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Global Diets Growing Similar

FILE - An Afghan refugee collects a bag of wheat being distributed by the World Food Program and USAID at Jalozai refugee camp near Peshawar, Pakistan.

FILE - An Afghan refugee collects a bag of wheat being distributed by the World Food Program and USAID at Jalozai refugee camp near Peshawar, Pakistan.

Around the world, our plates are looking more and more the same, according to a new study.

Several crops have risen to dominate global food supplies. That’s good news and bad, the study says.

National food supplies have become less dependent on a single crop. But today’s globalized diet centers around just a handful of crops, which the researchers say raises food security concerns.

And, the study notes, some of the world-conquering crops are key ingredients in unhealthy diets.

More wheat

The research in the Proceedings of the National Academy of Sciences, analyzed national per-capita food supply data collected by the U.N. Food and Agriculture Organization since 1961.

It found the number of crops making up a significant part of people’s diets has increased in most countries in the last half-century.

In China, for example, rice is still the top crop, making up about one third of the average person’s calories from plants per day. But the Chinese now eat almost as much wheat as rice.

Fewer sweet potatoes

On the other hand, what used to be minor crops are now slipping further.

The consumption of sweet potatoes in China fell from 20 percent of daily calories in 1961 to 2.9 percent in 2009, the latest available data.

In Kenya, more than a third of daily calories come from corn, but that is down from nearly half in 1961. Meanwhile, wheat has grown from less than 3 percent to more than 10 percent.

“As the major crops become more important in more places for more people, the regionally important, locally important crops are becoming marginalized,” according to lead author Colin Khoury at the International Center for Tropical Agriculture.

Khoury says as a few crops become the basis of our diets, “those crops need to be resilient, need to be productive year after year after year."

That means preserving genetic diversity to safeguard against new threats to productivity from climate change or other factors. And, Khoury said, it means improving the nutritional content of the crops that make up a growing part of our diet.

Marginalized crops

Climate change and the environmental risks of current agricultural practices make some of the marginalized crops more attractive, the researchers said.

“These crops have a lot of potential,” said Danielle Nierenberg, head of the Washington-based research institute Food Tank, who was not involved in the research. “They’re often highly nutritious. They can grow in very harsh conditions. Most are very resilient to things like pests and disease and drought or flooding, and they’re easy to grow.”

But these crops are left out when it comes to research and development, she says, as the vast majority of funding goes toward the starchy staple crops.

The study also noted that sugar and oil crops such as soybean, palm and sunflower have seen substantial growth in the last 50 years. But increasing consumption of high-calorie foods made with these crops is associated with diabetes, heart disease and cancer.

The researchers found signs of a shift in response to health, environmental and climate concerns, beginning in Northern Europe. And, they concluded further diversifying the food supply could encourage the trend.
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    Steve Baragona

    Steve Baragona is an award-winning multimedia journalist covering science, environment and health.

    He spent eight years in molecular biology and infectious disease research before deciding that writing about science was more fun than doing it. He graduated from the University of North Carolina at Chapel Hill with a master’s degree in journalism in 2002.