Functional Mushrooms and Biological Age: What Lion’s Mane, Reishi, and Turkey Tail Actually Do

Mushrooms occupy an unusual position in nutrition science. They are neither plant nor animal — they belong to their own kingdom entirely, with a biochemistry that has no direct equivalent anywhere else in the food supply. And because of that, they contain compounds that you genuinely cannot get from anything else you eat.

The research on medicinal and functional mushrooms has accelerated significantly in the past five years. The mechanisms are becoming clearer, the human trial data is building, and for women navigating perimenopause — where cognitive clarity, immune resilience, and biological age are all live concerns — several of these compounds are directly relevant. This is an honest look at what the evidence actually shows.

What makes mushrooms different

Three categories of compound set mushrooms apart from other foods.

The first is beta-glucans — polysaccharides found in the cell walls of fungi that act as immunomodulators. They bind to receptors on immune cells including macrophages, natural killer cells, and dendritic cells, activating and regulating immune response without overstimulating it. Beta-glucans from mushrooms are structurally distinct from the beta-glucans in oats: the (1→3)(1→6)-β-D-glucan configuration found in fungi is the form with the strongest immune-signalling evidence.

The second is ergothioneine — a sulphur-containing amino acid found almost exclusively in fungi, which the body transports via a dedicated transporter (OCTN1) expressed most densely in tissues under highest oxidative stress: the liver, kidneys, bone marrow, and brain. Ergothioneine is a potent intracellular antioxidant, and blood levels decline measurably with age. A 2024 review in the Journal of Fungi by Luo et al. identified ergothioneine depletion as a meaningful contributor to the oxidative stress component of biological ageing — and mushrooms as the primary dietary source. Read the review here.

The third category is species-specific bioactives: the hericenones and erinacines in lion’s mane, the triterpenes in reishi, the betulinic acid and inotodiol in chaga, and the polysaccharide-K (PSK) in turkey tail. Each acts through distinct mechanisms — which is why the most thoughtful approach to mushroom supplementation looks at a combination rather than a single species.

Lion’s mane and the brain fog question

Brain fog in perimenopause is among the most distressing and underacknowledged symptoms, and lion’s mane (Hericium erinaceus) is the functional mushroom with the most direct cognitive mechanism.

The relevant compounds are hericenones (from the fruiting body) and erinacines (from the mycelium). Both have been shown in laboratory studies to stimulate the synthesis of nerve growth factor (NGF) — a protein essential for the growth, maintenance, and survival of neurons. Hericenones C, D, E, and H stimulate NGF gene expression through the protein kinase A signalling pathway. Erinacine A has been shown to increase NGF levels in brain tissue and promote neurogenesis.

The human clinical evidence is more modest than the laboratory findings — as is typical in nutritional neuroscience — but it is positive. A 2023 randomised controlled trial published in Nutrients and reviewed in a 2024 PMC analysis found that lion’s mane supplementation was associated with improved speed of cognitive performance and reduced subjective stress in healthy adults. The authors were appropriately cautious about effect sizes and noted that larger, longer-duration trials are needed. Read the study here.

What makes lion’s mane particularly relevant to perimenopause specifically is the oestrogen-NGF connection. Oestrogen upregulates NGF synthesis and expression of its receptors in the brain — which is one of the mechanisms by which oestrogen supports cognitive function. As oestrogen declines, this neuroprotective signal weakens. Lion’s mane works on the same NGF pathway through a different mechanism, providing a food-based input to a system that is losing one of its hormonal drivers.

This is not a replacement for hormone therapy where that is appropriate. But it is a meaningful dietary lever, and the mechanistic rationale for its use in this life stage is more grounded than most supplements that get attached to the perimenopause conversation.

Reishi, turkey tail, and immune modulation

The immune system in perimenopause shifts in ways that are not always visible but are clinically significant. The decline in oestrogen is anti-inflammatory in some respects but also associated with increased innate immune activation and a higher baseline inflammatory tone — sometimes described as inflammageing — which is one of the mechanisms through which biological age accelerates during this transition.

Reishi (Ganoderma lucidum)

Reishi has the longest history of documented medicinal use of any functional mushroom, and its triterpene compounds — ganoderic acids — have the most direct anti-inflammatory mechanism. They inhibit the NF-κB signalling pathway, which governs the expression of pro-inflammatory cytokines including TNF-α and IL-6. These are exactly the cytokines elevated in the low-grade chronic inflammation associated with biological age acceleration.

Reishi also has an established effect on sleep quality — a clinical trial found that 1,800mg of reishi extract daily significantly improved sleep time and sleep efficiency in study participants. In perimenopause, where sleep disruption drives a cascade of downstream effects on cortisol, inflammation, and cognitive function, this is not a trivial finding.

Turkey tail (Trametes versicolor)

Turkey tail contains polysaccharide-K (PSK) and polysaccharide peptide (PSP), which are the best-evidenced beta-glucan compounds in the entire mushroom pharmacopoeia. PSK is licensed as an adjunct cancer treatment in Japan — the only mushroom compound to reach that regulatory threshold. In the context of healthy ageing rather than cancer treatment, turkey tail supports the innate immune response and has been shown to positively modulate the gut microbiome, increasing Bifidobacterium and Lactobacillus species — which directly connects to the estrobolome function covered in the estrobolome post.

Chaga (Inonotus obliquus)

Chaga has the highest ORAC (oxygen radical absorbance capacity) value of any food tested — it is, by that measure, the most antioxidant-dense substance in the human diet. The relevant compounds include betulinic acid, inotodiol, and melanin-based pigments that scavenge reactive oxygen species with particular efficiency. Given that oxidative stress is a primary driver of the epigenetic alterations and cellular senescence that underpin biological age acceleration — as the Journal of Fungi review confirms — a concentrated dietary source of antioxidant compounds is directly relevant to any biological age protocol.

How to eat more mushrooms

Before supplements, food. Shiitake, oyster, maitake, and cremini mushrooms are widely available, inexpensive, and contain meaningful amounts of beta-glucans and ergothioneine. The ergothioneine content is highest in oyster and king oyster varieties. Cooking increases bioavailability rather than reducing it — heat breaks down the chitin cell walls that would otherwise limit absorption.

Aim for 80–100g of mushrooms three or more times per week as a starting point. Sauté in a little olive oil with garlic, add to grain bowls, stir into soups, or roast alongside other vegetables. They are one of the most versatile and umami-forward ingredients in a perimenopause-focused kitchen.

For lion’s mane and the more pharmacologically active species — reishi, chaga, turkey tail — the concentrations achievable through food alone are lower than those used in clinical studies, and the species are not always easy to source fresh. This is where a well-formulated supplement becomes relevant.

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Sources

• Luo J, Ganesan K, Xu B. Unlocking the Power: New Insights into the Anti-Aging Properties of Mushrooms. J Fungi (Basel), 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC10970926/
• Docherty S, et al. The Acute and Chronic Effects of Lion’s Mane Mushroom Supplementation on Cognitive Function, Stress and Mood in Young Adults. Nutrients, 2023. https://pmc.ncbi.nlm.nih.gov/articles/PMC10675414/
• Friedman M. Chemistry, Nutrition, and Health-Promoting Properties of Hericium erinaceus. J Agric Food Chem, 2015.
• Wachtel-Galor S, et al. Ganoderma lucidum (Lingzhi or Reishi): A Medicinal Mushroom. In: Herbal Medicine: Biomolecular and Clinical Aspects. 2nd edition.

This article is for general information and is not medical advice. Please consult your GP or a registered practitioner before starting any new supplement.