As climate change transforms our planet, a quieter shift may be happening on our plates. While we often hear about extreme weather and crop shortages, new research suggests the nutritional value of everyday vegetables — particularly leafy greens — may also be at risk.
In a study presented at the Society for Experimental Biology’s annual conference this week, scientists reported that rising carbon dioxide (CO₂) levels and warmer temperatures could lead to lower nutrient concentrations in vegetables like spinach, arugula (also known as rocket) and kale.
The work comes from a research team at Liverpool John Moores University, where PhD student Jiata Ugwah Ekele is studying how climate stressors affect plant nutrition. In a controlled lab setting, her team grew vegetables under projected future climate conditions for the UK — with higher CO₂ levels and elevated temperatures. Using precise chemical analysis, they measured concentrations of key compounds like proteins, minerals, antioxidants and flavonoids.
While higher CO₂ initially encouraged faster growth, it came at a cost.
“After some time, the crops showed a reduction in key minerals like calcium and certain antioxidant compounds,” Ekele said.
Adding heat made things worse. Crops exposed to both high CO₂ and heat grew more slowly and experienced an even greater decline in nutritional quality.
That matters because leafy greens are some of the most nutrient-dense foods in the human diet. A drop in antioxidants, protein or essential minerals could have wide-reaching effects, from weakened immune function to a higher risk of chronic disease. According to Ekele, this shift could be especially concerning for people already struggling with diet-related conditions such as obesity, type 2 diabetes or nutrient deficiencies.
The study also found that not all crops responded the same way. Some greens were more sensitive than others, suggesting that variety — both in agricultural systems and in individual diets — may help buffer against nutrient loss. Still, the trend raises concern. As Ekele puts it, “It’s not just about how much food we grow, but what’s inside that food and how it supports long-term human well-being.”
Although the research is still in its early stages and has not yet been published in a peer-reviewed journal, it adds to a growing body of evidence that climate change is not only a food supply issue but a nutrition issue, too. Other studies have shown similar reductions in protein, iron and zinc in staple crops like wheat and rice when grown under elevated CO₂.
So what can you do today? Supporting local and seasonal agriculture may help ensure fresher, more nutrient-rich produce. Eating a wide variety of fruits and vegetables can help reduce reliance on any single crop. And promoting sustainable food systems — those that prioritize biodiversity and climate resilience — can help protect nutrition on a broader scale.
“We have to think holistically about the kind of food system we’re building — one that not only feeds us, but nourishes us,” Ekele said. “Food is more than just calories; it’s a foundation for human development and climate adaptation.”