A new study published in The Journal of Nutrition has found that daily consumption of meals with beans conventionally bred to be richer in iron help prevent and reverse iron deficiency in young Rwandan women in just four-and-a-half months.  

Iron deficiency is one of the commonest micronutrient deficiencies in the world, impacting women, children, and infants most severely. Lack of iron can impair cognitive and physical development. Severe anemia, often caused by iron deficiency, increases risks to women during childbirth, and can cause death. Despite efforts to curb iron deficiency through supplements and fortified foods, iron deficiency remains the most widespread nutrition deficiency, affecting an estimated 1.6 billion people worldwide.

For this study, 239 iron-deficient Rwandan women between the ages of 18 and 27 participated in a double-blind randomized efficacy trial. One group ate iron beans while the control group ate the local common variety. Both groups ate between 150-175 grams (wet weight) of cooked beans for lunch and dinner for 18 weeks. Each meal consisted of beans, two sides (usually potatoes, rice, or cassava), a green leafy vegetable, and a tomato-based sauce. No meat was served during the trial. The study found that the estimated body iron increase was 0.50 milligrams per kilogram higher than in the control group.

“In this study we see a significant reduction in iron deficiency and also an increase in hemoglobin levels of women who ate iron beans,” said Jere Haas, lead scientist on the study. “All consumers have to do is to replace the common variety of beans with more nutritious biofortified varieties.”

This is the first time that the effect of iron beans on anemia and iron deficiency has been shown in published research. It adds to a growing literature on the efficacy of biofortified crops. An earlier study in India showed that pearl millet bred to be richer in iron was able to reverse iron deficiency in school-aged children within six months. Another efficacy study in the Philippines showed modest improvement in iron levels of women who ate iron-rich rice.

HarvestPlus, a global program to improve nutrition and public health, is promoting iron beans—and other biofortified staple crops—in several countries. More than a million farming households in Africa and Latin America have adopted these more nutritious beans, which also boast other desired agronomic traits.

“These beans are not just great for consumers, they are also great for farmers,” said Steve Beebe, leader of the Bean Program at the International Center for Tropical Agriculture (CIAT), a partner in the research. “As well as producing good yields, they can also tolerate intermittent drought, making them very attractive for bean producers in many parts of the tropics.”

With 2016 designated as the International Year of Pulses, the study’s findings further underline the significance of beans for nutrition.

“To take a wider view, this study confirms the value of beans as an important ingredient of health-promoting diets,” said Erick Boy, Head of Nutrition at HarvestPlus. “We knew that beans are rich in fiber, which is beneficial for its effects on cholesterol and colon cancer; they also improve the quality of the protein of meals based solely on other starch staples like maize, rice or cassava. The study clearly shows that biofortified beans also help prevent and reverse iron deficiency in young women before pregnancy – the future mothers of generations to come.”

Journal Article 
Consuming Iron Biofortified Beans Increases Iron Status in Rwandan Women after 128 Days in a Randomized Controlled Feeding Trial