Carbon Dioxide May Rob Crops Of Nutrition, Leaving Millions At Risk

http://www.npr.org/sections/thesalt/2017/08/02/540650904/carbon-dioxide-may-rob-crops-of-nutrition-leaving-millions-at-risk

August 2, 20172:30 PM ET
Courtney Columbus

Rising carbon dioxide levels could have an unexpected side effect on food crops: a decrease in key nutrients. And this could put more people at risk of malnutrition.

A 2014 study showed that higher levels of carbon dioxide in the atmosphere are likely to put a dent in the protein, iron and zinc content of rice, wheat, peas and other food crops. Samuel Myers, an environmental health researcher at Harvard's School of Public Health, was the lead author on that study.

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One study published in Environmental Health Perspectives estimates that the predicted decreases in the protein content of food crops may put about 150 million additional people at risk of protein deficiency by 2050. The other study, published online in GeoHealth, found that the available dietary iron supply could decrease in some high-risk regions.

Wheat and rice are not high in protein, but nearly three-quarters of the world's population uses these two crops as "primary protein sources," the study says, based on data from the U.N. Food and Agriculture Organization.

And so, any reduction in protein contained in these crops can lead to health problems, particularly for poorer people in low income countries, says Myers.

Eighteen countries in Asia and Africa – including India, Bangladesh, Turkey, Egypt, Iran and Iraq — may lose more than 5 percent of their dietary protein, the authors find. For about 150 million people in these countries, that loss is enough to make them protein deficient.

Protein deficiency is known to lead to low birth weight, stunting and other growth issues that influence overall health and well being.

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The study on iron deficiency found that 354 million children aged 1 to 5 and about 1 billion women of child bearing age live in countries where the amount of dietary iron is projected to fall by more than 3.8 percent. These countries already have a high prevalence of anemia.

Iron deficiency is the most common cause for anemia. And a "staggering" number of people are anemic – two billion, according to the World Health Organization. Iron deficiency can also impair growth and lower children's IQs.

According to the new study, south and southeast Asia, sub-Saharan and northern Africa and the Middle East are at highest-risk of experiencing a further rise in number of people with iron deficiency. These areas are economically poorer, and people there get most of their iron from plants.

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