What are the neurological benefits of lion's mane?

Two menus side by side: what the marketing lists as neurological benefits, what the neurology clinic lists as measurable outcomes, and the matching of the first four items, which finds no measurement in a person for any of them

What are the neurological benefits of lion's mane is a question whose answer depends entirely on whose menu is being read, and the honest method is to put the two menus side by side. The marketing's menu, assembled from the tubs, the blogs and the podcasts, has five items: neurogenesis, the growth of new neurons; nerve regeneration, the regrowth of damaged peripheral nerves; myelin repair, the restoration of the insulating sheath around nerve fibres; neuroprotection, the defence of neurons against decline; and cognitive enhancement, a sharper mind. Beneath all five sits the mechanism the menu is built on, nerve growth factor raised by the mushroom's hericenones and erinacines. The neurology clinic's menu is a list of outcomes rather than benefits, each with an instrument: nerve conduction studies, which measure the speed and strength of signals along a peripheral nerve and are how regeneration after an injury is actually tracked; electroencephalography and evoked potentials, which measure the brain's electrical function; magnetic resonance imaging, which measures brain volume and, with the right sequences, myelin; validated clinical scales, which measure cognition and function in a way a clinician can score and compare; and, for growth factors and new neurons, cerebrospinal fluid sampling or post-mortem tissue, since neither can be read from blood. A neurological benefit, to the clinic, is a change on one of those instruments against placebo in a person, and the exercise of matching each marketing item to its instrument is the whole answer.

Neurogenesis first. The growth of new neurons in the adult human brain is measured only in post-mortem tissue, is debated even there, and cannot be measured in a living person by any method, so that a neurogenesis claim for a capsule is unmeasurable in the person taking it and has never been measured in anyone; the rodent studies that found more new neurons in a mouse hippocampus are the whole of the evidence, and a mouse is not a menu item. Nerve regeneration second. The instrument exists and is routine, the nerve conduction study, and no study of lion's mane in a human has ever run one; the regeneration claim rests on rodents with crushed sciatic nerves recovering faster in a few small studies, and on the fact that human nerves regrow at about a millimetre a day with or without a mushroom. Myelin repair third. The instrument is imaging, and no person taking lion's mane has had their brain or nerves imaged in a study; the claim rests on cell culture. Neuroprotection fourth. The instrument is a long trial against a defined decline, the kind run for dementia drugs over years, and none exists for the mushroom; the claim rests on rodents given a toxin and on the trophic protein story. Four items, four instruments, four empty columns, and beneath them a growth factor that has never been measured in the blood, spinal fluid or tissue of any human taking the mushroom.

The one item that matches, read precisely, what the clinic would and would not say about it, the honest one-line menu, and the honest buy

Cognitive enhancement is the fifth item on the marketing menu and the one that matches an instrument on the clinic's, because a validated cognitive scale is exactly what the clinic uses and exactly what the mushroom's one real trial used. Thirty Japanese adults aged 50 to 80 with a diagnosis of mild cognitive impairment took 3g a day of fruiting body powder in tablets or placebo for sixteen weeks, were scored on a cognitive scale every four weeks, and the lion's mane group separated from placebo at week eight, widened the gap at twelve and sixteen, and fell back toward placebo during a four-week washout. That is a neurological benefit in the clinic's sense: a change on a validated instrument, against placebo, in people. Read precisely, it is also a small one with conditions attached. The population was impaired, and the scale was built to detect impairment, so that healthy adults score at its ceiling and the finding may be undrawable in them; the trial was thirty people and has never been replicated at scale; the young-adult pilot that tried a healthy population found a faster Stroop test at 60 minutes that nobody felt and nothing after four weeks; and enhancement is the marketing's word for what the clinic would call a modest improvement on a screening scale in a diagnosed group. What the clinic would say about it is roughly this: one small positive trial in mild cognitive impairment, worth a larger trial, not a treatment, not evidence in healthy people, and not evidence for any of the other four items on the menu, which concern different tissues and different instruments.

