Known commonly as Indian ginseng or winter cherry, Ashwagandha is a plant in the nightshade family. For thousands of years, it has been used as a restorative in Ayurvedic medicine. Its name in Sanskrit means “the smell of a horse.” The name implies that the herb imparts the vigor and strength of a stallion. Traditionally it was used to help strengthen the immune system—especially after a patient had been ill, but human studies show that it also decreases anxiety and stress.[i]
In one study highlighted by the National Institutes for Health, 64 subjects with a history of chronic stress who were given the high-concentration full-spectrum Ashwagandha root extract exhibited a significant reduction in scores on all the stress-assessment scales, relative to the placebo group. The serum cortisol levels were substantially reduced in the Ashwagandha group, relative to the placebo group. No serious adverse events were reported. Multiple animal studies have come to same conclusions: Ashwagandha supplementation consistently reduces cortisol levels and improves many stress-related symptoms.
In another human study, Ashwagandha increased serum T-cell count, and killer-cell count, suggesting that it can boost immune function. A recent study from the Journal of the International Society of Sports Nutrition shows the effectiveness of this adaptogenic herb in muscle strength and muscle recovery.[ii] Following baseline measurements, both groups of subjects underwent resistance training for 8 weeks and measurements were repeated at the end of week 8. The primary efficacy measure was muscle strength. The secondary efficacy measures were muscle size, body composition, serum testosterone levels and muscle recovery. Muscle strength was evaluated using the 1-RM load for the bench press and leg extension exercises. Muscle recovery was evaluated by using serum creatine kinase level as a marker of muscle injury from the effects of exercise. Compared to the placebo subjects, the subjects receiving Ashwagandha also had significantly greater reduction of exercise-induced muscle damage as indicated by the stabilization of serum creatine kinase.
A pair of studies was done on infertile subjects. After taking the herb for 90 days, subjects noted a significant increase in testosterone, and improved sperm quality. Ashwagandha stimulates testosterone production at the brain level.[iii]