Climate change is making our food less nutritious

We hear a lot about how climate change affects food production, especially in terms of crop yields. But a growing body of research points to a quieter, less visible threat: the nutritional quality of our food is changing – and not for the better.

New findings from researchers at Liverpool John Moores University suggest that rising levels of CO2 and hotter temperatures are altering the chemistry of common crops. The result? Plants may look healthy and grow fast, but they’re packing fewer essential nutrients.

That has major implications for public health, especially in countries already battling food insecurity and chronic diseases.

Testing vegetables for tomorrow

“Our work looks beyond quantity to the quality of what we eat,” said Jiata Ugwah Ekele, a PhD student at Liverpool John Moores University.

Ekele’s research focuses on how environmental stressors – from increased carbon dioxide to rising temperatures – change the nutritional makeup of food crops.

Her team grows popular leafy vegetables like kale, rocket, and spinach inside climate-controlled chambers at the university. Researchers adjust the CO2 levels and temperatures to reflect the UK’s future climate projections.

“These environmental changes can affect everything from photosynthesis and growth rates to the synthesis and storage of nutrients in crops,” said Ekele.

Tracking plant activity

The research takes a closer look at what’s happening inside the plants. Scientists track photosynthetic activity as the plants grow, using chlorophyll fluorescence and quantum yield measurements

At harvest, the team measures yield and biomass, then runs chemical tests to see what nutrients are present.

Using high-performance liquid chromatography and X-ray fluorescence, they analyze sugars, proteins, flavonoids, vitamins, and antioxidants.

Bigger crops, fewer nutrients

The early data shows that crops do grow bigger under higher CO2 levels. But that doesn’t mean they’re healthier.

“After some time, the crops showed a reduction in key minerals like calcium and certain antioxidant compounds,” Ekele said.

And when heat is added to the mix, things get worse. According to Ekele, the interaction between CO2 and heat stress has complex effects – the crops do not grow as big or fast and the decline in nutritional quality intensifies.

One surprising twist in the results was that not all vegetables responded the same way. Some showed sharp declines in nutrients, while others were more resilient.

“This diversity in response highlights that we can’t generalize across crops. This complexity has been both fascinating and challenging and reminds us why it’s important to study multiple stressors together,” Ekele said.

Crops may fuel disease

A key concern is what happens when crops lose essential nutrients. Elevated CO2 can increase the sugar content in fruits and vegetables – but it often lowers levels of protein, vitamins, and minerals.

“This altered balance could contribute to diets that are higher in calories but poorer in nutritional value,” Ekele said.

“Increased sugar content in crops, especially fruits and vegetables, could lead to greater risks of obesity and type 2 diabetes – particularly in populations already struggling with non-communicable diseases.”

When people eat food that lacks protein, iron, calcium, or other essential nutrients, it can weaken their immune system and worsen existing health conditions. This hits hardest in low- and middle-income countries where food choices are limited.

“It’s not just about how much food we grow, but also what’s inside that food and how it supports long-term human well-being,” said Ekele.

Food systems face global stress

Even though the study simulates future UK climate conditions, the findings echo far beyond British borders.

“Food systems in the Global North are already being challenged by shifting weather patterns, unpredictable growing seasons, and more frequent heatwaves,” noted Ekele.

“In tropical and subtropical regions, these areas also contend with overlapping stressors such as drought, pests, and soil degradation – and are home to millions who depend directly on agriculture for food and income.”

Ekele hopes this work inspires more research and cross-disciplinary collaboration. She said that food is more than just calories – it’s a foundation for human development and climate adaptation.

Connecting plant science to broader issues of human well-being is essential, especially as the climate changes and nations work toward building a food system that supports not just productivity, but also health, equity, and resilience.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–