Monitoring the Mineral Content of Plant Foods in Food Composition Databases

Declines in the mineral content of food have been reported in several countries. This study monitored reported changes in the mineral content of plant foods in Australian food composition databases between 1991 and 2022. Commonly consumed plant foods (n = 130), grouped as fruit, vegetables, legumes, grains, and nuts in raw unprocessed form, were matched between three reference databases from 1991, 2010, and 2022. Absolute and percentage differences in mineral content (iron, zinc, calcium, and magnesium) were calculated. During this 30-year period, 62 matched foods had updated mineral content. Iron content decreased significantly for fruit (48%) and vegetables (20%), although absolute differences were small (0.09–0.14 mg/100 g). Zinc content declined by 15% for fruit (<0.1 mg/100 g, absolute difference 0.03 mg/100 g), but no differences were observed for calcium and magnesium content. Potential reasons for any reported differences could not be explored using food composition data alone, likely due to biological, agricultural, and/or analytical factors. Nutritionally, these small differences are unlikely to have a major impact on the population’s nutritional status, although efforts to improve fruit and vegetable consumption are encouraged to meet recommendations.