The systematic review of 13 country reports of national and sub-national programmes to fortify flour with iron found evidence for the reduction of the prevalence of low ferritin in women was more consistent than that for anaemia.
The reports from Azerbaijan, Brazil, China, Fiji, India, Iran, Kazakhstan, Mongolia, Nepal, Sri Lanka, Tajikistan, Uzbekistan and Venezuela compared data from before the programme with data from at least 12 months after it began.
Within the 13 country reports, 26 sub-groups by age and sex were described. The researchers from the Food Fortification Initiative (FFI), the industry-backed Global Alliance for Improved Nutrition (GAIN) and the US Centres for Disease Control and Prevention (CDC) found there were statistically significant decreases in the prevalence of anemia in four of 13 subgroups of children and in four of 12 subgroups of women of reproductive age.
Meanwhile there were significant decreases in the prevalence of low ferritin in one of six subgroups of children and in three of three subgroups of women of reproductive age.
The intracellular protein ferritin acts as a buffer against iron deficiency or iron overload – storing iron and releasing it in a controlled way.
Yet the paper also revealed gaps in knowledge around the impact of such fortification policies.
“More than 80 countries fortify flour, yet the public health impact of this intervention on iron and anaemia outcomes has not been reviewed,” they wrote in Nutrition Reviews.
“This review highlights the challenges of evaluating the impact of fortification when implemented on a wide scale. These challenges, along with those related to the design and execution of fortification programmes, represent opportunities to strengthen both existing fortification programmes and those yet to be implemented.”
In June a separate review of 32 countries found that in countries that fortified wheat flour alone or in combination with maize flour with at least iron, folic acid, vitamin A or vitamin B12, anemia prevalence had decreased significantly while it remained unchanged in countries that did not fortify.
Both papers raised the need for closer quality surveillance of the efficacy of fortification programmes.
They also said more research was needed on the implementation of World Health Organisation (WHO) recommendations on the type of iron used.
This latest review said there was insufficient evidence to evaluate whether programmes that followed WHO’s recommendations had better outcomes.
“The public health impact of fortification of wheat flour with iron as implemented in government programs has been incompletely documented,” the researchers wrote.
Source: Nutrition Reviews
Published online ahead of print, doi: 10.1093/nutrit/nuv037
“Evidence of the effectiveness of flour fortification programs on iron status and anemia: a systematic review”
Authors: H. Pachon, R. Spohrer, Z. Mei and M. K. Serdula