by Marion Nestle
Jul 1 2024

Industry-funded study of the week: Ashwagandha

I saw this one in a newsletter:

Ashwagandha intake linked to memory and attention benefits: Acute and repeated supplementation with liposomal ashwagandha may boost select cognitive effects, including memory, attention, vigilance and reaction time in healthy adults, says a new study…. Read more

The study: Leonard, M.; Dickerson, B.; Estes, L.; Gonzalez, D.E.; Jenkins, V.; Johnson, S.; Xing, D.; Yoo, C.; Ko, J.; Purpura, M.; et al. Acute and Repeated Ashwagandha Supplementation Improves Markers of Cognitive Function and MoodNutrients 2024, 16, 1813.

Background: “Ashwagandha has been reported to reduce stress and attenuate cognitive decline associated with inflammation and neurodegeneration in clinical populations. However, the effects as a potential nootropic [cognitive-enhancing] nutrient in younger populations are unclear.”

Method:  59 men and women were given either a placebo or ashwagandha and given various cognitive function tests at baseline and one month.

Results: Ashwagandha supplementation improved acute and/or 30-day measures of various tests.

Conclusion: “Results support contentions that ashwagandha supplementation (225 mg) may improve some measures of memory, attention, vigilance, attention, and executive function while decreasing perceptions of tension and fatigue in younger healthy individuals.”

Funding: “The Human Clinical Research Facility at Texas A&M University received a fee-for-service award from Specnova LLC (Tysons Corner, VA, USA) in collaboration with Increnovo LLC (Whitefish Bay, WI, USA). Members of the Exercise & Sport Nutrition Lab collected and independently analyzed the data. Specnova was not involved in data collection, analysis, or manuscript writing.”

Comment: This is your typical industry-funded study with a title triggering my standard question: Who paid for this?

Specnova’s mission: “Sourcing new, concentrated bioactives from the world’s most fertile regions, and applying the latest technologies for yielding an expanded scope of health claims. Our difference is your competitive edge.”  Increnovo “offers consultancy to the nutritional supplement and food and beverage industries in the following areas: Research and development, Pioneering of new ingredients and products, New technologies, and Guidance in the areas of product marketing and distribution.”

Like most dietary supplements, this one is said to perform miracles.  Also like most supplements, the evidence for those miracles ramains weak.

The NIH Office of Dietary Supplements says

Several randomized, placebo-controlled clinical trials, most of them fairly small in size and of short duration, have found that ashwagandha may reduce perceived stress and anxiety and improve the quality and duration of sleep [6,7,31]. Because studies have used various ashwagandha preparations (with different extraction and standardization processes) and doses, it is difficult to identify specific extracts or recommended amounts [6,32]…In addition, ashwagandha may have potential adverse effects on the liver and thyroid and might not be safe for people with prostate cancer or those who are pregnant or nursing.

The National Center for Complementary and Integrative Health says:

  • Research shows that some ashwagandha preparations may be effective for insomnia and stress. However, evidence is unclear about its effects on anxiety.
  • There is some limited evidence that suggests that taking ashwagandha for 2 to 4 months may increase testosterone levels and sperm quality.
  • There isn’t enough evidence to determine if ashwagandha is helpful for any other health conditions, such as asthma, athletic performance, cognitive function, diabetes, menopause, and female infertility.
  • There is not enough high-quality evidence suggesting that ashwagandha is helpful in treating COVID-19.

When it comes to supplements, evidence is not the issue.  Belief is what matters.  The mere suggestion that a supplement might work is all it takes to convince people to buy it.  And if nothing else, supplements have powerful placebo effects.  We could all use some of those these days.