Targeting Malnutrition: Isotopic Tools for Evaluating Nutrition Worldwide
Iron Deficiency Anaemia: Finding Effective Interventions
Why is IAEA evaluating iron absorption from local foods in developing countries?
- Iron deficiency is the world's most common nutrient deficiency. Two billion people suffer from iron deficiency anaemia of which about 50% is dietary in origin. Women of childbearing age, infants, children and teenagers are especially affected.
- Iron deficiency diminishes the ability to fight infections; increases risks of premature delivery, maternal and foetal illness or death; and impairs learning and growth potential in children.
- In countries where output is based on physical labour, reduced work capacity due to poor iron status undermines economic growth.
Causes of iron deficiency
Iron deficiency results from blood loss (eg. parasitism, menstruation) or from insufficient dietary intake or absorption. Some of the best sources of iron are not affordable to the poor. However, iron from the more affordable plant based diets tends to be poorly utilized by the body.
Improving iron status
Strategies for eliminating iron deficiency (depending on its source and severity) include:
- iron fortification (adding iron to foods during the production process);
- diversification of the diet to increase iron absorption;
- iron supplementation (providing medicinal iron); and
- control of intestinal parasites (especially worms).
The flow chart depicts isotopic evaluations of iron bioavailability (absorption of iron from typical diets and fortified foods, and the influence of absorption enhancers/inhibitors) and iron status. It illustrates the important factors in deciding which intervention is most likely to alleviate iron deficiency.
Measuring iron absorption: conventional indicators and isotope techniques
The conventional indicator of mineral absorption is the chemical balance technique which measures the difference between the amount of a mineral eaten and the amount in the faeces. This method is insensitive, imprecise and time and labour consuming.
By contrast, isotope techniques:
- directly and accurately measure iron and other mineral bioavailability from single foods and total diets;
- facilitate reliable evaluations of the numerous factors that influence mineral absorption;
- make it more cost-effective to systematically study the numerous factors influencing mineral absorption; and
- help identify those food- or fortificant- based interventions most likely to succeed in target populations.
|Determining Iron Bioavailability in the Laboratory
- An alternative is to subject the food-stuff to laboratory conditions that mimic the human stomach. This measures the percentage of iron that is potentially available.
- This method is the only rapid screening tool available for comparing iron bioavalability from different foods and diets.
- It can be used to investigate different promoters and inhibitors and the effect of food processing methods on iron bioavailability.
IAEA collaborates to reduce iron deficiency
Isotopic techniques have opened the door to understanding iron absorption. The next challenge is to improve intervention programmes in relation to local foods, eating habits and hygienic conditions in developing countries.
Since the early 1990s, the IAEA has worked with donor partners, government laboratories and participating communities in improving knowledge about iron bioavailability in local meals and foodstuffs consumed in 10 Member States: Chile, Ecuador, India, Myanmar, Pakistan, Peru, Philippines, Poland, Sri Lanka, Venezuela. This information is of vital importance for:
- improving the selection and preparation of food products with high nutritional value;
- developing national nutrition strategies promoting dietary diversification and modification, food fortification and micronutrient supplementation; and
- evaluating the effectiveness of nutrition improvement programmes.
Already as a result, the Government of Venezuela began a national iron fortification programme by enriching precooked maize flour and wheat flour.