The honest menu of neurological benefits is therefore one line long: a cognitive scale in a specific impaired population, on one trial, with the other four items never measured in a person and the growth factor beneath them never measured in a human. A lifter reading the five-line menu on a tub should know that four of the lines have no instrument behind them in anyone and that the fifth has one trial in a population they are probably not in, and should know what the clinic's instruments do find for the nervous system a lifter actually has: sleep consolidates motor skill by around a fifth overnight on the motor learning tasks; the nerves a lifter damages are compressed at the elbow, wrist, shoulder and hip and are tracked by conduction studies and fixed by taking the pressure off; and the register's nervous system sentence belongs to eleven nutrients, B12 and magnesium among them, as deficiency statements, and to no fungus. The honest buy is a mushroom bought on the one-line menu by a lifter who wants to run the one trial's clock on themselves with an instrument that has headroom: the worked example, {FLLM}, a stated 5:1 fruiting body extract labelled 1500mg mushroom equivalent per capsule, 120 days for £15.49 at 13p, UK made, independently lab tested, with no neurological benefit on the label because the law permits none and the clinic's menu, honestly read, holds one.

What to check on the label

Questions people also ask

Does lion's mane cause neurogenesis in humans?

Nobody can know, because adult human neurogenesis is measured only in post-mortem tissue, is debated even there, and cannot be measured in a living person by any method; the neurogenesis claim rests on rodent studies in which mice given lion's mane grew more new hippocampal neurons, and a claim that is unmeasurable in the person taking the capsule is not a benefit the clinic can recognise, however often the tub prints it.

Does lion's mane regenerate nerves?

No human study has run the instrument that would show it, the nerve conduction study, and the claim rests on rodents with crushed sciatic nerves recovering faster in a few small studies; human peripheral nerves regrow at about a millimetre a day after injury with or without a mushroom, nerve growth factor itself failed as a human nerve repair drug in the 1990s, and the lifter's compressed nerves at the elbow, wrist, shoulder and hip are tracked by conduction studies and fixed by taking the pressure off.

What is the proven neurological benefit of lion's mane?

One, on a validated cognitive scale: thirty Japanese adults aged 50 to 80 with mild cognitive impairment taking 3g a day of fruiting body powder scored higher than placebo from week eight to sixteen and fell back in a four-week washout; it is small, in a diagnosed population, on a scale healthy adults top before any intervention, never replicated at scale, and accompanied in healthy young adults by an unfelt Stroop signal at 60 minutes and nothing after four weeks; it is the whole of the clinic-recognised list.

Is lion's mane neuroprotective?

The instrument that would show it, a long trial against a defined decline of the kind run for dementia drugs over years, has never been run for the mushroom; the claim rests on rodents given a toxin and on the nerve growth factor story, and nerve growth factor has never been measured in the blood, spinal fluid or tissue of any human taking lion's mane; neuroprotection is a word on the marketing menu with no entry on the clinic's.

Does lion's mane raise nerve growth factor in humans?

It has never been measured: the hericenones and erinacines raise nerve growth factor synthesis in cultured cells and in rodent brains, but no human study has sampled blood, cerebrospinal fluid or tissue for the protein in anyone taking the mushroom, and growth factors in the brain cannot be read from a blood test in any case; the mechanism beneath every item on the marketing menu is, in people, an untested hypothesis, and the one benefit that has been measured stands on its own without it.

Sources

1. The adult human neurogenesis literature: whether new neurons form in the adult human hippocampus is measured only in post-mortem tissue and remains debated, no method exists to measure neurogenesis, nerve growth factor in the brain or synaptic growth in a living human taking a supplement, so that any neurogenesis claim for a capsule is unmeasurable in the person taking it. PubMed record
2. Mori K, Inatomi S, Ouchi K, Azumi Y, Tuchida T. Improving effects of the mushroom Yamabushitake (Hericium erinaceus) on mild cognitive impairment: a double-blind placebo-controlled clinical trial. Phytotherapy Research 2009;23(3):367-372. PubMed record
3. The recombinant nerve growth factor clinical trial literature: subcutaneous nerve growth factor was tested in human diabetic and HIV neuropathy in the late 1990s, with a large phase three trial failing to show benefit and injection-site pain and hyperalgesia the characteristic effects, so that raising nerve growth factor has not translated into a human nerve repair treatment even when the protein itself was given. PubMed record
4. The peripheral nerve regeneration literature: after injury, axons regrow at roughly one millimetre a day in humans, recovery depends on the injury's type, distance to target and the person's age and glycaemic control, and surgical repair, time and rehabilitation are the interventions with evidence; animal models of nerve crush are the setting for most compound studies. PubMed record

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