Fortifying corn flour can reduce birth defects

By Karen Mancl and Zhiyuan Zhou, Ohio State University

While studying the ingredient labels on foods as I planned for guests coming to summer cookouts and tailgates, I noticed that all the buns, crackers, and pasta contain folate or folic acid. In 1998, the U.S. Food and Drug Administration (FDA) required wheat and rice products to be fortified with folate, a B vitamin, to prevent birth defects. Medical research confirmed in the 1980s that a folic acid deficiency during pregnancy could result in Spina bifida, a Neural Tube Disorder (NTD) where the spine does not fully close. The fortification of bread, cereal, pasta, and rice has resulted in a 28% drop in Spina bifida cases in the United States.

However, the federal requirement did not extend to corn-based products such as corn flour and masa used to make tortillas. In Latin American households where corn is a staple food, studies show the incidence of this birth defect is double that for white and black women. To change that, starting in 2026, California now requires fortification of corn flour and masa. An Alabama law requiring corn fortification takes effect in June 2026, and four other states are considering similar laws.

Confirming the folic acid deficiency – birth defect link

Since the mid-1960s, American scientists have suspected that folate deficiency might lead to birth defects, but the mechanisms were unclear. It was difficult for U.S. researchers to find enough cases to study and confirm their suspicions. It was a chance meeting in 1983 between two doctors, Dr. Oakley from the U.S. Centers for Disease Control (CDC) and Dr. Yan from the Beijing Medical University (BMU), at a medical conference in Beijing that led to a breakthrough.

In China in the early 1980s, with its population of more than 1 billion people, about 100,000 infants were born each year with Spina bifida. At the conference, the two doctors decided to collaborate and greatly expand their case numbers to consider a link between folate deficiency and birth defects. More than 250,000 Chinese women participated in this joint study. The U.S.-China Science and Technology Agreement, signed in 1979, opened the door to collaboration between the two countries. Their international work did face political challenges, ideological differences, and funding difficulties. But by combining their efforts and greatly expanding the number of cases, the collaboration quickly confirmed the link between a vitamin deficiency and a birth defect.

The future of United States and China collaboration

It was the 1979 U.S.-China Science and Technology Agreement that set the framework for government agencies, universities, organizations, institutions, and others to have contact and cooperate. Through the agreement, the United States and China have been able to share important information while protecting intellectual property in agriculture, space exploration, and medicine. With each reauthorization of the agreement, the topics for collaboration have expanded to include energy and the environment. More protections have been included in the agreement to reduce risks as China’s technological capacity has expanded. The agreement was once again renewed in 2024.

With the concrete conclusions from the CDC-BMU project, the United States and China amended their public health policies. In 1998, the U.S. Food and Drug Administration required folic acid to be added to grain products, such as bread, pasta, rice, and cereal. Since then, Spina bifida and other NTDs in the United States dropped 28%. It will drop even more as folic acid is now being added to corn products. In a 1998 speech at the Beijing Medical University, the then U.S. First Lady Hillary Clinton commended the CDC-BMU project on Spina bifida as the greatest example of U.S.-China collaboration. “Our grandchildren,” she said, “will have to look in history books, not medical books, to learn about diseases like Spina bifida.”

Karen Mancl, Ph.D., is Professor Emerita of Food, Agricultural & Biological Engineering at The Ohio State University. Zhiyuan Zhou was a research assistant at the Wilson Center for International Scholars. To learn more about Chinese and U.S. agriculture and environment, go to the website for the Soil Environment Technology Learning Lab at SETLL.osu.edu.