Ashwagandha (Withania somnifera) has been used for human health in Indian traditional medicine.
Currently, there is intense research undertaken to understand the role and mechanism of ashwagandha in human health.
Some of the most relevant benefits of ashwagandha are discussed here.
1) Ashwagandha reduces stress and anxiety
Ashwagandha is an adaptogenic herb known for its anti-stress and anxiolytic properties (1).
Animal studies show that ashwagandha root extract is beneficial in fighting stress.
The rats fed with ashwagandha roots extract prepared in water were able to cope with cold swimming-induced stress better compared to placebo (2).
In humans, double-blind, placebo-control studies, show significant improvement in anxiety symptoms (3).
High cortisol levels are associated with stress and anxiety.
In a study, Individuals were given 300 mg (twice daily) of commercially available high concentration full-spectrum ashwagandha root extract called KSM-66.
The use of this supplement for 45 days was associated with a reduction in stress with low to mild adverse effects. Reduction in cortisol levels, as well as blood pressure, were also observed (4).
Another study in humans showed that the intake of 240 mg of a standardized ashwagandha extract (Shoden) once daily for 60 days significantly improved the stress and anxiety scores. It also resulted in low cortisol levels (5).
Shoden is a commercially available ashwagandha extract.
Research shows that ashwagandha is useful in reducing symptoms of stress and anxiety. Available data supports the idea of a reduction in stress due to a reduction in the level of cortisol.
2) Ashwagandha can improve athletic performance.
Ashwagandha can also be useful in improving physical and athletic performance.
The use of 300 mg of ashwagandha root extracts twice daily significantly improved cardiorespiratory endurance and quality of life in healthy athletic individuals compared to individuals who did not take the ashwagandha supplement (6).
Two studies tested the use of KSM-66 capsules in healthy athletic individuals.
The use of KSM-66 significantly improved quality of life, cardiorespiratory endurance, muscle strength, and muscle size compared to no use after physical exertion (7,8).
A meta-analysis of several studies shows that the ashwagandha supplementation was beneficial in improving athletic performance compared to no use.
Ashwagandha supplementation also increased testosterone levels in users compared to non-users (9).
Current studies indicate that ashwagandha supplementation can improve athletic performance and quality of life in healthy athletic individuals.
3) Ashwagandha may promote weight loss
Ashwagandha can be useful in combating weight gain as well as in weight management.
Studies in animals and humans have shown promising results.
Obese mice who consumed ashwagandha extract (1.25 mg per kg body weight per day) significantly reduced body weight compared to control. Moreover, food intake was significantly reduced in mice after ashwagandha extract consumption (10).
A similar study concluded that the use of ashwagandha extract helps with weight loss by thermogenesis (11).
There is evidence that ashwagandha extract use increases energy expenditure by improvement of mitochondrial function in obese mice. Thus, help in weight loss and control of obesity (12).
In a double-blind study, bodyweight management was significantly improved in individuals suffering from stress after the use of 300mg ashwagandha extract twice daily compared to the placebo (13).
These studies show that ashwagandha may help in weight loss and obesity control by increasing energy expenditure and promoting less consumption of food.
4) Ashwagandha use can improve sleep quality
Since ashwagandha is helpful in reducing stress it may also be useful for insomnia and sleep. In fact, the word “somnifera” means sleep-inducing.
Research shows that the use of ashwagandha significantly improved sleep quality. 300 mg twice daily use of KSM-66 capsules was effective in improving sleep quality (14).
A study with individuals suffering from insomnia showed a positive improvement in sleep efficiency and quality after the use of ashwagandha supplement without any adverse health effects. Hence resulting in better insomnia management (15).
Another randomized, double-blind, placebo-controlled study confirmed that the use of 300 mg of KSM-66 capsules twice daily for 10 weeks improved sleep quality test parameters (16).
In the elderly population between 65-80 of either gender, the use of KSM-66 capsules at 600 mg per day for 12 weeks improved sleep quality, general well-being, and mental alertness (17).
A meta-analysis of several studies reveals that ashwagandha use at 600 mg per day or more for more than 8 weeks improves sleep and alertness without any adverse effects on health (18).
