The link between healthy soil and a healthy body

Williamson pivoted to human health and nutrition after 15 years working as a vet, studying at King’s College London. There, immersed in the thinking of professor of genetic epidemiology Tim Spector, she learned about the vital role of the human microbiome – the bacteria, fungi and viruses that inhabit our intestines and underpin overall health. Besides bolstering our immune system, this vast, microbial ecosystem breaks down dietary fibre and synthesises essential vitamins, all while crowding out harmful, disease-causing bacteria.

It’s a similar picture in healthy soils, where bacteria and fungi help to unlock nutrients for plant roots. “When farmers aren’t using pesticides, crops have to build their own, natural pest repellents,” explains Williamson, whose book, Soil to Gut, is out this summer. “They do that by making more plant nutrients called polyphenols, and that process depends on soil microbes.”

Human diets rich in polyphenols – a type of antioxidant – have been linked to reduced risks of cancer, heart disease, type 2 diabetes and Alzheimer’s. “They’re rocket fuel for our gut microbes,” Williamson says. “Those microbes then produce vitamins and thousands of beneficial compounds, which impact our health beyond our gut. They balance blood cholesterol and help manage inflammation in the body, which we know contributes to so many modern-day chronic conditions.”

Diets rich in polyphenols – a type of antioxidant – are rocket fuel for our gut microbes

The idea that healthy soils might nurture healthy people isn’t new. In the early 1900s, English botanist and pathologist Sir Albert Howard – a leading light of the then nascent organic farming movement – was working as an agricultural adviser in India when he noticed a pattern. Traditional Indian farming practices produced healthier soils than conventional systems back in his UK homeland. Crops were abundant. Livestock and villages thrived.

Despite today’s resurgence in regenerative farming, modern science has yet to prove a definitive causal link between soil and human health – but it’s catching up. One study, published in the British Journal of Nutrition, found that polyphenols in organically grown fruit and veg could be as much as 60% higher than in non-organic equivalents.

Meanwhile in the Netherlands, a ‘food pharmacy’ initiative run by HarvestCare, a company bridging the gap between regenerative farming and healthcare, has been ‘prescribing’ organic food boxes to type 2 diabetes patients. The results of an independent study of HarvestCare’s work by researchers at Leiden University are due later this year, but anecdotal evidence suggests patients have seen health improvements.