Systematic review of the effects of ginseng on cardiovascular risk factors.

OBJECTIVE To examine the evidence for the efficacy of ginseng (Panax spp.) on cardiovascular risk factors, including blood pressure, lipid profiles, and blood glucose, and to summarize reported cardiovascular adverse events. DATA SOURCES We searched MEDLINE, AMED, BIOSIS, CAB, EMBASE, and the Cochrane Controlled Trials databases through July 2005 and performed hand searches of bibliographies. STUDY SELECTION AND DATA EXTRACTION Short- or long-term, randomized, controlled trials and nonrandomized studies published in English were included. Data were extracted in a standardized manner, and 2 independent investigators assessed methodologic quality of the studies. Thirty-four studies were identified with results for blood pressure, lipids, and/or blood glucose. Due to heterogeneity of the studies, we were unable to perform a meta-analysis. Data on cardiovascular adverse events were extracted from events reported in identified studies and from case reports. DATA SYNTHESIS The majority of studies were short term. Ginseng may slightly decrease blood pressure compared with placebo (range 0-4%). We found mixed results for an effect on lipids, with 5 of 9 studies showing improvement in one or more lipid parameters compared with baseline (range 7-44%). We identified several studies showing that ginseng lowers blood glucose, but overall studies were inconsistent. CONCLUSIONS Current evidence does not support the use of ginseng to treat cardiovascular risk factors. Some studies suggest a small reduction in blood pressure. Despite some evidence showing that ginseng lowers blood glucose and improves lipid profiles, well-designed, randomized, controlled trials evaluating its effects are lacking.