The long-term adverse health effects of ashwagandha could not be determined in these studies.
Ashwagandha can be a useful supplement for better sleep and reducing symptoms of insomnia. However, studies with a large population size are needed to generalize the use of ashwagandha for sleep.
5) Ashwagandha can improve cognitive function and memory
Research shows that active ingredients from ashwagandha provide cognitive protection in rats with suppressed immunity and increased oxidative stress (19).
In humans, intake of ashwagandha supplements improved cognitive function in healthy individuals (20).
Another study focused on individuals with mild cognitive impairment. KSM-66 capsule use significantly improved memory.
Taking this supplement also improved executive function, attention, and information processing speed (21).
The ashwagandha extract was useful in recovering sensory/cognitive function in patients with schizophrenia by minimizing oxidative stress and neuroinflammation (22).
A randomized controlled trial in patients with bipolar disorder showed an improvement in condition with the use of ashwagandha extract tablets called Sensoril in addition to standard therapy (23).
A similar randomized, double-blind, placebo-controlled study in schizophrenia patients showed an improvement in condition with ashwagandha extract as adjunctive therapy (24).
Ashwagandha use is associated with better cognitive function and memory improvement. This effect is due to the anti-inflammatory and antioxidant properties of ashwagandha.
6) Ashwagandha may help with neurodegenerative diseases
Neurodegenerative diseases such as Alzheimer’s disease affect the elderly.
Ashwagandha has anti-inflammatory and anti-oxidant properties. Therefore, it may protect against brain dysfunction and Alzheimer’s disease.
Current evidence suggests that ashwagandha extract has the neuroprotective ability (25).
In rats, the use of ashwagandha leaf extract was able to significantly restore the BDNF levels and maintain synaptic plasticity (26).
Withaferin A and sitoindosides. VII–X, the active compounds from ashwagandha are able to reverse the Alzheimer’s disease indicators in animal studies (27).
Ashwagandha targets enzymes and pathways involved in the progression of neurodegenerative diseases such as Alzheimer’s disease. Therefore, efficiently minimize the effects of neurodegeneration (28,29,30).
Current animals studies are promising in showing that the extract of ashwagandha is useful in neurodegenerative disease. Extensive human studies are needed to fully understand the benefits of ashwagandha compounds in neurodegenerative diseases.
7) Ashwagandha has been used to improve male fertility
Ashwagandha has been used as an aphrodisiac for centuries. It was frequently recommended to treat male infertility in traditional medicine.
Animal research shows an improvement in spermatogenesis due to the testosterone-like effect of ashwagandha extract (31).
With age, testosterone levels decrease. The use of ashwagandha root extract (Shoden beads containing withanolide glycosides) use in older overweight males increased testosterone and DHEA-S levels.
DHEA-S helps with testosterone production (32).
However, this study did not find any improvement in vigor or sexual well-being after ashwagandha use.
The use of the ashwagandha may improve the semen quality in men with infertility issues after consumption of ashwagandha. The improvements were due to increased reproductive hormone levels (33).
One study found no improvement of psychogenic erectile dysfunction with the use of ashwagandha (34). Therefore, the effects of ashwagandha on the improvement of male fertility are purely physical.
Oxidative stress can negatively impact male fertility (35).
A meta-analysis of several studies shows that ashwagandha can improve male fertility by reducing oxidative stress. Oxidative stress reduction also improves overall well-being.
Moreover, ashwagandha improved semen quality as well as enzymatic activity in seminal plasma (36).
Another meta-analysis concluded that ashwagandha use is associated with significant improvement in male fertility, sperm count, sperm volume, sperm motility, and testosterone levels.
There was a significant decrease in oxidative stress. The ashwagandha use had no adverse effects on infertile men after treatment.
Although the observations are promising, more evidence is required to recommend the use of ashwagandha for male infertility (37).
Research shows that ashwagandha is useful in improving male fertility by increasing testosterone levels, increasing enzymatic activity, and decreasing oxidative stress. However, more research is needed for a robust conclusion.
