"Tortillas di una miscela di mais azzurro tostato" by fugzu is licensed under CC BY 2.0

Neural Tube Defects Are Preventable: Buy Corn Masa Flour and Tortilla Products That Contain Folic Acid

MedicalResearch.com Interview with:
"Tortillas di una miscela di mais azzurro tostato" by fugzu is licensed under CC BY 2.0Vijaya Kancherla, PhD

Research Assistant Professor, Department of Epidemiology
Epidemiologist, Center for Spina Bifida Prevention
Rollins School of Public Health
Emory University
Atlanta GA 30322

MedicalResearch.com: What is the background for this study?

 Response: The scientific evidence since 1991 has shown that folic acid prevents from 35%-95% of neural tube birth defects that are caused due to low folic acid (also known as vitamin B9) in the mother’s diet prior to conception and during early pregnancy. Neural tube defects form in the embryo at 4th week of gestation when most women are unaware they are pregnant.

Taking any amount of folic acid after the 4th week of pregnancy will not prevent neural tube defects. There is no cure for these birth defects. So, it matters for women to have enough folic acid prior to conception and in the first four weeks of pregnancy. If a woman is not taking prenatal vitamins that early, folic acid fortified foods come to rescue. Foods fortified with folic acid will prevent folate deficiency for everyone, and offer the benefit to mothers who were not planning their pregnancies or were not taking folic acid pills. If corn masa flour and tortillas were fortified with folic acid, that would help millions of reproductive aged women have healthy stores of folic acid in their bodies, to prepare them for their pregnancy, irrespective of their pregnancy plans.

Prior to April 2016, folic acid (also known as vitamin B9) was not allowed to be added to corn masa flour (or products made from masa such as tortillas and tortilla chips) in the US. So, there was no expectation of having folic acid in these products.

The March of Dimes, Spina Bifida Foundation, the American Academy of Pediatricians, Gruma Corporation and others filed a petition with the US FDA and succeeded in allowing millers to voluntarily add folic acid to corn masa flour and tortillas as a food additive. This regulation was implemented by the US FDA in April 2016. 

MedicalResearch.com: What are the main findings?

Response: Twenty months after the legislation permitting folic acid in corn masa flour and tortillas was passed, our study showed that nearly all the masa flour and all soft tortillas in northeast Atlanta still did not contain folic acid. To our knowledge, this is the first study of its kind to evaluate whether the voluntary policy has resulted in corn masa fortification. If what we found in the Atlanta market is true nationwide, and we think it is because we tested national brands, this means folic acid is not reaching the intended population – that being many Hispanic people who consume foods made with corn masa flour. This is needed to reduce the two-fold increase in occurrence of neural tube defects, such as anencephaly and spina bifida, in babies born to Hispanic mothers compared to other race/ethnic groups in the US.

Fortification of corn masa flour and tortillas is an especially important public health intervention to close the gap in the prevention of neural tube defects in the US. The 1996 FDA decision to require folic acid to be included in enriched cereal grain products, like enriched wheat flour, has benefitted thousands of families by preventing folic acid-preventable neural tube defects. We were hoping for the same benefit for the Hispanic population. 

What is new and surprising is that the voluntary corn masa fortification policy that was introduced in April 2016 is not working, at least not in markets of northeast Atlanta that cater to a large population of Hispanic residents. Our main finding is that only 2 of the 41 products we examined contained folic acid, though we were expecting all of them to have folic acid 20 months after the FDA allowed folic acid as an additive. This voluntary approach is not working as millers are not mandated to add folic acid to corn masa and tortilla products. We have to explore other methods, such as mandatory fortification, to make this intervention successful.

We know the number of Hispanics in the US is increasing. There are over 10 million Hispanic women of reproductive age in the US. Both fertility and birth rates are higher for Hispanics than their counterparts in the US. For many reproductive-aged Hispanic women in the US (especially those of Mexican American and Central American origins), the staple food is corn masa. By not fortifying this food vehicle, the intervention to prevent neural tube defects fails. This is a vulnerable population. Recent data shows that Hispanic mothers are two times more likely to have a baby with a neural tube defect compared to non-Hispanic whites in the US. The other race/ethnic groups whose staple foods consist of enriched cereal grains have seen a significant reduction in the prevalence of neural tube defects after the 1996 mandatory policy of cereal grain fortification in the US. But the same has not been observed for Hispanic populations. That clearly indicates mandatory fortification failed in a sub-group of US population whose diet differs from the rest of the country. We also know that Mexican American women have lower average total folic acid intake in diet and as supplement pills, and lower average blood levels of folates, compared to non-Hispanic white women. Folate is what vitamin B9 is called when it is in the natural form, as found in unfortified foods. We can measure folate levels in the blood. Hispanics would benefit from folic acid fortified corn masa in multiple ways (e.g., preventing folate deficiency anemia, preventing folic acid-preventable neural tube defects).

