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As an adaptogen, ashwagandha may influence memory and cognitive function. One study evaluated the effect of 600mg of ashwagandha extract on memory and cognitive function in adults with mild cognitive impairment. When compared to placebo, the ashwagandha treatment group demonstrated significant improvements in both immediate and general memory as well as executive function, sustained attention, and information-processing speed (1).
Ashwagandha provides stress support.*
In a double-blind, placebo-controlled study, the Ashwagandha group showed a greater reduction in perceived stress than the placebo group.*
Scientists have noted a correlation between stress, increased cortisol levels and decreased physical activity. Stress can lead to increased caloric consumption, this, coupled with increased cortisol levels and decreased physical activity, can be blamed for stress related weight gain. The calming properties of Ashwagandha extract have been shown to reduce food cravings associated with stress. One study found that 600 mg of Ashwagandha extract (KSM-66) taken daily led to reductions in scores on the Food Cravings Questionnaire, a commonly used self-assessment which measures several domains of food cravings. The study group had statistically significant improvements in the following domains: planning to eat food, positive reinforcement from eating, relief from negative mood by eating, emotions that are involved during food cravings or eating, and environmental cues that may trigger food cravings (1).
Stress is the body's response to pressure. It can create a state of mental or emotional strain or tension, which can lead to underperformance or adverse clinical conditions. While there are many situations or life events that can cause stress, it is often triggered when we experience something new, unexpected or when we feel we have little control over a situation. Adaptogens are herbs that help in combating stress. Ayurvedic classical texts describe Ashwagandha as an adaptogen, and science has confirmed this.
A study on patients with chronic stress found that supplementing with Ashwagandha extract may help lower perceived stress and impact cortisol levels. Study participants took 600mg of Ashwagandha extract for 60 days and reported a 44% reduction in stress, compared to 5.5% in the placebo group. Serum cortisol levels were also lower in the study group with a 27.9% reduction in levels after 60 days (1).
The results of the above study were replicated in a second study that also looked at perceived stress and cortisol levels. Study participants were given 600mg of Ashwagandha extract daily and showed improvement in perceived stress and decreases in cortisol levels at 4 and 8 weeks (2).
A study that looked at the benefits of Ashwagandha extract on resistance training found that individuals who took 600mg daily had significant increases in muscle mass and strength. Compared to the placebo subjects, the group treated with Ashwagandha extract had significantly greater increases in muscle strength when completing a bench-press exercise and leg-extension exercise, and significantly greater muscle size increase at the arms and chest. Compared to the placebo subjects, the subjects receiving ashwagandha also had significantly greater reduction of exercise-induced muscle damage based on levels of serum creatine kinase. Serum creatine kinase is a commonly used measure of muscle damage because this protein is specific to muscle tissue. These findings suggest that Ashwagandha supplementation is associated with significant increases in muscle mass and strength and may be useful in conjunction with a resistance training program (1).
Another study investigated the effects of Ashwagandha extract on muscular performance during resistance training and found that men given 500mg for 12 weeks experienced significant improvements in average squat power, peak bench press power, 7.5 km time trial performance, and perceived recovery scores. No change was noted in the placebo group (2).
There is also evidence that supplementation with Ashwagandha extract can improve cardiovascular endurance by enhancing the amount of oxygen that is delivered to muscles. One study assessed cardiorespiratory endurance by measuring the oxygen consumption levels (VO2 max) of male and female adult athletes at peak physical exertion during a 20 m shuttle run test. The World Health Organization self-reported Quality of Life (QOL) questionnaire was also used to assess the study participants. The study found there was a greater increase from baseline in the mean VO2 max in the group supplementing with Ashwagandha extract ( KSM-66) compared to the placebo group at 8 weeks and at 12 weeks. They also noted that QOL scores significantly improved to a greater extent in the Ashwagandha group at 12 weeks compared to placebo. The findings suggest that Ashwagandha root extract enhances the cardiorespiratory endurance and improves QOL in healthy athletic adults.
Improving the amount of oxygen that is delivered to the muscles is a key factor in endurance training and performance. Maximal aerobic capacity (VO2 max), defined as the maximal amount of oxygen consumed during exercise, is dependent on the cardiorespiratory system for transporting oxygen to the muscles (1).
Research has shown that supplementing with Ashwagandha extract can improve maximal aerobic capacity (VO2 max). The first looked at the effects of 600mg of Ashwagandha extract on cardiorespiratory performance in athletes and found that study participants using Ashwagandha extract had significant increases in VO2 max as compared to placebo (2).