NIH Workshop Reviews Science Behind CardiovascularSupplements

NIH Workshop Reviews Science Behind CardiovascularSupplements

BETHESDA, Md.--The National Institutes of Health (NIH)concluded a meeting today that was held to allow an international group ofalternative medicine researchers and practitioners to exchange ideas, report oncurrent research and discuss ways to foster collaborative research on thecardiovascular effects of garlic, Ginkgo biloba, hawthorn and phytoestrogens.The workshop, titled Mechanistic Studies of Cardiovascular Effects ofBotanicals, was held here Aug. 22 to 23, and was jointly sponsored by theNational Heart, Lung and Blood Institute (NHLBI), the NIH Office of DietarySupplements (ODS) and the National Center for Complementary and AlternativeMedicine (NCCAM).

The goal of the workshop was to assess the current state of research on themechanisms of action responsible for the cardiovascular effects of severaldietary supplements, as well as to review evidence for those supplements'clinical efficacy. Attendees were expected to develop recommendations for futureresearch at the conclusion of the meeting.

"A lot of the recommendations had already been pre-generated by the twomeeting co-chairs," said John Cardellina, vice president of botanicalscience and regulatory affairs at the Council for Responsible Nutrition (CRN),who attended the meeting. "They were pretty typical kinds of things youwould see--let's make sure the materials that are going into clinical studiesare standardized, that their content and purity have been verified and there'san adequate supply of the same live materials to carry out through the wholestudy. ... There was also discussion of study design in terms of making sure thejournals that publish studies require that the study authors carefully andcompletely describe what they actually tested." Cardellina said somestudies generically name an herb without citing which species of plant, whetherit was aerial or root, how it was made or what dosage was used. "The pointof this recommendation is you have to be able to put this study in the contextof whatever else is already known about it," Cardellina added.

The workshop was divided into three sessions. The first and second sessionscovered garlic and ginkgo, and the third session covered flavonoid-containingbotanicals, such as hawthorn and phytoestrogens. Some highlights from themeeting included: "Introduction and Overview of the Chemistry and MedicinalProperties of Garlic," presented by Eric Block, Ph.D., of State Universityof New York at Albany; "Clinical Trials: Effect of Garlic Preparations onCardiovascular Disease and Its Risk Factors," presented by ChristopherGardner, Ph.D., of Stanford University; "Vascular Effects of Ginkgo Biloba:Pre-clinical Studies," presented by John Farquhar, M.D., of StanfordUniversity; "Hawthorn Extract for Congestive Heart Failure: Pre-clinicaland Clinical Studies," presented by Keith Aaronson, M.D., of the Universityof Michigan; and "Clinical Studies of the Cardiovascular Effects ofPhytoestrogens," presented by Gregory Burke, M.D., M.Sc., of Wake ForestUniversity.

"Overall, I'm happy with the outcome of the meeting because I think,largely, the studies that were discussed and the enthusiasm and interest levelof the researchers who were speaking were all solid," Cardellina said."I'm heartened to see that there is a very significant and large trial ofginkgo being done, there are two very substantial and what look to be meaningfultrials of hawthorn being done--one in the United States and one in Europe. It'sjust good to see we're picking up more momentum in conducting clinical trials onsome of these botanicals."

More on the workshop agenda can be found online (nccam.nih.gov/news/agenda/index.htm).