Foraging and mental health: what the science actually says

Focus keyphrase: foraging mental health | nature connection wellbeing | wild food gut microbiome
Meta description: The science behind why foraging is good for your mind, your nervous system, and your gut — PubMed research on nature, cortisol, and microbiome diversity.

There is a version of foraging that is purely practical: you go out, you find plants, you come home with food. That version is real and valid. But most people who forage regularly will tell you that the food is almost secondary. What keeps them going back is something harder to name — the quality of attention it demands, the particular kind of quiet it produces, the way an hour in the hedgerow seems to reset something that an hour on the sofa simply does not.

It turns out that experience is not just anecdote. There is now a substantial body of peer-reviewed research documenting the physiological and psychological effects of nature immersion, green exercise, and plant diversity on human health. Foraging sits at the intersection of all three. Today, on the last Friday of the first week of April — with the hedgerows at their most generous — I want to look at what that research actually says.

What happens to your body when you walk in nature

The most consistent finding across nature and health research is the effect on cortisol — the body’s primary stress hormone. A 2021 scoping review in Frontiers in Public Health (PMC8001092) examined greenspace interventions across multiple study types and found consistent evidence that engaging with natural environments reduces both perceived stress and measurable cortisol levels. The effects were observed across age groups, health conditions, and types of nature exposure — from urban parks to woodland walks.

A 2024 systematic review and meta-analysis in Environment and Behavior (PMC11851813) went further, finding that nature exposure benefits human health across multiple domains: improved cognitive functioning, reduced anxiety and depression symptoms, lower blood pressure, and enhanced immune function. The review noted that effects were dose-dependent — more time in nature, stronger effects — and that active engagement with the environment (as opposed to passive observation) appeared to amplify the benefits.

Foraging is active engagement with the environment by definition. You are not walking through nature; you are attending to it at close range — reading the hedgerow, crouching to examine a leaf, noticing what has changed since last week. This is precisely the kind of focused, present-moment interaction with the natural world that the research associates with the strongest wellbeing effects.

Attention restoration: why foraging is cognitively different from other walks

Attention Restoration Theory, developed by psychologists Rachel and Stephen Kaplan and now supported by a substantial body of empirical research, proposes that natural environments have a specific restorative effect on directed attention — the effortful, conscious focus required for work, decision-making, and the management of daily life. A 2016 systematic review in Journal of Toxicology and Environmental Health (PMID: 27668460) examined the accumulated evidence and confirmed that exposure to natural environments consistently reduces mental fatigue and restores attentional capacity.

The mechanism proposed is “soft fascination” — the gentle, involuntary attention that a natural environment elicits. You notice a movement in the leaves, the shape of a flower, the particular colour of a new nettle tip. This kind of attention is effortless and therefore restful; it allows the directed attention systems to recover. Foraging intensifies this effect. When you are looking for something specific — the right leaf shape, the distinctive smell, the correct habitat — you enter a state of focused but relaxed attention that is quite unlike either passive rest or directed cognitive work. Many foragers describe it as the closest thing to meditation they have found that does not feel like meditation.

The immune system: forest bathing and NK cells

One of the most striking bodies of research on nature and health comes from Japan, where the practice of shinrin-yoku — forest bathing — has been studied in clinical settings since the 1980s. A landmark 2009 study in the International Journal of Immunopathology and Pharmacology (PMID: 19568839, Li et al.) sent participants on a three-day forest bathing trip and measured immune function before and after. The results were significant: forest bathing increased natural killer (NK) cell activity by 50%, increased the number of NK cells, and elevated intracellular levels of anti-cancer proteins — effects that were still measurable a month later.

NK cells are part of the innate immune system — the body’s first line of defence against viral infection and tumour development. The proposed mechanism involves phytoncides — volatile organic compounds released by trees and plants (particularly conifers, but also present in many hedgerow plants) — which appear to directly stimulate NK cell activity. A 2025 review in Preventive Medicine (PMID: 41718142) confirmed and extended these findings, noting that forest bathing is associated with modulation of inflammatory cytokine profiles and reduced markers of chronic stress alongside the NK cell effects.

You do not need a Japanese forest to access these effects. A hedgerow walk in Devon in April, crouching to pick wild garlic in a damp woodland, produces the same combination of phytoncide exposure, cortisol reduction, and present-moment attentional engagement that the research documents. The biology is the same.

Foraging and the gut microbiome: the 30-plant question

The relationship between plant diversity in the diet and gut microbiome health is now well-established. The American Gut Project — one of the largest citizen science microbiome studies ever conducted, published in mSystems in 2018 (PMC5954204) — found that people who ate more than 30 different plant species per week had significantly greater gut microbiome diversity than those eating 10 or fewer, regardless of whether they were omnivores, vegetarians, or vegans. Microbiome diversity is consistently associated with better metabolic health, improved immune function, and reduced inflammation.

A regular forager in spring naturally approaches or exceeds this 30-plant target without counting. A single hedgerow walk in April might yield wild garlic, nettles, hawthorn leaf tips, cleavers, dandelion leaves, wood sorrel, and gorse flowers — seven distinct plant species, each with its own unique fibre profile, polyphenol content, and prebiotic properties. Added to whatever you are already eating at home, a foraging habit is arguably the most effective and economical way to substantially increase plant diversity in the diet.

