How Vitamin A, iodine and iron play a part in beating malnutrition
As incomes in developing countries rise people have moved towards eating food that is easy and fast to prepare – convenience foods. This processed food is often energy-dense and high in saturated and trans fats, sugars, salt and cholesterol.
This change in eating habits is known as a nutrition transition and it’s leading to increased health challenges, particularly in developed countries. As a result nutritionists and food system analysts across the globe are paying special attention to changes in the types and amounts of food that people consume, their exercise patterns and the affects of these lifestyles on their health.
What’s emerged is a focus on the “triple burden” of malnutrition – an energy deficiency from consuming too little food, the nutrient deficiencies from consuming food that doesn’t have essential micronutrients and an excessive net energy intake resulting in overweight and obese people.
While energy deficiency is a topic that gets most attention, and over-nutrition has also been discussed deficiencies in micronutrients are often less well understood. This is a problem because micronutrient deficiencies in vitamin A, iron, zinc, folate and iodine remain high, increasing a range of health risks. These include:
dying during childbirth;
children having an increased risk of dying from common childhood illnesses such as diarrhoea;
childhood blindness; and,
the impairment of children’s physical and cognitive development.
Sub-Saharan Africa: worst in the world
Sub-Saharan Africa has the highest prevalence of vitamin A deficiency in the world. About 48% of children between the ages of six months and five years suffer from this deficiency. Vitamin A deficiency is the leading cause of preventable childhood blindness. Vitamin A can be found in foods such as sweet potatoes, carrots and dark leafy green vegetables.
Iodine deficiency is easily preventable through the fortification of food, including salt. But in 2011 321 million people in Africa had an insufficient iodine intake, and seven of the top 10 iodine-deficient countries with the greatest numbers of school age children with insufficient iodine intake were from Africa.
In addition iron deficiency, which is the most common and widespread nutritional disorder in the world, affects a large number of children and women in developing countries. It is also significantly prevalent in the developed world. About 2 billion people – more than 30% of the world’s population – are anaemic. Many of these cases are due to iron deficiency.
In resource-poor areas, it is exacerbated by infectious diseases such as malaria, HIV/AIDS, hookworm infestation, schistosomiasis (snail fever), and other infections such as tuberculosis.
According to the World Health Organisation, in developing countries every second pregnant woman and about 40% of preschool children are estimated to be anaemic.
Anaemia contributes to 20% of all maternal deaths. Other major health consequences include poor pregnancy outcomes, impaired physical and cognitive development in children and increased risk of dying as well as reduced work productivity in adults.
Its not all bad
Some progress has been made in developed as well as developing countries.
Changes in technology, better diets and improved access to food has resulted in many benefits. This includes improved maternal and child health, the reduction of drudgery in the preparation of food, greater time for work or for leisure, and growth in both the food processing and distribution sectors.
In Africa the prevalence of under-nutrition, where people have a level of food intake that is insufficient to meet dietary energy requirements, has declined from 33% in 1990-1992 to 23% in 2014-2016.
Although food availability in sub-Saharan Africa has increased by nearly 12% over the past two decades implying that more people have more food on their plates, the total number of undernourished people continues to increase. The figure sits at an estimated 220 million.
In South Africa the situation is better than the rest of the continent. Only about 5% of the population is under-nourished. But this hasn’t improved since 1991, suggesting there is plateau that may need more than increases in food availability if under-nutrition is to be eliminated.
One way to gauge under-nutrition is to look at the rates of stunting. Children who are stunted are shorter than the expected height for their age by the time they are five. The prevalence of stunting has reduced only marginally in sub-Saharan Africa from 41% in 1990 to 35% in 2012.
There are countries on the continent that are doing well in terms of reducing under-nutrition. For example, Ethiopia reduced the prevalence of stunting from 57% in 2000 to 44% in 2011. Similarly in Ghana stunting has fallen from 35% in 2003 to 28% in 2011.
South Africa’s challenge is that although its stunting rate is lower, at 25%, the prevalence is nearly double what’s expected from a country with its economic wealth.
Solving the problems
Improving access to food is obviously key. But trends in childhood malnutrition suggest that more is needed than simply increasing the quantity of food consumed.
The challenge is that food has moved from being mostly produced on family farms and sold through fresh produce markets and small business to industrialised production, ultra-processing, mass distribution and globalised trade. This points to the need to fix flaws across the board, from how food is manufactured and distributed, to nutrition and health systems.
Addressing micronutrient deficiencies needs specific interventions. These include the fortification of food and promoting greater dietary diversity.
Julian May receives funding from the National Research Foundation for the DST-NRF Centre of Excellence