion molecules from being expressed.
Alpha-tocopherol also prohibited this expression, but to a much lower degree.
In another study, researchers found that tocotrienols offered protection from free-radical induced bone loss in rats. Tocopherols also offered protection, but to a lesser degree. Researchers at the Department of Pharmacology at Universiti Kebangsaan Malaysia published the study in the journal Clinical and Experimental Pharmacology & Physiology in September. The authors wrote, ?Supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent all [free-radical]-induced changes.?
Understanding how CLA fights inflammation
Researchers at the University of Wisconsin-Madison reported in the Journal of Lipid Research in October that they have discovered the mechanism for conjugated linoleic acid?s reduction of inflammatory disease. The study, done in vitro and then in mice, found that a certain structural form of CLA blocked a key cellular pathway and thereby inhibited the COX-2 protein, which is known to play a significant role in inflammatory processes.
Natural Foods Merchandiser volume XXVI/number 12/p. 7