Studies across the world have revealed substantial declines in the range of traditional vegetable varieties grown over the past century, while almost one-quarter of assessed wild relatives of major vegetable crops are going into extinction.

This was contained in a study published in the Proceedings of the National Academy of Sciences (PNAS), where the researchers highlighted spider plant in Africa, bitter gourd in Asia and slippery cabbage in the Pacific as examples of overlooked vegetable crops that could help improve diets and strengthen agriculture against climate change.

An international team of scientists is calling for a global effort to rescue, conserve and make better use of vegetable biodiversity, warning that modern food systems are becoming increasingly dependent on a small number of widely grown vegetable crops.

The researchers use the term vegetable biodiversity to describe the full range of vegetable species, traditional varieties and their wild relatives. The findings come as people worldwide consume nearly 40 per cent fewer vegetables than recommended by the World Health Organisation (WHO), as global production remains insufficient to meet recommended intake, and low vegetable consumption is among the five leading dietary risk factors contributing to the global burden of disease.

The United Nations recently warned that more than one in three people cannot afford a healthy diet, highlighting the need to make foods such as vegetables more affordable and accessible.
 
The researchers argue that simply producing more of today’s most common vegetables will not be enough. They claimed that many traditional and underused vegetables are rich in vitamins and minerals, well adapted to local growing conditions and valued in local food cultures. Their diverse varieties and wild relatives also contain characteristics that can be used to develop vegetables better able to withstand heat, drought, pests and diseases.
 
The Lead Researcher, Dr. Maarten van Zonneveld, said the solution isn’t simply to grow more vegetables – it’s also to grow more kinds of vegetables. “Much of the vegetable biodiversity we need is still out there – in traditional varieties and their wild relatives. The urgency is to conserve it properly so that we can use it wisely to diversify diets amid climate change,” he said.

The researchers identify more than 1,480 edible vegetable species worldwide, though they say the true number is likely to be even higher. Many are poorly researched and underused despite their importance in local diets and farming systems.

The study also highlighted vegetables such as spider plant in Africa, bitter gourd in Asia, slippery cabbage in the Pacific, and the edible leaves of pumpkin, sweet potato and cowpeas.

Many are naturally rich in vitamins and minerals, adapted to challenging growing conditions and valued in local food cultures, yet they receive only a tiny fraction of the research, breeding and conservation efforts devoted to globally traded vegetables and staple grains.

By showing, which vegetables are most relevant to different regions and climate challenges, the report said the list would help researchers, practitioners and policymakers identify priorities for conservation, breeding and wider use. But the researchers warn that many of these resources are already disappearing.

According to the Global Conservation Lead at the Crop Trust, Dr. Colin Khoury, vegetable biodiversity is one of the world’s greatest assets for improving diets and adapting agriculture to a changing climate, “but we’re losing it at exactly the time we need it most. Conserving vegetable biodiversity isn’t just about protecting the past – it’s about securing more options for the future.”

The researchers argue that conserving vegetable biodiversity is not enough on its own. They noted that protecting seeds in genebanks helps safeguard them against permanent loss, but sustainably improving nutrition also depends on ensuring vegetables – traditional and otherwise – continue to be improved by plant breeders, grown by farmers, sold in markets and eaten by consumers. As a result, they argue that the conservation and use of traditional and wild vegetables must go hand in hand.

They outlined four priorities for governments, funders, and researchers: secure vegetable biodiversity for the future by rescuing, conserving and restoring traditional vegetable varieties and their wild relatives; use vegetable biodiversity to develop improved varieties by expanding research, breeding and access to diverse genetic resources; promote vegetable biodiversity to diversify diets by increasing the production, availability and consumption of a wider range of vegetables; and embed vegetable biodiversity in policy by integrating it into agriculture, health, education, climate and biodiversity strategies.

The researchers said taken together, the priorities would shift vegetable biodiversity from being an overlooked resource to a central part of efforts to improve diets, strengthen climate resilience and develop the vegetables needed now and into the future. They noted that the findings align closely with emerging international efforts such as Vegetables4Life, a global initiative led by WorldVeg and co-led by the Global Crop Diversity Trust to rescue, conserve and use vegetable diversity in biodiversity and malnutrition hotspots worldwide.

The research brought together experts from the World Vegetable Centre, the Crop Trust, the International Potato Center (CIP), Centre for Pacific Crops and Trees (Pacific Community), Wageningen University & Research, the International Centre for Tropical Agriculture (CIAT), the Food Security Leadership Council, New York Botanical Garden, and the CGIAR Genebank Accelerator.