There is emerging research specifically on traditional forager populations and gut microbiome health. A 2024 study in Cell Reports examining the gut microbiome of Baka forager-horticulturalists found that greater access to and consumption of wild plant foods was associated with higher microbiome diversity and the presence of microbial taxa that are rarely found in industrialised populations — taxa associated with butyrate production, anti-inflammatory activity, and metabolic resilience. The wild plant food signal in the microbiome is measurable and distinct.

The mood dimension: nature connectedness and mental health

Beyond stress and immunity, there is a growing literature on the relationship between nature connectedness — a felt sense of belonging to and relationship with the natural world — and mental health outcomes. A 2025 review in PLOS ONE (PMC12466711) examining the effects of connectedness to nature on psychological wellbeing found consistent associations with lower depression scores, reduced anxiety, and higher life satisfaction across populations and age groups. The effect was not simply explained by time spent outdoors; the quality of connection — noticing, attending to, and feeling part of the natural world — was the active ingredient.

Foraging builds exactly this kind of connection. You begin to know your local landscape in a different way — not as backdrop but as a living system you are part of. You notice when the first hawthorn leaves appear, when the wild garlic reaches the woodland near the lane, when the elder is about to flower. This is the beginning of what ecologists call “ecological literacy,” and it appears to be genuinely protective for mental health — not through any mystical mechanism, but through the concrete, embodied experience of knowing where you are and what is around you.

What a foraging walk actually gives you

Put this all together and a foraging walk in April delivers, in a single hour or two:

• Cortisol reduction — measurable physiological stress recovery from greenspace immersion
• Attentional restoration — the soft fascination of looking for plants allows directed attention systems to recover
• Immune support — phytoncide exposure from plants and trees stimulates NK cell activity
• Microbiome diversity — multiple wild plant species, each with distinct fibre and polyphenol profiles
• Mood and meaning — nature connectedness, associated with reduced depression and anxiety
• Actual food — nutritionally dense wild greens to bring home and cook

No single wellness practice delivers all of these simultaneously. Foraging does, and it does it for free, in the landscape that is already around you.

What to look for on your walk this week

If you want to go out this weekend and experience this for yourself, here is what is at peak across the UK right now in early April:

• Wild garlic (Allium ursinum) — damp woodland floors and shaded hedgerows. Unmistakable garlic smell when a leaf is crushed. Leaves, flowers, and forming seed pods all edible.
• Hawthorn leaf tips (Crataegus monogyna) — emerging bright green from thorny hedgerow shrubs. Tender and slightly nutty. Eat raw in salads or wilt into soups.
• Nettles (Urtica dioica) — pick only the top 4–6 leaves with gloves. Still pre-flower across most of the UK. One of the most nutritionally dense wild greens available.
• Cleavers (Galium aparine) — the sticky weed on every hedgerow. Young tips are edible raw. Best as a cold infusion overnight.
• Dandelion (Taraxacum officinale) — leaves, flowers, and roots. Bitter leaves excellent in salads; flowers for dandelion honey or fritters.

⚠️ Safety reminder: Never eat any wild plant unless you are 100% confident in your identification. Wild garlic has toxic lookalikes (lily of the valley, Lords-and-Ladies) — always confirm the garlic smell before picking. If in doubt, leave it out. Take a good field guide; the Collins Complete Guide to British Wild Flowers and the Roger Phillips mushroom guides are reliable standards.

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References
Ewert, A. et al. (2021). Greenspace interventions, stress and cortisol: a scoping review. Frontiers in Public Health. PMC8001092
Mygind, L. et al. (2024). Systematic review and meta-analysis on the effect of nature on human health. Environment and Behavior. PMC11851813
Kaplan, S. (2016 review). Attention Restoration Theory: a systematic review of the attention restoration potential of exposure to natural environments. Journal of Toxicology and Environmental Health. PMID 27668460
Li, Q. et al. (2009). Effect of forest bathing trips on human immune function. International Journal of Immunopathology and Pharmacology. PMID 19568839
McDonald, D. et al. (2018). American Gut Project: plant diversity and microbiome diversity. mSystems. PMC5954204
Kaygusuz, O. et al. (2025). The effects of connectedness to nature on psychological wellbeing. PLOS ONE. PMC12466711

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If you would like to experience a foraging walk with guidance — learning to identify plants with confidence, understanding what is safe to pick, and coming home with a full basket — my spring foraging workshops run throughout April and May. And if you want to understand how wild plant nutrition fits into the broader picture of cellular health, hormonal balance, and biological age, that is exactly what we explore in The Cellular Reset programme.

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This content is for educational purposes only and does not constitute medical advice. Wild plants can be dangerous if misidentified. Never consume any wild plant unless you are completely confident in your identification. Some wild plants can interact with medications. Always consult your GP before using wild plants medicinally, particularly if you are pregnant, breastfeeding, or taking medication.

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