Ashwagandha is considered to be a traditional stress reliever. It is also being investigated for its potential to enhance memory and immune function. But what does the science say about all its purported health benefits and are any supported by solid evidence? Read on to find out!
Potential Benefits of Ashwagandha
1) Stress
Of all of the potential benefits of ashwagandha, this has the most robust body of evidence to support it, but it hasn’t been approved by the FDA! It’s important to talk to your doctor before taking ashwagandha for any reason.
Ashwagandha is traditionally used as a tonic to calm the nerves. In two studies of 116 chronically-stressed people, the root extract improved stress, well-being, and happiness; it also reduced cortisol levels [2, 3, 4].
In a study of 39 people, ashwagandha extract was slightly effective for people with anxiety. Although these results are promising, the effectiveness of ashwagandha in people with anxiety remains to be determined in larger, better-designed trials [5].
In several animal studies, Ashwagandha was helpful against anxiety and depression and for improving stress tolerance [6, 7, 8, 9, 2].
2) Memory
Ashwagandha root extract improved memory in 50 people with mild cognitive impairment. The extract also improved working memory in another study of 53 people [10, 11].
In rats, Ashwagandha protected against memory impairment due to PTSD and the lack of oxygen (hypoxia) [12, 13].
3) Weight Loss & Muscle Growth
Ashwagandha root extract reduced food cravings, eating, and body weight in a study of 52 people [3].
In three studies with over 100 people, ashwagandha extract in combination with resistance training [14, 15, 16]:
- Reduced body fat
- Increased muscle strength
- Boosted testosterone
4) Endurance
In a trial of 49 healthy athletic adults, Ashwagandha extract improved endurance and self-reported physical health after 12 weeks [17].
It had the same effect on 40 elite cyclists after 8 weeks of supplementation [18].
5) Diabetes
In a small trial of 12 people, Ashwagandha decreased blood sugar levels as effectively as diabetes medication, without significant adverse side effects [19].
In other animal studies, Ashwagandha reduced the severity of complications from diabetes, such as testicular dysfunction, cataracts, and nerve pain. Supplementation also improved antioxidant status; this is helpful because excess glucose creates oxidative stress [24, 25, 26, 27].
6) Heart Health
Ashwagandha is believed to reduce blood pressure and cholesterol and prevent atherosclerosis, thus improving heart health, but clinical evidence is limited. In one human trial, adding ashwagandha to conventional anti-ischemic drugs improved outcomes compared to the conventional treatment alone [22, 28, 29].
In animal studies, Ashwagandha reduced the risk of stroke and heart attacks. It also decreased triglyceride levels and protected against oxidative damage due to chemotherapy [30, 31, 32].
7) Infections
Antibacterial Activity
In a study of 133 people with tuberculosis, Ashwagandha and other herbals in combination with antibiotics relieved coughing and fever better than antibiotics alone. In another study of 99 people with tuberculosis, Ashwagandha improved symptoms, inflammation, and body weight [33, 34].
In mouse and cell studies, Ashwagandha has inhibited or killed bacteria such as Salmonella and Staphylococcus aureus [35, 36, 37].
Antiviral Activity
An herbal remedy containing Ashwagandha sped up recovery from viral hepatitis in 29 patients [38].
Ashwagandha has also shown antiviral activity against HIV, herpes, and Infectious Bursal Disease virus in cell-based studies [39, 40, 41, 42].
Ashwagandha inhibited the growth of multiple species of fungus (Aspergillus flavus, Fusarium oxysporum, and Fusarium verticillioides) in a cell study [36].
Anti-Parasitic Activity
Ashwagandha has shown anti-parasitic activity against Leishmania and Malaria in animal studies [43, 44, 45].
8) Symptoms of OCD & ADHD
OCD
In a study of 30 people with obsessive-compulsive disorder (OCD), Ashwagandha extract taken with standard treatment reduced their symptoms more than medication alone [46].
Ashwagandha also effectively treated the symptoms of OCD in mice [47
9) Schizophrenia
In a pilot trial of 11 people, Ashwagandha reduced the severity of sensory problems experienced by schizophrenia patients [50, 51].
However, it did not help with feelings of isolation or depression in another study of 25 schizophrenic patients [52].
10) Pain
Ashwagandha reduced pain, stiffness, and disability in 60 people with knee joint pain. Ayurvedic treatment containing ashwagandha reduced pain, joint tenderness, and swelling in a study of 86 people with rheumatoid arthritis [53, 54].