8) Ashwagandha can lower blood glucose and may help with diabetes management
Animal research shows that ashwagandha roots and leaf extracts are both helpful in lowering blood glucose and serum lipid level (38).
The use of ashwagandha root extract in animal diabetes models significantly lowered glucose levels. An improvement in insulin sensitivity was also observed (39). Overall hypoglycemic effects of ashwagandha were observed.
Clinical research done in humans with mild Non-insulin-dependent diabetes mellitus (NIDDM) showed a decrease in blood glucose and cholesterol levels (40).
A meta-analysis of currently available research on the use of ashwagandha for diabetes concluded that the use of ashwagandha can be beneficial, however, the current sample size of several studies is low.
More studies, with robust controls, are needed to completely establish the use of ashwagandha for diabetes (41).
Ashwagandha may regulate blood glucose levels but research in humans is lacking strong evidence.
9) Ashwagandha has anti-inflammatory properties.
Chronic inflammation is detrimental to human health and leads to many diseases such as cardiovascular disease, diabetes, and even tumor.
Ashwagandha extract is shown to have anti-inflammatory properties (42).
Ashwagandha extract reduced inflammatory activity that in turn decreased arthritic effects in mice model of arthritis (43).
Ashwagandha extracts promote anti-inflammation by influencing the inflammation indicators such as IL-6, IL-8, and TNF‑α (44). Other studies have found similar results (45).
The anti-inflammatory property of Withaferin A compound extracted from ashwagandha has been widely reported.
Currently, the Withaferin A anti-inflammatory properties have been studied in disease models of diabetes, obesity, neurodegenerative disorders, cystic fibrosis, and osteoarthritis (46).
Therefore, by virtue of anti-inflammatory function ashwagandha can have great potential for human health.
There is strong evidence that ashwagandha has anti-inflammatory properties. So far Withaferin A of ashwagandha is identified as the main bioactive compound for this property.
10) Ashwagandha can be useful in alcohol addiction
Not many studies have explored this but preliminary studies show that ashwagandha can be beneficial in alcohol addiction.
The use of ashwagandha extract in animal models of alcohol addiction showed reduced alcohol dependence and withdrawal (47).
Another study found that ashwagandha was effective for alcohol withdrawal. Its effect was comparable to diazepam in alcohol withdrawal conditions (48).
An animal behavioral study for alcohol addiction showed that the use of ashwagandha was effective in minimizing motivation for drinking alcohol (49).
Currently, no robust human study exists to validate the results in animal studies.
There is preliminary evidence via animal studies that ashwagandha extract can be useful in reducing alcohol dependence and withdrawal.
11) Ashwagandha is effective in inhibiting tumor cells
Animal and cell-based research show that ashwagandha has antitumor properties.
The anti-tumor effect of ashwagandha has been known for many years (50).
Bioactive compounds of ashwagandha are responsible to inhibit the growth of the tumor cells.
For example, animal research shows that the Withaferin A extracted from ashwagandha significantly reduces the mammary tumor size and incidences of pulmonary metastasis.
Withaferin A is also effective against skin carcinogenesis as shown by animal studies (51,52,53).
Research indicates that Withaferin A directly kills tumor cells as well as modulates immune response (54).
Withaferin D isolated from ashwagandha has also been shown to kill tumor cells (55).
Ashwagandha leaf extract is also shown to have anti-cancer properties (56).
Moreover, ashwagandha leaf extract can selectively kill tumor cells (57).
Other studies have shown similar results with Withaferin A. It selectively kills tumor cells while leaving healthy cells intact (58).
This makes Withaferin A a very good candidate for anti-tumor therapy (59).
Ashwagandha compounds have anti-tumor properties. Current research from animal and cell-based studies is very promising.
Ashwagandha’s use in supplement form has been associated with a reduction in stress and anxiety symptoms.
Ashwagandha use is also beneficial in physical performance as well as male fertility. Ashwagandha has anti-inflammatory and antioxidative properties, therefore, it can help slow down the progression of chronic diseases.
Finally, ashwagandha use is associated with brain health.