Lion’s mane mushroom for cognitive function and stress reduction Original paper

In this randomized controlled study, lion’s mane didn’t improve processing speed in the short term or reduce subjective stress in the longer term (compared to placebo); in fact, there was evidence that it may even worsen short-term and long-term memory.

The acute (short-term) and chronic (long-term) effects of lion's mane mushroom on cognitive function.

The primary outcomes were attention, executive function, working memory, and episodic memory.

43 adults (average age of 26; 23 men and 20 women) who didn’t have any chronic diseases.

In this randomized controlled study, the participants supplemented with 600 mg of lion’s mane mushroom (Hericium erinaceus) or a placebo for 4 weeks.

At baseline, the participants completed cognitive and mood assessments before and 60 minutes after consuming the first dose of lion’s mane or placebo (acute study). This procedure was repeated at the end of the study (i.e., after 4 weeks of supplementation; chronic study).

The cognitive assessment comprised the following tests: immediate and delayed word recall, numeric working memory, choice reaction time, the Stroop task, peg and ball, and delayed word recognition. Mood and psychological state were measured using the Stress Visual Analog Scale (S-VAS), Visual Analog Mood Scales (VAMS), and the Perceived Stress Scale (PSS).

In the acute study, lion’s mane improved performance on the Stroop task, indicating faster processing speed. However, compared to placebo, performance for immediate word recall was worse following lion’s mane — the participants had fewer correct responses and more errors during the test.

After 4 weeks of supplementation, the participants in the lion’s mane group reported lower levels of subjective stress (S-VAS) compared to the placebo group, but delayed word recall accuracy was worse in the lion’s mane group compared to the placebo group.

A potential explanation for the lack of a significant effect on most of the tests is that the participants were cognitively healthy — lion’s mane may only improve performance in older adults or individuals with cognitive conditions like Alzheimer’s disease and mild cognitive impairment.^[1][2]