Many things have been said about the necessity for mandatory iron fortification of foods in India. That it is a ‘necessity’, ‘complementary strategy’ to dietary diversity, ‘effective’ and more loudly now, that it is ‘safe’. Given what we now know, and are uncovering, about the risks associated with too much iron, particularly in children, the proclamation of safety must be made carefully.
The simple fact is that iron is not safe in excess; it is an oxidant with a variety of ill-effects. Just because a ‘tolerable upper limit was proposed for its intake, any intake less than this was thought to be safe. But no longer. We must think of the long-term risk for other diseases, not the toxicological approach of looking at acute clinical symptoms, like stomach pain. This is because we now know that iron increases the risk for many non-communicable diseases like diabetes, hypertension and even high blood cholesterol.
What is the evidence? Take diabetes: what happens when body iron stores, measured by serum ferritin concentration, increase? In the National Health and Nutrition Examination Survey of a healthy U.S. population, those with high ferritin level had a four-fold higher risk of having diabetes. In India, our team recently analysed a national, quality-controlled survey (Comprehensive National Nutrition Survey) of Indian adolescents, to evaluate the risk of high blood sugar, high blood lipids and high blood pressure as their serum ferritin increased.
The results were scary; there was a clear and significant risk for each of these conditions as serum ferritin increased. Note that fortification of any one staple (rice, wheat, or salt) will increase serum ferritin, without necessarily changing the haemoglobin level. When provided together, the increased iron intake could be 20- 30 mg/day. We also modelled the risk when an additional 10 mg of iron/day (single staple fortification) was present: this increased high blood sugar prevalence by 2-14% across States of India, with similar findings for high blood pressure and high lipids.
Risk already high
If that is not sobering enough- another of our published analyses of the same national survey, showed that no less than 50% of Indian children, aged 5-19 years, already had a biomarker of either high blood sugar or high blood lipids, even when thin or stunted. Thus, the risk of chronic disease is already very high in our children, and we will implement this veiled threat of risk magnification by mandatory cereal fortification. Cereal intake is already too high, and should be replaced by more quality foods like pulses, fruits and vegetables, etc. We should be straining every sinew to prevent the high burden of chronic disease with life-long and intergenerational consequences, starting with our children. Remember- India is already called the world capital of diabetes and hypertension: what next?
There are also other simple truths, that should give us pause before we rush to mandatory iron fortification. First, we do not even know if anaemia is as rampant to warrant such mandatory measures. The WHO is having a consultation this year to evaluate if haemoglobin diagnostic cut-offs for anaemia should be lowered in different geographies, one of which is India. This is partly based on a recent paper in The Lancet by us, that showed that the cut-offs were likely lower than the WHO cut-off in Indian children. This lowering has been also confirmed in a study of no less than 32 countries worldwide, as well as another in pregnant women. A lower cut-off will mean a lower (halved) anemia prevalence.
Second, when mandatory fortification is enforced in parts of the population that do not need this, it removes their choice of foods, or autonomy, and could even be unethical if the risk of other morbidities is increased. Third, iron deficiency in the Indian diet is not a universal problem: the Indian requirement for iron has been lowered by half to two-thirds in 2020. Fourth, rice fortification has not been shown to work in a combined analysis, by the respectable Cochrane group, of all available and rigorous studies.
It is misleading to dismiss this analysis, and instead quote sporadic Indian studies purporting to show that fortification is successful, since these are either not published, or ‘quasi experimental’, sometimes without randomization or even a true measurement of blood haemoglobin.
Pragmatism demands that we await the forthcoming WHO haemoglobin cut-offs to get to the true anaemia burden and only rely on gold-standard venous blood haemoglobin in future surveys. Dietary modification strategies should be the preferred solutions; they are not impossible to achieve, as studies in rural India show. With the ever-expanding health care infrastructure (Ayushmaan Bharat and associated clinics), we need to move to equity for all in precision treatment: here, we should evaluate the cause of anaemia and prescribe treatment accordingly. Experience from Covid testing shows that India can do it!
( Anura Kurpad is Professor of Physiology and Nutrition in St John’s Medical College, Bengaluru, and Harshpal Singh Sachdev is a senior consultant in Paediatrics and Clinical Epidemiology, Sitaram Bhartia Institute of Science and Research, New Delhi )