Our study adds to the understanding about the effectiveness of recent policy allowing voluntary fortification of corn masa and corn tortillas in the US looking at national brands available in the market. This is a major gap in prevention. It is also an inequity in public health and a missed opportunity. Corn masa millers can fix this issue by fortifying corn masa products. 

MedicalResearch.com: What should readers take away from your report?

"Day 77 - Tortillas" by Cristiano Betta is licensed under CC BY 2.0Response: The take home message for readers is simple: Only buy corn masa flour and tortilla products that contain folic acid. To do this, look at the nutrition label on corn masa products and buy only those brands that have folic acid on their labels. At the same time, women should take prenatal vitamin pills containing at least 400 micrograms of folic acid daily, whether or not they are planning pregnancy. Taking prenatal vitamins after the pregnancy test comes out positive is too late to prevent neural tube defects. One has to have folic acid before pregnancy and in the first four weeks of pregnancy for preventing neural tube defects. Timely folic acid intake will improve folate levels in the body and prepare them for a healthy pregnancy when they are ready to have a baby, or if an unintentional pregnancy occurs. This is the most effective primary prevention for neural tube defects as there is no cure for it once the defect occurs.

Without a specific blood test it is hard for an individual to know what their folic acid status is. However, people who eat enriched grains generally get plenty of folic acid from their regular diet. We need enriched corn masa flour so that Hispanic women with lower acculturation, whose staple is corn masa, would rather easily get needed folic acid from their regular diet. 

We want to stress that although folates are naturally available in certain foods such as leafy greens, vegetables, beans, etc., they are not easily absorbed by the body, and their levels are depleted from the cooking process. Also, these dietary sources would have to be consumed in unrealistically large quantities to meet our daily requirement. Thus, it is very hard to get enough vitamin B9 from unfortified foods alone to prevent birth defects. This is why adding folic acid to corn masa flour is needed. It is cheap, safe, and cost-effective. More than 60 countries fortify staples foods with folic acid and have noted significant reductions in their prevalence rates of neural tube birth defects. Closing this prevention gap for millions of Hispanics in the US can only occur if the millers partner on this public health issue, and fortify corn masa flour and tortillas. The fortification will be much more effective if it is mandated, so no miller can opt out of fortification and gain financially from it.

MedicalResearch.com: What recommendations do you have for future research as a result of this work?

Response: Other markets in the US should also be studied to make sure all brands of corn masa flour and tortillas are tested. Out study tested some major national brands of corn masa products, but we need data from other cities to increase representativeness of our findings. There need to be increased awareness among Hispanic women of reproductive age to choose brands that have folic acid in them, and at the same time take 400 mcg/day of folic acid every day to improve their folate levels. We need better public health education campaigns on conveying these messages to the target populations who will most benefit from this research, including the corn masa millers.

MedicalResearch.com: Is there anything else you would like to add?

Response: Acculturation of Hispanics plays in important role in this issue. Hispanic women, especially those who have lower acculturation (e.g., reported primarily speaking Spanish, living in the United States for <15 years, or being born in Mexico), do not follow typical US diets, and thus will not receive folic acid from other enriched cereal grains and breakfast cereals. If they did, their dietary and blood folate levels would be relatively high, or even similar to that of non-Hispanic women of reproductive age. But we have not seen this in any of the nutritional surveys. Analyses based on a large national nutritional survey study in the US consistently show that Hispanic women of reproductive age have diets with low dietary folate. From these same national nutritional surveys, we found that Mexican American women have lower average total folic acid intake in diet and as supplement pills, and lower average blood levels of folates, compared to non-Hispanic white women. Lastly, Hispanics who spoke Spanish at home were almost two times more likely to have a baby born with spina bifida than non-Hispanic white women. A similar difference was not observed between English-speaking Hispanic women and non-Hispanic white women.

A large number of Hispanics are not acculturated, and their numbers will be increasing. Their primary staple is corn masa and its products. If we do not bridge this gap in prevention of neural tube defects in this sub-population, the consequences can be dire for families who will have babies with a preventable neural tube birth defect. The costs associated with life-long care of these babies will be felt both by the families and the health care system. Many children with spina bifida can lead productive lives, but their care takes a toll on the entire family psychologically and financially.

Senior Author (and Subject Matter Expert):

Dr. Godfrey P. Oakley Jr. Director, Center for Spina Bifida Prevention

Research Professor, Department of Epidemiology

Emory University Rollins School of Public Health, Atlanta, GA.

None of the authors have any financial ties to companies in this regard.


For questions or interview requests, please contact:

Dr. Oakley Jr. [email protected] / Phone: 678 613 6918

Dr. Kancherla [email protected] / Phone: 404 727 8884 


Redpath B, Kancherla V, Oakley GP. Availability of Corn Masa Flour and Tortillas Fortified With Folic Acid in Atlanta After National Regulations Allowing Voluntary Fortification. JAMA. 2018;320(15):1600–1601. doi:10.1001/jama.2018.11939

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Last Updated on October 19, 2018 by Marie Benz MD FAAD