ANALYSIS: Ashwagandha supplements might reduce stress and improve other parts of life – but it’s too early to say

Researched by Kirsten Cosser

This report was written by Africa Check., a non-partisan fact-checking organisation. View the original piece on their website.

According to the World Health Organization, the Covid-19 pandemic has led to a 25% increase in cases of anxiety disorders in many countries across the world. 

An article, originally from local South African newspaper Greytown Gazette and republished in March 2022 by News24, discussed this recent rise in mental health problems. It suggested some “healthy habits” South Africans could adopt to help cope with anxiety and stress. 

The article quoted “integrative health coach” Laura Johnston, who recommended a particular herbal health supplement, Bio-Shoden Ashwagandha. The article did not mention that Johnston was also the marketing director of Coyne Healthcare, a supplement and vitamin company that sold this particular product. 

The article went on to claim that ashwagandha plant extract, the key ingredient in the supplement, had been proven to “support emotional health by reducing cortisol levels (stress hormones in the body), improve sleep and cognition, and boost immunity”.

Ashwagandha and ayurvedic medicine 

Ashwagandha (Withania somnifera, also called winter cherry) is a woody evergreen shrub that has long been used as a medicine in India. The plant is found in various parts of India, Sri Lanka, China, the Middle East and Africa. Medicines made from the plant usually contain dried root extracts, though the leaves, seeds, fruits and flowers are also sometimes used. 

Ashwagandha has traditionally formed part of ayurveda, an Indian system of traditional medicine that dates back over 3,000 years. The system centres around a holistic approach to health, incorporating lifestyle, diet and exercise, combined with herbs and other substances. 

The Indian government under prime minister Narendra Modi has sought to revive this system of traditional medicine. In 2014, it founded the ministry of ayurveda, yoga, unani, siddha and homoeopathy. Responsible for promoting these practices, the ministry's annual budget was reported to have tripled to US$290 million between 2014 and 2020.   

In South Africa, ayurveda is considered a complementary system of medicine, with multiple centres dedicated to its practice. Scientific research into ayurvedic medicines and practices varies widely in method and quality, but some benefits are supported by some preliminary studies.

Ashwagandha is one of the plants used in ayurveda that has become particularly popular in recent years. A quick internet search yields scores of adverts for ashwagandha-containing supplements, along with numerous blog posts and website entries encouraging its use. 

Globally, the market for ashwagandha-containing products is predicted to grow at an annual rate of 11%. According to the same market research, South African demand for ashwagandha for use in pharmaceutical products is also growing. 

Historically, ashwagandha has been used  as a treatment for a host of maladies, from insomnia and anxiety to fainting, constipation and pimples. We looked into the claims that ashwagandha reduces cortisol, improves sleep and cognition, and boosts immunity. Is any of this supported by scientific evidence?

Ashwagandha, cortisol and stress 

In recent years, a substantial amount of research has been published looking into the potential health benefits of ashwagandha. Some of this has focused on the plant’s potential in helping alleviate stress and anxiety symptoms. Early research focused on studies in animals and cell models, but more recent studies have begun to look at ashwagandha’s effects in human participants. 

Such studies vary in quality, but some have been randomised controlled trials (RCTs), considered the gold standard of scientific research. A recent review looked at six of these studies, which were conducted in India. 

The studies varied somewhat in how they were conducted and who the participants were. For instance, some looked at effects on healthy participants, and others at people diagnosed with an anxiety disorder or experiencing chronic stress. In all studies, researchers gave participants supplements containing ashwagandha extracts, but in varied doses. Most studies were conducted over eight weeks. 

The researchers in these studies measured stress levels using various self-report surveys as well as the participants’ levels of cortisol. Cortisol is a hormone often used in research to gauge levels of stress someone is experiencing. Higher cortisol concentrations indicate higher stress levels. In most of the trials, the supplements did reduce cortisol and perceived stress symptoms, compared with placebo. 

The trials also showed reductions in anxiety and stress symptoms measured by self-report surveys.

Africa Check spoke with Adrian Lopresti, one of the authors that conducted this review, to learn more. Lopresti is a psychologist and researcher at Australia’s Murdoch University, and his research focuses on integrative treatments for mental health problems. 

Lopresti was optimistic about the results in these studies that found ashwagandha reduced cortisol, but also cautioned that “more research is required because some of the studies were not high quality”. 

Overall, Lopresti said that the strongest evidence we had around ashwagandha was in relation to stress and anxiety, “possibly by reducing cortisol concentrations”. 

But he also explained that since the vast majority of research took place in India, “it is important that studies be conducted across more diverse populations and countries”. 

Ashwagandha and sleep, cognition and immunity

Another review was conducted of studies that investigated the effect of ashwagandha extracts on sleep. Five RCTs were included, and overall they found that there was a small but statistically significant effect on sleep. This effect was more pronounced in people diagnosed with insomnia, where the dosage was at least 600mg per day over at least eight weeks. In relation to the available evidence, Lopresti said the results were promising, but that again, more research needed to be done. 

The effects of ashwagandha on cognition is another area that is beginning to be studied. A small pilot study of 50 people with mild cognitive impairment showed some improvement in memory and related cognitive functioning after receiving a supplement daily over eight weeks. Some other early studies have also been conducted with promising results. But again, Lopresti said, more research was needed. 

Finally, in relation to immunity, the research also seems to be promising but preliminary, with research in this area largely confined to animal studies. 

So should I take ashwagandha supplements? 

It seems that the ancient plant medicine may have potential to alleviate some symptoms of psychological distress, especially when it comes to stress and anxiety. But it is important to temper this optimism with some points around the body of research and the process of approving medicines. 

First, as Lopresti pointed out, the majority of research into ashwagandha has been conducted in India. When research is only conducted in one location, it becomes difficult to generalise results and determine whether the same results would apply to people in other places. For the same reason, far more research is also needed that involves larger sample sizes. 

It is also worth noting that the dosages used in this research vary considerably from study to study, making it difficult to determine what dosage would have a particular effect, if any.

In South Africa, ashwagandha is not approved as a medicine by the South African Health Products Regulatory Agency (Sahpra). The product packaging for the version encouraged in the News24 article reads: “This unregistered medicine has not been evaluated by Sahpra for its quality, safety or intended use.”

For something to be registered as a medicine, it must undergo rigorous testing on large groups of people in multiple phases. This is to ensure that it is effective, but also that it is safe for different groups of people. 

Since ashwagandha products have not undergone this procedure, it is too early to say whether the supplement is either effective in treating any illness, or whether it is safe to use. You can learn more about the process of approving medicines here. 

Africa Check spoke with Dr Pieter Cohen, medical doctor and associate professor at Harvard Medical School in the US. Cohen has published extensively about herbal and other health supplements. He said that “health claims on supplements do not need to be supported by any evidence that the product actually works”. As such, people should be cautious when purchasing these products. 

Ashwagandha may interact with other medications and supplements. It can also produce side effects, like vomiting, drowsiness and blood pressure changes. It is also unclear whether pregnant or breastfeeding people should take ashwagandha. In general, it is always best to speak to a medical doctor before taking supplements or medications.

This report was written by Africa Check., a non-partisan fact-checking organisation. View the original piece on their website.