Soil health and human health: what connects them?

There is a growing body of research suggesting that the condition of our soils is closely linked to patterns of human health. Not in a simplistic or deterministic way, but through slow, systemic pathways that connect soil biology, food quality, microbial exposure, and long-term resilience.

At the same time, we are witnessing two parallel trends. Globally, soil health indicators are declining. Soil organic matter is being lost, biological diversity is narrowing, and soils are becoming more compacted and chemically simplified. Alongside this, rates of chronic, non-communicable diseases such as type 2 diabetes, cardiovascular disease, inflammatory conditions, and some autoimmune disorders continue to rise.

These trends are not identical, and one does not mechanically cause the other. But research increasingly suggests that they are connected through the food system and through our changing relationship with living ecosystems.

This post explores what the evidence actually shows, where the limits of that evidence lie, and why soil regeneration matters for human health without overstating claims or promising quick fixes.

Soil is a living system

Modern soil science no longer treats soil as inert matter. Healthy soil is a living system made up of minerals, organic matter, water, air, and vast communities of bacteria, fungi, protozoa, nematodes, and insects. A single teaspoon of biologically active soil can contain billions of microorganisms.

These organisms perform essential functions. They cycle nutrients, build soil structure, regulate water, suppress pathogens, and support plant growth. When soils lose biological diversity, these functions weaken.

Large-scale reviews of soil science research consistently show that intensive agricultural practices focused on chemical inputs and yield optimisation reduce soil organic matter and microbial diversity over time. This loss affects how nutrients are stored and released, how plants interact with microbes, and how resilient food production systems are to stress.

At Generation Soil, this understanding underpins everything we do. We treat soil as a living partner, not a substrate. You can read more about this approach on our approach to soil as a living system.

From soil to food quality

One of the most robust links between soil health and human health runs through food quality rather than direct exposure.

Meta-analyses and long-term studies show that soils with higher organic matter and biological activity tend to support crops with more stable mineral uptake and, in some cases, higher concentrations of certain micronutrients. While nutrient content is influenced by many factors including crop variety and climate, degraded soils are consistently associated with reduced nutrient density and greater reliance on external inputs.

Several large reviews have also highlighted how simplified soils can affect plant secondary metabolites. These compounds are not calories or vitamins, but they play roles in plant defence and, when eaten, interact with human metabolic and inflammatory pathways.

Over the past fifty years, dietary patterns have shifted towards energy-dense but nutrient-poor foods. During the same period, agricultural soils have lost an estimated one third to one half of their original organic matter in many regions. Researchers increasingly argue that these trends should be analysed together rather than separately.

This does not mean that soil regeneration alone will reverse chronic disease. But it does suggest that soil degradation is part of a wider pattern of nutritional simplification.

Microbial diversity and the immune system

Another emerging area of research focuses on microbial exposure.

Human immune systems evolved in close contact with diverse environmental microorganisms. A number of interdisciplinary reviews link reduced exposure to environmental microbial diversity with increased incidence of allergies, asthma, and autoimmune conditions. This idea is sometimes described as the biodiversity or old friends hypothesis.

Urbanisation, soil sealing, chemical management, and reduced contact with living soils have all narrowed the range of microbes people regularly encounter. Studies comparing children raised in environments with greater exposure to soil, animals, and diverse vegetation show more resilient immune responses than those raised in highly sanitised settings.

Healthy soils are a major reservoir of microbial diversity. When soils are biologically degraded, that diversity contracts. When soils are regenerated, microbial communities become more complex and stable.

This does not mean that handling soil is a medical intervention. It does mean that living soils form part of the background ecological conditions within which human immune systems develop.

Our workshops and composting programmes are designed to rebuild this everyday contact carefully and safely. You can explore how this works in practice through our soil education workshops.

Chronic disease as a systems issue

Non-communicable diseases are often framed as individual lifestyle problems. Diet, exercise, stress, and genetics are all important. But public health researchers increasingly emphasise that these conditions are shaped by food systems, environments, and long-term exposure rather than isolated choices.

Global health commissions have highlighted how industrial food systems, soil degradation, ultra-processed diets, and environmental stressors interact to create vulnerability. The rise in metabolic and inflammatory diseases has occurred alongside a narrowing of diets and a distancing from ecological processes.

Seen through this lens, soil health is not a cure, but a foundational condition. Regenerating soils supports more resilient food systems, which in turn support dietary diversity, nutrient stability, and ecological buffers against shock.

This framing aligns with the One Health perspective, which treats human, animal, and environmental health as interconnected rather than separate domains.

Decline, disconnection, and what regeneration offers

The decline in soil health did not happen overnight. It emerged from systems designed for speed, control, and short-term output. The health consequences of those systems are similarly slow and cumulative.

Regeneration works on the same timescale. Building soil organic matter, restoring microbial communities, and rebuilding local nutrient cycles takes years, not months. The benefits are distributed rather than dramatic.

At Generation Soil, we focus on community-scale practice because it allows people to see and participate in these cycles directly. Composting is not waste disposal. It is a way of returning nutrients to soil, rebuilding biology, and closing loops locally.

If you want to understand how this works in Bristol, you can read about the Bristol Living Compost Project or explore related reflections in our blog on soil and regeneration.

Staying grounded

It is tempting to claim that soil regeneration will fix human health. The evidence does not support that kind of certainty, and we avoid making it.

What the research does support is a quieter, more grounded conclusion. Healthy soils underpin healthy food systems. Healthy food systems support human resilience over time. When soils degrade, those foundations weaken.

Regeneration is not about purity or perfection. It is about rebuilding relationships between kitchens, compost, soil, and communities in ways that are visible, participatory, and realistic.

That is the work we are doing. Slowly, locally, and with care.

Key papers and reports

Soil health and nutrient density

Montgomery, D.R. & Biklé, A. (2021). Soil Health and Nutrient Density: Beyond Organic vs Conventional Farming. Frontiers in Sustainable Food Systems.

A widely cited review showing how practices that build soil organic matter and biological activity are associated with improved micronutrient and phytochemical content in crops.

Long-term soil management and nutrient cycling

Drinkwater, L.E. et al. (1995). Fundamental differences between conventional and organic agroecosystems in nutrient cycling and soil biology. Ecosystems.

A landmark long-term study demonstrating how organic matter management reshapes soil biology and nutrient stability over time.

Soil microbiomes and human health

Rook, G.A.W. et al. (2017). Microbial ‘old friends’, immunoregulation and socioeconomic status. Clinical & Experimental Immunology.

Explores links between reduced environmental microbial exposure, immune dysregulation, and modern patterns of inflammatory disease.

Systems framing: soil, food, and health

Whitmee, S. et al. (2015). Safeguarding human health in the Anthropocene epoch. The Lancet Commission on Planetary Health.

Establishes the case for understanding human health outcomes as inseparable from environmental and food system integrity.

How to read these

These papers point to long-term patterns and system relationships, not simple cause-and-effect claims. Together, they support the idea that soil health underpins food quality and ecological resilience, which in turn shape the conditions for human health over time.