According to research recently published in the Journal of Nutrition, potatoes can also be an excellent source of iron, and not just a good source of energy, potassium and vitamins C and B6, as previously thought. This means potatoes could play an important role in efforts to reduce iron deficiency – the leading cause of anemia, which affects about two billion people globally.

In developing countries, about half of pregnant women and 40% of preschool children suffer from anemia, which impairs children’s physical and mental development, makes adults less productive, and contributes to about 20% of maternal deaths.

A study with iron-deficient women in Peru’s Huancavelica region, who ate 500 grams of potatoes per day for two weeks, found that the rate of iron absorption from those potatoes was much higher than that reported for other crops. Whereas people absorb only about 2-10% of the iron in most vegetables, 8% of the iron in pearl millet and less than 10% of the iron in beans, participants in this study absorbed 28% of the iron in the yellow-fleshed potato they ate. The 500 grams of that potato participants consumed thus provided 33% of the daily iron requirement of a woman of reproductive age.

“Nobody expected the potato to have such a high level of iron absorption,” said Gabriela Burgos, a nutritionist at the International Potato Center (CIP), which undertook the study in collaboration with ETH Zürich and Peru’s Instituto de Investigación Nutricional. She added that this was the first human study of iron bioavailability in potato ever done, and that it produced the kind of pleasant surprise that scientists hope for.

“Potato has great potential for reducing iron-deficiency, even though it contains much less iron than crops such as beans or spinach, because a higher proportion of the potato’s iron is absorbed by the human body,” said Burgos, one of the study’s leading authors.

She explained that this is because most vegetables and other produce contain high levels of phytates and other compounds that inhibit iron absorption, whereas potatoes have low phytate levels and plenty of vitamin C, which enhances iron absorption.

The study’s results are especially significant because they took place in the framework of an initiative to increase the iron levels of potato through conventional breeding – a process called biofortification. The resulting varieties will be disseminated in areas where iron deficiency is a problem.

According to Burgos, biofortified potatoes are an excellent option for reducing iron deficiency in highland areas like Huancavelica, where people eat meat infrequently and most adults consume 300—600 grams of potato per day. They could be equally beneficial in potato producing areas of Africa and Asia, where people have comparable diets.