The worrying trend of declining nutrient levels in everyday foods has sparked concerns about the long-term impact on public health. Research from the US Department of Agriculture in the late 1990s revealed alarming declines: vitamin C in lemons fell by nearly a third, calcium in carrots dropped by over a quarter, and vitamin A in bananas plummeted by 57%. Similarly, the mineral content of wheat has seen a 20-30% reduction since the 1960s. These findings have prompted questions about how we can reverse this trend and improve the nutritional value of our food.
Several factors have contributed to this decline, including the development of high-yielding crop varieties and rising atmospheric carbon dioxide levels. Plants grown in these conditions tend to produce more sugars and starches at the expense of nutrients. While some solutions like genetically modified crops and synthetic soil amendments have been proposed, a growing number of agricultural researchers are championing regenerative agriculture as a more natural and potentially effective remedy.
Regenerative agriculture focuses on rebuilding organic matter and fostering healthy ecosystems within the soil. In stark contrast to conventional farming methods that often disturb and deplete soil health, this approach aims to promote soil's natural ability to produce nutrients. Initial findings from studies like that of Francesca Brkic at the University of Lincoln are promising: iron levels in kale from regenerative farms were found to be up to 22 times higher than conventionally grown samples, while selenium in dried peas was eight times higher, and folate in carrots showed an astonishing increase of up to 20,000 times.
The distinction between regenerative and organic farming is crucial. While organic standards focus on avoiding harmful practices, they do not explicitly mandate positive soil-building actions. Regenerative farms, as defined in Brkic's study, typically employ cover crops, integrate grazing animals, and abstain from ploughing or using synthetic insecticides and pesticides. This approach aims to restore the soil's natural mycorrhizal networks, which are vital for plants to absorb nutrients effectively.
Dr. David Montgomery, a US geologist and co-author of 'What Your Food Ate', highlights the importance of regenerative agriculture in correcting the damage inflicted by conventional farming practices that prioritised yield over soil health in the post-war era. He likens the microbial ecosystem disrupted by these methods to essential 'truckers and miners' of nutrients, which can be brought back by treating soil as a living ecosystem.