Quantcast

High CO2 Levels Make Rice Less Nutritious, Study Finds

Climate
Terraced rice field in Yabu-shi, Hyogo Prefecture, Japan. cotaro70s / CC BY-ND 2.0

Research published Wednesday in Science Advances found that rice grown with the higher atmospheric carbon dioxide concentrations expected by the end of this century was less nutritious, signaling bad news for the more than two billion people who rely on the grain as their primary food source, a University of Washington (UW) press release published in EurekAlert! Reported.


"Rice has been a dietary staple for thousands of years for many populations in Asia and is the fastest growing food staple in Africa," study co-author and Director of the UW Center for Health & the Global Environment Kristie Ebi said in the release. "Reductions in the nutritional quality of rice could affect maternal and child health for millions of people."

The team of researchers from China, Japan, Australia and the U.S. conducted a field study in China and Japan of 18 strains of rice. They confirmed previous studies showing that the higher levels of carbon dioxide expected by 2100 decreased the amount of zinc, protein and iron found in rice. They also discovered for the first time that the higher carbon dioxide levels also decreased the amount of B1, B2, B5 and B9 vitamins, which are important for helping people get the most energy from their food.

Overall, average B1 levels decreased by 17.1 percent, average B2 levels by 16.6 percent, average B5 levels by 12.7 percent, average B9 levels by 30.3 percent, average iron levels by 8 percent, average zinc levels by 5.1 percent and average protein levels by 10.3 percent.

Researchers said that the lowered nutritional content of rice is most likely to impact the 600 million people, mostly in Southeast Asian countries, who rely on rice for more than 50 percent of their energy and protein intake. The region is already projected to be especially vulnerable to climate risks such as extreme weather and sea level rise. A 2018 ranking by HSBC of the nations most vulnerable to climate change found that half of the top ten were in South or Southeast Asia, The World Economic Forum reported. This study adds another worry.

"This is an underappreciated risk of burning of fossil fuels and deforestation," Ebi said.

Rice nutrition will also have a greater impact on people living in countries with lower Gross Domestic Products (GDPs), since people tend to diversify their diet as their country's GDP improves. Lowered nutrition could increase the risk of malaria, stunting and diarrhea in impacted populations, the study found.

The study complicates the idea that carbon dioxide will increase plant growth. "People say more CO2 is plant food—and it is. But how plants respond to that sudden increase in food will impact human health as well, from nutritional deficits, to ethno-pharmacology, to seasonal pollen allergies—in ways that we don't yet understand," study co-author and U.S. Department of Agriculture researcher Lewis Ziska said in the release.

He further told The Guardian that more research was needed to assess the impact of increased carbon dioxide levels on the nutritional content of other crops.

"Many important cereals like wheat as well as staples like potatoes may be impacted by this as well," he said.

The researchers said it might be possible to select for strains of rice that resisted the nutritional effects of increased carbon dioxide, but that this would take time. Another possibility would be to nutritionally enrich the rice with special fertilizers or enhancements after harvest and to educate impacted populations of the need to supplement their diets as carbon dioxide levels rise.

EcoWatch Daily Newsletter

A timelapse video shows synthetic material and baby fish collected from a plankton sample from a surface slick taken off Hawaii island. Honolulu Star-Advertiser / YouTube screenshot

A team of researchers led by the National Oceanic and Atmospheric Administration didn't intend to study plastic pollution when they towed a tiny mesh net through the waters off Hawaii's West Coast. Instead, they wanted to learn more about the habits of larval fish.

Read More Show Less
Two silver-backed chevrotain caught on camera trap. The species has only recently been rediscovered after being last seen in 1990. GWC / Mongabay

By Jeremy Hance

VIETNAM, July 2019 – I'm chasing a ghost, I think not for the first time, as night falls and I gather up my gear in a hotel in a village in southern Vietnam. I pack my camera, a bottle of water, and a poncho; outside the window I can see a light rain.

Read More Show Less
Sponsored
Flooding in New Orleans from Hurricane Katrina on Sept. 11, 2005. NOAA Photo Library / Lieut. Commander Mark Moran

The most destructive hurricanes are three times more frequent than they were a century ago, new research has found, and this can be "unequivocally" linked to the climate crisis.

Read More Show Less

By George Citroner

The Office of Disease Prevention and Health Promotion and the World Health Organization currently recommend either 150 minutes of moderate intensity exercise (walking, gardening, doing household chores) or 75 minutes of vigorous aerobic exercise (running, cycling, swimming) every week.

But there's little research looking at the benefits, if any, of exercising less than the 75 minute minimum.

Read More Show Less
Mary Daly, president of the San Francisco Federal Reserve Bank, poses for a photograph. Nick Otto / Washington Post / Getty Images

It seems the reality of the climate crisis is too much for the Federal Reserve to ignore anymore.

Read More Show Less
Sponsored

Passengers trying to reach Berlin's Tegel Airport on Sunday were hit with delays after police blocked roads and enacted tighter security controls in response to a climate protest.

Read More Show Less
A military police officer in Charlotte, North Carolina, pets Rosco, a post-traumatic stress disorder companion animal certified to accompany him, on Jan. 11, 2014. North Carolina National Guard

For 21 years, Doug Distaso served his country in the United States Air Force.

He commanded joint aviation, maintenance, and support personnel globally and served as a primary legislative affairs lead for two U.S. Special Operations Command leaders.

But after an Air Force plane accident left him with a traumatic brain injury, post-traumatic stress disorder (PTSD), and chronic pain, Distaso was placed on more than a dozen prescription medications by doctors at the U.S. Department of Veterans Affairs (VA).

Read More Show Less
(L) Selma Three Stone Engagement Ring. (R) The Greener Diamond Farm Project. MiaDonna

By Bailey Hopp

If you had to choose a diamond for your engagement ring from below or above the ground, which would you pick … and why would you pick it? This is the main question consumers are facing when picking out their diamond engagement ring today. With a dramatic increase in demand for conflict-free lab-grown diamonds, the diamond industry is shifting right before our eyes.

Read More Show Less