In another study of 42 people, an herbal mixture containing Ashwagandha, Indian frankincense, turmeric, and zinc reduced pain from osteoarthritis. Ashwagandha also relieved pain in three rodent studies [55, 56, 57, 58].
11) Reproductive Health
Women
Ashwagandha may reduce the complications of menopause. In a trial of 51 menopausal women, ashwagandha reduced symptoms such as hot flashes, mood fluctuations, sleep issues, irritability, and anxiety [59].
In 50 healthy women, Ashwagandha improved self-reported measures of sexual function [60].
Men
In a clinical trial of 150 men, Ashwagandha reduced oxidative stress, increased testosterone, and lowered FSH. These hormonal changes encourage the production of new sperm cells. It also improved sperm count and mobility [62].
In 46 men with low sperm count, Ashwagandha increased [63]:
- sperm count, by 167%
- semen volume, by 53%
- sperm motility, by 57%
It recovered semen quality in 180 infertile men [64].
12) Sleep
The root or whole plant extract has been used as a sleep agent in Ayurveda. A mouse study found that triethylene glycol is the active component of Ashwagandha responsible for sleep induction [65].
Ashwagandha improved sleep quality in 6 out of 18 healthy people. It also improved sleep in rats through activating the GABA pathway [66, 67].
Sleep loss is unhealthy and leads to increased levels of reactive oxygen species (ROS) and cell death in the brain. Interestingly, Ashwagandha prevented the negative effects of sleep deprivation in rodents, likely through antioxidant mechanisms [68, 69, 70].
13) Immunity
In a small trial of 5 people, Ashwagandha extract improved the immune response by activating white blood cells. In two other trials (a total of 142 people), an herbal mix containing Ashwagandha increased the activity of natural killer cells, white blood cells specialized to fight tumors and viruses [71, 72].
In mice, Ashwagandha extract enhanced immunity by activating bone marrow cells, macrophages, and lymphocytes [73, 74].
It increased the levels of Th1 cytokines and prevented the depletion of white blood cells in stressed mice [75, 75].
Finally, in a combined mouse and cell study, Withaferin A inhibited the activity of myeloid-derived suppressor cells (MDSCs). These dysfunctional immune cells can stimulate tumor growth and prevent the immune system from attacking cancer cells [76, 77].
14) Adrenal Function
Congenital adrenal hyperplasia (CAH) is an inborn dysfunction of enzymes that control hormone production in the adrenal gland. It results in a deficiency of cortisol and aldosterone and an excess of male hormones. Symptoms include excess facial hair, acne, hair loss, menstrual irregularity, and infertility.
In two case studies, Ashwagandha improved the symptoms and hormone levels of elderly women with CAH [80, 81].
15) Oxidative Stress
Withanolides, the Ashwagandha active compounds, are potent antioxidants. In a study on human cells, Ashwagandha improved markers of age-related oxidative stress (FOXO3A and SIRT3), suggesting it may prevent premature aging [82].
In rat studies, Ashwagandha boosted the body’s antioxidants, including superoxide dismutase (SOD), catalase, and glutathione. It also prevented kidney injury due to dehydration and oxidative damage due to chemotherapy [83, 84, 85].
Longevity Studies
Ashwagandha’s antioxidant properties may potentially increase longevity. It increased the antioxidant enzymes and reduced markers of oxidative stress in a study of 30 people [86].
In three studies, Ashwagandha extended the lifespan of a worm (C. elegans) often used to study models of longevity [87, 88, 89].
16) Brain Health
In cell studies, Ashwagandha promoted the growth of brain cells and stimulated neuronal regeneration [90, 2].
Ashwagandha can reduce oxidative damage from drugs and protect against excess glutamate. It helped control epileptic seizures in mice and treat dyskinesia (involuntary movement) in rats [91, 92, 93, 94, 95].
Alzheimer’s Disease
Alzheimer’s disease is a form of dementia caused by deposits of beta-amyloid proteins and loss of brain cells. Ashwagandha improved cognitive function and reduced beta-amyloid deposits in mouse models of Alzheimer’s [96, 97].
Parkinson’s Disease
Parkinson’s disease is a neurodegenerative disease involving progressive loss of dopamine neurons. In a mouse model of Parkinson’s, Ashwagandha normalized dopamine levels and reduced free radical damage to brain cells [98, 99].
