Summary
Davis (2009) synthesises evidence from food composition databases and earlier analyses — including the author's own prior work — to argue that the nutrient density of many food crops has declined measurably over the latter half of the twentieth century. The paper attributes much of this change to a 'dilution effect', whereby breeding for higher yields results in crops that accumulate proportionally less mineral and other micronutrients per unit of fresh weight. Published in HortScience, the review contextualises these trends within broader debates about soil health, varietal selection, and the nutritional adequacy of modern diets.
UK applicability
Although the primary datasets drawn upon are North American (chiefly USDA), comparable analyses using UK food composition tables have yielded broadly similar findings, making the paper's conclusions relevant to UK agricultural and public health policy debates, particularly around soil fertility management and crop breeding priorities.
Key measures
Nutrient concentrations (minerals, vitamins, protein) in crop produce; comparisons across historical USDA and UK food composition datasets; yield trends
Outcomes reported
The paper examines evidence for declining concentrations of minerals, vitamins, and other nutrients in food crops over several decades, exploring probable causes including dilution effects associated with higher-yielding cultivars and changes in agricultural practice.
Topic tags
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