Globally, iron-deficiency anaemia is common among the poor. While appropriate supplementation or food fortification may help to prevent it, such initiatives often do not reach those who need it the most: the poorest demographics, children not attending school, men, and seniors.
Researchers at the Massachusetts Institute of Technology and India's FLAME University conducted a study to assess the impact of a potential strategy to combat iron-deficiency anaemia in rural India, using salt fortified with iron and iodine, or double-fortified salt (DFS).
They carried out a large-scale experiment in 400 villages in rural Bihar to determine the impact of selling DFS, and giving it away free of charge; at baseline, 45% of the study population was anaemic.
In 200 villages, they sold DFS for the first time, at half the regular retail price for two and a half years. In 62 of those villages, they delivered it for free to seven households for almost two years. In the other 200 villages, the study population was not made aware of DFS despite the same sales programme being implemented.
They then reported that both the sales and free experiments resulted in higher DFS consumption, especially among those who received it for free — they only stopped consuming it when they had run out of their supply.
However, among those who had to buy it, intake fell over time, with many having tried the product at least once but not continuing with it.
The researchers wrote: "This suggests that the product does not have a slow diffusion curve that would eventually culminate in large adoption."
They added that they found "no evidence that either selling DFS or providing it for free has an economically meaningful or statistically significant impact on haemoglobin, anaemia, physical health, cognition or mental health", though there was a relatively small increase in haemoglobin among adolescents.
"These disappointing results are explained both by modest purchases and low impact of DFS for the majority of the population, even when consumed somewhat regularly."
They stated that though the results were seen in only one setting and should be replicated, they did not provide positive prospects for DFS in terms of fighting anaemia in rural populations.
They concluded: "The issue with fortification may be that to make a notable difference for most people (sufficient to perhaps sustain their interest in the product), the iron dose must be large(r).
"But to be safe (and avoid poisoning due to over-consumption of iron), the concentration of iron supplementation in food must be limited. With a single source of fortified food, and a diet that continues to be low in iron, supplementation is perhaps insufficient to make enough of a difference for individuals to be willing to continue with the programme.
"This of course further reduces impact, and ultimately makes the strategy non-viable."
Source: Journal of Development Economics
"Can iron-fortified salt control anemia? Evidence from two experiments in rural Bihar"
Authors: Abhijit Banerjee, et al.