Huntington’s Disease
Huntington’s disease is a genetic disorder that causes oxidative damage and a progressive breakdown of brain cells [100].
In rat studies, Ashwagandha protected against oxidative stress and mitochondrial dysfunction, suggesting it could be useful in diseases such as Huntington’s [100, 101, 102].
17) Bone Health
Bone health issues often arise after menopause, when low levels of estrogen disrupt bone structure. In mice with estrogen deficiency, Ashwagandha prevented bone loss and stimulated new bone formation [103, 104].
It improved bone building in calcium-deficient rats and chickens and increased bone collagen in arthritic rats [105, 106, 107, 108].
In cell studies, Ashwagandha stimulated bone formation and protected cartilage [109, 110].
18) Kidney Damage
In rat studies, Ashwagandha protected the kidneys against toxicity of several chemicals, including:
- Bromobenzene (toxic chemical) [111]
- Carbendazim (antifungal) [112]
- Gentamicin (antibiotic) [113, 114]
- Lead (heavy metal) [115]
- Streptozotocin (chemotherapy) [116]
It also protected against kidney damage caused by dehydration [84].
19) Liver Health
Ashwagandha protected the liver against damage from radiation and heavy metals in rats [117, 118].
It increased the bile content in rats with high cholesterol and decreased certain liver enzymes that indicate tissue damage [30, 119].
20) Respiratory Health
Polysaccharides extracted from Ashwagandha suppressed coughing in guinea pigs as effectively as codeine [120, 121].
In baby rats, withaferin A also protected the lungs against inflammation and oxidative stress caused by toxic bacterial lipopolysaccharides (LPS). Future trials will clarify whether Ashwagandha or its compounds may be helpful against respiratory infections [122].
21) Autoimmunity
Lupus is an autoimmune disease that involves high levels of inflammation. In a mouse study, Ashwagandha reduced inflammatory markers that tend to be high in lupus and other autoimmune diseases, including IL-6 and TNF-alpha [123, 124].
22) Morphine Dependence
Ashwagandha may help prevent people from developing a dependence on morphine, and it may help people who are already dependent wean themselves off of morphine without severe withdrawal symptoms [127].
In a rat study, Ashwagandha extract reduced withdrawal symptoms and prevented morphine dependence. In neurons exposed directly to morphine, Ashwagandha extract prevented the downregulation of opioid receptor activity. Thus, Ashwagandha may be useful to prevent dependence when opioid painkillers are necessary [128, 129, 127].
23) Mild Hypothyroidism
Mild hypothyroidism, or low thyroid hormones, occurs in 3-8% of people and is especially common in women over 55. Treatment with levothyroxine, a synthetic form of the thyroid hormone T4, often comes with more risks than benefits; thus, many people with mild hypothyroidism go untreated [130].
In a trial of 50 people with mild hypothyroidism, Ashwagandha extract normalized TSH and thyroid hormones (T3 and T4) [131].
It also increased thyroid hormones in hypothyroid rodents and reduced oxidative stress and inflammation [132, 132, 133].
24) Cancer Research
Ashwagandha improved fatigue and quality of life in a trial of 100 cancer patients receiving chemotherapy [134].
Several animal and cell studies have shown that the constituents of Ashwagandha, in particular withaferin A, inhibit or destroy cancer cells [135, 2, 136, 137].
What’s more, Ashwagandha can make the chemotherapy drug paclitaxel more effective against lung cancer, according to mouse studies [138, 139, 140].
In cell and animal studies, Ashwagandha has slowed or reversed the growth of several cancers, including:
- Brain [141, 142]
- Breast [143, 144, 145]
- Cervical [146, 146]
- Colon [147, 142]
- Kidney [148]
- Lung [2, 149]
- Lymphoma [150]
- Ovarian [2]
- Pancreatic [151]
- Prostate [142, 152]
- Skin [153, 154, 155, 2]
- Stomach [156]
Takeaway
Ashwagandha is a versatile traditional herb that’s traditionally thought to relieve anxiety and stress. Its active components have been investigated for cognitive and emotional benefits; they may also help manage neurological conditions from Alzheimer’s to schizophrenia, but more research is needed.
The antioxidant properties of ashwagandha are hypothesized to protect the liver, lungs, brain, and kidneys. It may also prevent hormonal imbalances and improve sexual function in both men and women, but larger trials are required to verify its effectiveness and safety.
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