Ashwagandha under fire: the dangers of dietary supplements

This month, the RIVM issued a damning assessment of nutritional supplements and tea containing the herb ashwagandha (from the shrub Withania somnifera). They could pose health hazards. Yet products containing ashwagandha could be found on the shelves for years. How is that possible? And why exactly is the herb dangerous?

The popularity surrounding ashwagandha

Ashwagandha plays an important role in traditional Indian medicine, Ayurveda. In fact, it is known as the king of herbs. Followers of Ayurveda believe it has rejuvenating properties. Ashwagandha is also said to have a supportive effect on stress.

In March 2023, ashwagandha became a hit on TikTok, reaching a young audience. According to influencers, the supplements are not only said to reduce stress, but also reduce sleep problems, stimulate memory and concentration and provide emotional stability. Nice promises, but are they true?

Are the benefits of ashwagandha proven?

While there are a few studies that seem to support some of the claims, the health claims of ashwagandha (and other herbs) supplements are not supported by science.

Individual studies say little, says Wieke van der Vossen. She is an expert in the field of food safety and labeling at the Nutrition Center. “To check whether the health claims are correct, they must be assessed by an independent body,” she explains. This noble task is given to EFSA, the European Food Safety Authority. This examines whether enough research has been done to confirm a health claim.

But that has gone a bit wrong in recent years, Van der Vossen knows. The EFSA received so many claims about nutritional supplements that the assessments on hold have been set. The organization simply hasn’t had time to look at it. ‘So nothing can be said about the possible health benefits of these supplements. So take the claims with a grain of salt.’

If it doesn’t help, then it does harm… sometimes it does

Such advice seems desperately needed, because the Dutch love nutritional supplements. Some stir a scoop of spirulina into their yogurt, others take a pill of scutellaria. Nearly six in ten adults have taken nutritional supplements in the past year. But they are not always as innocent as they seem. Especially herbal supplements.

‘Many people think that they do no harm because the ingredients come from nature. But that doesn’t mean anything. Natural things such as plants and herbs can also be very poisonous,’ says Van der Vossen. As examples, she mentions ephedra and kava kava, two supplements that can cause strokes and serious liver damage. They have been banned in the Netherlands for some time now.

Why isn’t more research done into the risks of supplements before they hit the market, just like with medications? ‘That is because nutritional supplements fall under the Commodities Act, just like food. That is less carefully examined than medicines,” says Van der Vossen. And that means that occasionally there are herbal products in stores that are less innocent than expected. Such as ashwagandha supplements and teas.

Dangers of ashwagandha

In December 2020, the Minister of Medical Care announced that the sale of nutritional supplements needed to be better regulated. “It appears that unsafe nutritional supplements are regularly sold that can cause health damage to users,” she wrote in a letter to the House of Representatives.

Since then, nutritional supplements have been subject to a risk assessment by the RIVM. In March 2024 it was ashwagandha’s turn.

Side effects such as drowsiness, stomach complaints and diarrhea were already known, but according to the government knowledge institute, ashwagandha can also pose more serious health risks. According to the RIVM risk assessment, too little research has been done to assess the long-term effects. But short-term studies show that ashwagandha use can cause excessive thyroid activity, as well as liver damage and suppression of the adrenal system. A few Dutch doctors have reported poisoning in people who took supplements containing the herb. Enough reason to be careful.

Abortion through ashwagandha
The RIVM is also concerned about the use of ashwagandha during pregnancies. In the past, the herb was used to induce abortions. No research has been done as to whether and at what dosage the herb actually causes termination of pregnancy.

What should you pay attention to when buying supplements?

So it’s better to leave ashwagandha alone from now on. Maybe the rest of the supplements too. ‘Most people do not need to take them at all, they already get sufficient nutrients by eating a varied diet,’ says Van der Vossen. Do you still want to take supplements? Then she has a few more tips:

• Buy supplements in a reliable store, such as a Dutch drugstore. The Dutch Food and Consumer Product Safety Authority only supervises products that go over the counter, not herbs that are offered online.
• Do not use herbal preparations (pills and powders with herbs as the main ingredient) during pregnancy. The effects of this have not yet been properly researched.
• Consult your doctor if you are taking medication. Some herbs in supplements do not mix well with certain medications.
• Do not exceed the daily dose.