Modern American supermarkets are filled with a dizzying array of products, ranging from ultra-processed to freshly picked. But even as grocery stores in remote areas are beginning to sell exotic produce from halfway around the world, an increasing amount of our calories are coming from a smaller number of crops, staples like wheat, rice, and corn.
The global food production system created by the Green Revolution of the 1960s and 70s has enabled humanity to feed more people than ever before, but at the expense of many smaller, local systems of agriculture. Keeping up with the energy needs of a booming population seemed to mean focusing ever more intensely on corn, wheat, and rice.
Humanity’s transition from nomadic hunter-gatherers to agriculturalists was one of the largest changes we’ve endured as a species. Instead of simply relying on what was available, humans began to cultivate those plants and animals that were both calorie-rich and produced reasonably dependable harvests. Nearly all the fruits and vegetables we currently eat carry the imprint of domestication. They often scarcely resemble their wild counterparts and contain smaller seeds and a greater edible portion.
Early agriculturalist civilizations grew and depended on a huge variety of foods that differed widely depending on where they lived, and this diversity persisted until the invention of the refrigerated railroad car in the 1800s and, more recently, even faster ways of moving food from Point A to Point B.
Nowadays, three crops (rice, maize, and wheat) provide 60 percent percent of the average person’s daily calories. Growing higher yields of a few staple crops has reduced world hunger, but with tradeoffs. A heavy dependence on just a few crops makes disaster more likely when harvests fail and can leave people vulnerable to nutrient deficiency and lack of sufficient food (undernutrition). At the same time, these foods provide relatively cheap, easy-to-grow forms of calories that have been linked to the recent rise in obesity around the globe. They also require more pesticides and fertilizers to grow.
“More and more, people are moving away from locally grown, locally produced foods to processed foods,” said Renaud De Plaen, a food security specialist at the International Development Research Centre in Canada. “There is this weakening of the diet, which, in many regions of the world, is resulting in a new problem. We don’t only have to tackle the problem of undernutrition, which is a major problem in developing countries, we also have to tackle obesity. It’s a double burden.”
The global food market contributes to the lack of diversity on our dinner plates. Food has always been traded, even among ancient humans, but this process first took off on a global scale after Europeans invaded the Americas. It has only grown more widespread as transportation has improved.
The global market puts small farmers in a bind, says University of Washington food economist Mary Kay Gugerty. If they want to pull themselves out of poverty, they need to sell crops, which means growing what others will buy. The market’s demand is what sets the bar for what people will ultimately grow, explains Monica Ozores-Hampton, an agricultural scientist at the University of Florida.
“From a horticultural point of view, there’s no problem growing many different types of crops, but at the same time, it’s a business. If I grow 30 different types of tomatoes and people only want five, what do I do with the rest?” she said.
Researchers like De Plaen are working to improve the variety of crops grown and sold around the world while continuing to fill an ever-growing number of hungry mouths.
One way to improve the diversity of what’s grown is to create a market for new crops. De Plaen has been working in Nigeria to promote consumption of what he calls “underutilized vegetables” like igbagba (African eggplant) through everything from ad campaigns to providing recipes and cooking tips to help people learn how to use it. Not only do these plants provide a range of micronutrients not always found in other foods, but many of them are also resilient against the effects of a changing climate, further increasing food security.
“[D]iversity is essential to food security. We need to figure out, where does it make sense to grow different types of crops so that we’re not asking people in deserts to grow foods that require lots of water,” De Plaen said.
It’s not all bad news. Travel and immigration are helping to widen food horizons. Ozores-Hampton sees this time as ripe for a renaissance for heirloom varietals and otherwise exotic produce.
“There is a higher diversity of crops than 20 years ago. If you look at the tomatoes in any regular supermarket, 20 years ago, you might have only one or two types. The other day I counted like 12 different types of tomatoes,” Ozores-Hampton said.
Growing food has always involved tradeoffs, whether it’s planting crops and risking a bad harvest or switching to new vegetables and not knowing if people will buy them. But food scientists say that, with care, we can try to reap the rewards of both worlds by continuing to invest in staple crops and promoting food diversity simultaneously.
“If you want more diversity or more small farms, you need a whole food system that’s geared towards that in terms of aggregating that produce, marketing that produce. And that’s definitely what we don’t have,” Gugerty said.