A new international study led by researchers at Leiden University in the Netherlands has found that increasing atmospheric carbon dioxide is diminishing the nutritional quality of major food crops. While higher CO₂ levels may boost crop yields, the research shows a decline in essential nutrients such as zinc, iron, and protein, alongside a rise in toxic elements like lead. The findings suggest that foods are becoming more calorie-dense but less nutritious.

The decade-long study examined 43 crops, including rice, wheat, potatoes, and tomatoes, analyzing 32 key nutrients. On average, nutrient levels were found to drop by 3.2%, with zinc in chickpeas projected to fall by as much as 37.5%. Lead researcher Sterre Ter Haar described the results as “alarming,” noting that the changes could have serious health implications.

Experts warn that this nutrient decline may worsen global malnutrition, even as food production increases. The study highlights the need for urgent climate action and agricultural adaptation to preserve food quality as atmospheric CO₂ levels have already reached 425.2 parts per million.