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Randomized trial · measured the question itself

16-week trial in 30 Japanese adults with mild thinking problems found higher test scores

Mori and colleagues · Phytotherapy research : PTR · 2009

Original title: Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Points to benefit

At weeks 8, 12 and 16 the lion's mane group scored higher than placebo on a memory and thinking scale (HDS-R). At week 4 after stopping, scores fell. Lab tests showed no harmful effect.

The study at a glance

Type of study
Randomized trial
Who or what was studied
30 people · Japanese adults aged 50 to 80 with mild cognitive impairment
What was tested
Four 250 mg tablets, three times a day (3 g a day) for 16 weeks, vs placebo
What it measured
The question itself: memory and thinking
Daily amount
3 g a day
How long
16 weeks
Who has a stake
No disclosure in PubMed
No disclosure in PubMed.
Journal
Phytotherapy research : PTR, 2009
Source
PubMed record 18844328. This page is based on the abstract only.

How much this study counts

  • ✓Randomized: people were put into groups by chance, so the groups start out alike.
  • ✓Compared with a placebo, a dummy treatment.
  • –Small: 30 people. Small trials can miss real effects or find chance ones.
  • •Lasted 16 weeks.
  • ✓Measured the question itself: memory and thinking.
  • •The PubMed record has no conflict-of-interest statement.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

Each dot is one on-topic paper on this question. Steps near the top answer the question more directly.

↑ Stronger evidence

  1. Trials in people: memory and thinking

    4

    1 benefit, 3 mixed

    ↑ This study is the ringed dot

  2. Trials in people: other measures

    0

    None among the papers we read.

  3. Trials in people: lab tests or safety

    0

    None among the papers we read.

  4. Population studies

    0

    None among the papers we read.

  5. Blood levels and genes

    0

    None among the papers we read.

  6. Animals

    1

    1 no difference

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does lion's mane improve memory?”

Unclear. Only four trials, with mixed results.

Confidence: very low. Based on 6 on-topic papers.

Read the full answer

Of the other 3 papers on the same step: 3 mixed. This one found benefit. It differs from most of them.

  • Quoted in “What we found”: Only 14 papers exist on this question. Four are human trials of memory or thinking; the two that report size had 30 and 41 people.
  • Quoted in “What we found”: In 30 adults aged 50 to 80 with mild memory and thinking problems, 16 weeks of lion's mane tablets raised test scores above placebo. Scores fell after stopping.
  • Part of the finding “Longer trials: gains on some memory tests”.
  • Marked as a key paper in the research timeline: First human trial: 30 older adults, 16 weeks.
  • Open item for a person: Menon review Menon 2025 pooled one trial and one pilot trial; these may be Mori Mori 2009 or Saitsu Saitsu 2019. Check for double counting.
  • Open item for a person: Mori Mori 2009 and Saitsu Saitsu 2019 have no conflict statement in PubMed, so company ties are unknown.

Other papers on the same step

See all 6 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The reviewer corrected 2 fields after reading the abstract. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
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