Environmental factors driven by climate change are already shaping what ends up on Americans’ plates and how nutritious it is, according to a new perspective paper by researchers at the University of California, Irvine’s Joe C. Wen School of Population & Public Health.

Rising carbon dioxide levels, extreme weather events, air pollution and shifting ecosystems are disrupting food production and supply chains, often in ways that make healthy food harder to find or afford. The paper examines how these forces may quietly erode the nutritional quality of everyday foods, from grains to fruits and vegetables, with consequences for long-term health.

As crops are damaged by floods, heat waves and droughts, and as environmental conditions alter the nutrient content of staple foods, communities – especially those already facing food insecurity – may be at greater risk of nutrient deficiencies. The authors assert that this raises urgent questions about whether dietary supplements could help fill emerging nutrition gaps or support health during environmental stress.

“Environmental change is not only an ecological issue. It’s a nutrition and public health issue,” said Margaret Nagai-Singer, first author of the paper and a research fellow in Wen Public Health. “When the food system becomes less stable or less nutritious, people feel it in very real ways – in their health, their medical costs and their daily lives.”

Studies have shown that higher carbon dioxide levels can reduce iron, zinc and protein in staple crops like wheat and rice. At the same time, extreme weather events can disrupt food distribution and limit access to fresh, nutritious foods, particularly in low-income and disaster-affected communities. These shifts may worsen chronic conditions and widen existing health disparities.

Exposure to extreme heat, wildfire smoke, air pollution and climate-sensitive infectious diseases can also trigger inflammation, oxidative stress and other biological responses that affect health. Some research suggests that certain nutrients may help protect against these stressors, but more detailed knowledge is lacking.

Dietary supplements are often used to help people meet recommended nutrient intakes, and the researchers note that they could become more relevant as environmental pressures grow. They also caution that questions about safety, effectiveness, affordability and appropriate use – especially across different ages, health conditions and environmental exposures – remain largely unanswered.

Additional research is needed in three key areas: understanding nutrient gaps linked to environmental change; determining whether supplements can help the body cope with stressors such as heat, air pollution and infectious diseases; and evaluating how dietary choices and the supplement industry itself affect the environment.

The environmental footprint of dietary supplements, including how ingredients are sourced and how products are manufactured and packaged, is an issue that may matter more to consumers as awareness of sustainability grows.

“Dietary supplements are not a substitute for a healthy diet or for fixing the underlying problems in our food system,” said Jun Wu, senior author of the paper and a professor of environmental and occupational health in Wen Public Health. “But as environmental challenges intensify, it’s important to understand whether they can play a limited, evidence-based role alongside broader solutions.”

The researchers emphasize that answering these questions will require collaboration across public health, nutrition, environmental science and policy. Their goal is to inform future research and public health decisions as climate-related changes continue to influence what people eat and how those choices affect their health.