Can Healthier Soil Put More Nutrition Back Into Our Food?

Evidence suggests the nutrient content of some staple crops has declined over recent decades, prompting researchers to investigate whether regenerative farming could help reverse the trend.

The food on our plates may not deliver the same nutritional value it once did, with historical data pointing to substantial declines in certain vitamins and minerals across several widely consumed crops.

Figures cited in a new Guardian investigation suggest that, by the late 1990s, the vitamin C content of lemons had fallen by almost a third over 22 years, while calcium in carrots had declined by more than a quarter and vitamin A in bananas by 57%. The mineral content of wheat has reportedly dropped by between 20% and 30% since the 1960s.

Several possible causes have been proposed. Modern crop varieties have frequently been bred to grow more quickly and produce higher yields, potentially diluting their nutrient concentrations. Rising atmospheric carbon dioxide can also encourage plants to produce more sugars and starches while accumulating fewer nutrients.

Now, researchers are examining whether regenerative agriculture — an approach centred on rebuilding soil health, increasing biodiversity and restoring natural ecosystems — could offer part of the solution.

Striking differences recorded

Research involving Francesca Brkic and the University of Lincoln compared produce from regenerative and conventional farms. Samples reportedly contained up to 22 times more iron in kale, eight times more selenium in dried peas and significantly higher folate levels in carrots grown using regenerative methods.

For the research, regenerative farms were characterised as those using practices including cover cropping and livestock grazing, while avoiding ploughing, insecticides and other pesticides. However, the absence of a universally agreed or certifiable definition of regenerative agriculture remains an important limitation.

Scientists supporting the approach argue that repeated ploughing and intensive chemical use can disrupt the complex fungal and microbial networks within soil. These networks help plants access nutrients that would otherwise remain unavailable.

A separate small-scale US study published in 2022 also identified an association between regenerative practices and greater nutrient density in crops. Meanwhile, a multi-year study by the Bionutrient Institute, involving thousands of samples, found that soil biological activity and overall soil health had the strongest positive relationship with nutritional value.

Previous research into organic production has produced similarly encouraging findings. A Newcastle University review published in 2015 concluded that switching to organic fruit, vegetables and cereals could provide additional antioxidants equivalent to consuming between one and two extra portions of fruit and vegetables each day.

Evidence remains mixed

Despite the promising results, scientists have not reached a consensus.

Reviews undertaken by UK and French food standards bodies found some nutritional differences between production systems but concluded that these were generally small. A large Stanford University review found that certain organic foods contained higher quantities of minerals and nutrients — particularly phosphorus — but said the findings varied considerably and were sometimes statistically insignificant.

Regenerative agriculture also faces questions about cost, labour requirements and its ability to operate at sufficient scale. Because it can rely less heavily on machinery and agrochemicals, it may require more human labour, potentially making production more expensive.

Some researchers have also warned that regenerative claims are vulnerable to greenwashing without clear definitions or independent standards. Health professionals, meanwhile, caution that consumers should not assume sustainably produced food is so nutrient-rich that they can eat less of it. Encouraging people to consume sufficient quantities and variety of fruit and vegetables remains the priority.

There is also continuing scientific debate over whether regenerative systems could reliably feed a global population of more than eight billion while delivering their promised environmental benefits.

Nevertheless, the emerging evidence points towards a potentially important connection between healthy soil, resilient farming and the nutritional quality of food. Further large-scale, standardised research will be essential to establish how significant that connection is — and whether regenerative practices can deliver consistent benefits across different crops, climates and production systems.

What is already increasingly clear is that soil health is not simply an environmental concern. It may also play a crucial role in determining the quality of the food reaching consumers’ plates.