Systematic Review Yields Recommendations for Flour Fortification Programs
04 October 2015
Authors of the first systematic review of the effectiveness of flour fortification on iron and anemia outcomes offer three recommendations for improving national fortification programs. Their advice is to:
- Design or revise fortification programs so that nutrient levels used in wheat and maize flour fortification are consistent with World Health Organization (WHO) recommendations
- Monitor fortification programs for compliance and coverage
- Use biomarkers specific to the nutrients included in fortification rather than the sole use of anemia to assess fortification’s impact
The paper was published 3 October 2015 in Nutrition Reviews. It utilized in-depth reports (published and unpublished) of national and sub-national programs to fortify flour with iron. The reports were from 13 countries: Azerbaijan, Brazil, China, Fiji, India, Iran, Kazakhstan, Mongolia, Nepal, Sri Lanka, Tajikistan, Uzbekistan, and Venezuela. The reviewed reports all compared data collected before fortification with data collected at least 12 months after fortification began. Studies without a pre- and post-fortification evaluation were not included. Fortification was for wheat flour alone or in combination with maize flour.
One objective of the systematic review was to identify differences between programs that did and did not follow WHO recommendations for flour fortification. The WHO recommendations are based on the per capita intake as well as the type of flour being fortified. For example, high extraction flour, sometimes called whole grain or atta flour, requires a more bioavailable form of iron than more refined flour.
The authors found that the type of iron used was consistent with WHO recommendations in eight of the 13 studies reviewed, but only two of the studies added the minimum levels of iron.
This systematic review shows that fortification consistently improved the iron status of women, but it provides limited evidence for fortification reducing the prevalence of anemia. In contrast, a study published three months ago found that each year of fortification is associated with a 2.4% decrease in anemia. A key difference is that most of the programs analyzed in the July 2015 paper published in the British Journal of Nutrition fortified with WHO recommendations, while most programs analyzed in the Nutrition Reviews paper did not meet WHO recommendations.
“The fact that most of these programs were not aligned with WHO recommendations is understandable because they all began before the WHO recommendations were published in 2009,” noted Dr. Helena Pachón, Senior Nutrition Scientist for the Food Fortification Initiative (FFI) and lead author of the paper. “We suggest that new fortification programs should be designed to follow WHO recommendations and that existing standards be amended to follow WHO recommendations as needed.”
Co-authors of the paper are affiliated with the Global Alliance for Improved Nutrition (GAIN) and the U.S. Centers for Disease Control and Prevention (CDC) International Micronutrient Malnutrition Prevention and Control (IMMPaCt) program.
Fortification standards identify the type and amount of nutrients to be included. Monitoring the milling industry to ensure compliance with the standard is a key component to successful fortification. The systematic review found that compliance was strong in a few cases but not documented in others.
Likewise, successful programs ensure that the intended population uses the fortified food. This is called coverage. One study included in the systematic review from Azerbaijan showed that only 25% of the women reported using fortified wheat-flour products in their homes. Low coverage will limit the impact of fortification.
A health impact cannot be expected where fortification is not adequately implemented, where the fortification standard does not reflect WHO guidelines, or where coverage is low.
Another aspect of monitoring is evaluating the program’s health impact. Iron deficiency contributes to 42% of anemia among children globally and 50% of anemia among women, according to the WHO, but anemia can also be caused by factors ranging from infections to hookworms. To accurately judge fortification’s health impact, biomarkers for the specific nutrients included in the standard should be evaluated. For instance, if iron and folic acid are included in the standard, then ferritin and folate levels, respectively, should be monitored rather than using the non-nutrition-specific indicator of anemia.
The systematic review did not consider the effect of fortifying flour with folic acid to prevent neural tube defects such as spina bifida because that success is already well-documented. A meta-analysis published in the International Journal of Epidemiology in 2010 showed that fortifying flour with folic acid reduced the incidence of these birth defects by an average of 46%.
“We believe iron fortification programs can be revised to yield more positive results for the population’s iron status as well,” Pachón said.
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