According to as Associated Press article, which ran on January 23rd, an American Heart Association (AHA), Dallas, TX, committee has revealed study results that are now casting doubt on the health claim that soy-based foods and supplements significantly lower cholesterol. The article claims that the findings could lead FDA to re-evaluate rules that currently allow companies to tout a cholesterol-lowering benefit on the labels of soy-based foods. The panel also found that neither soy nor its isoflavones reduced symptoms of menopause, such as “hot flashes.” Additionally, it claimed that isoflavones don’t help prevent breast, uterine or prostate cancer. Results, however, were mixed on whether soy prevented postmenopausal bone loss. Based on its findings, the committee said it would not recommend using isoflavone supplements in food or pills. Nutrition experts say soy-based foods still are good because they often are eaten in place of less healthy fare like burgers and hot dogs. But they don’t have as much direct benefit as had been hoped on cholesterol.

In response to this report, the Soy Nutrition Institute, Seattle, WA, said AHA “failed to note that soy protein could reduce coronary heart disease (CHD) at a level that would positively affect the nation’s health.” According to Dr. Mark Messina, adjunct associate professor and internationally recognized expert on the health effects of soyfoods, sufficient amounts of soy protein could potentially reduce CHD at the population level by as much as 10%. “Soy protein alone is certainly not going to bring cholesterol levels down to the target goal in hypercholesterolemics (people with high blood cholesterol), but soy’s modest cholesterol lowering effect by itself is beneficial. Plus, soyfoods are a good substitution for foods higher in saturated fat, which helps consumers follow an overall heart-healthy diet,” he said.

The AHA’s recent advisory statement on Soy Protein, Isoflavones and Cardiovascular Health has focused media attention on the modest effects of soy protein in lowering cholesterol levels in individuals. The AHA found an overall reduction in LDL cholesterol of three percent, which would translate into a six percent reduction of CHD risk (based on a one percent cholesterol reduction equaling a two percent CHD risk). However, Messina cites a recent meta-analysis of 33 studies involving more than 1,749 subjects, published in the American Journal of Clinical Nutrition, which showed that the addition of soy protein to the diet resulted in a 5.3 percent reduction in LDL cholesterol, which translates into a 10 percent CHD risk reduction. The impact on a public health basis could be significant and reduce CHD morbidity and mortality rates. Intriguing evidence also suggests that soy may exert other coronary benefits such as decreasing triglycerides and improving blood vessel elasticity.

Toward the end of December, an article appearing in Reuters Health claimed milk thistle does not appear to be effective for liver disease. This article was based on a study published in the November issue of The American Journal of Gastroenterology, which said that milk thistle was not only ineffective for liver disease but that its safety was also questionable. The lead researcher of the study, Dr. Christian Gluud of Copenhagen University Hospital in Denmark said, “We can’t see beneficial effects, we can’t exclude harmful effects and in order to know more we need to do more randomized trials to find out if they actually help.” According to the Reuters Health article, Dr. Gluud and his colleagues reviewed 13 clinical trials on milk thistle for liver disease due to alcoholism or hepatitis B or C. What they found was that milk thistle has no effect versus placebo on mortality rates of liver disease complications. “While the remedy appeared to reduce death from liver-related causes when all data was included, an analysis limited to best-quality studies found no effect,” researchers said. Dr. Gluud believes that herbal remedies should be held to the same standards as conventional medicine. “Sellers of such remedies must be required to have good evidence for any claims they make,” he said.