Micronutrients must have Bioefficacy

In their SciDev.Net article, Thorne-Lyman and Fawzi highlight the links between malnutrition and infectious disease. I agree with their assessment that micronutrient interventions offer a low-cost, yet underfunded, strategy for preventing and treating infectious disease, and that it is ‘time to turn knowledge into action’.

The underlying problem is that people have moved away from their traditional diets, while a combination of environmental degradation, modern agricultural practices and food processing removes essential nutrients from our food. The malnourished are being fed refined foods, fortified with vitamins and minerals in the form of chemical isolates.

In southern Africa, a traditional nutrient-rich diet would include home-grown millet and sorghum, hand-gathered herbs, roots and fruits, as well as groundnuts, sweet potato, pumpkin, cabbage and a moderate intake of free range meat, eggs and milk. The staples today are refined maize meal, bread (mostly refined) and white sugar – all of which provide ’empty calories’ – together with cooking oil and traditional margarine packed with extremely unhealthy trans-fats.

The consequences for nutrition are severe. In Mozambique, 95 per cent of children under five suffer from iron deficiency. A National Food Consumption Survey in 1999 found that South African children were deficient in iron, zinc, vitamin A and most of the B vitamins. Is it any wonder that immunity is impaired and there is an escalating prevalence of infectious disease?

To address micronutrient deficiencies, especially in the most vulnerable, South Africa began a food fortification programme in 2004, adding iron, zinc, vitamin A, B vitamins and folic acid to all maize and wheat flour. But, five years on, the project was judged a resounding failure. Apart from a modest improvement in folic acid status, the prevalence of vitamin A, zinc and iron deficiencies in children had all increased.

Hurrell evaluated wheat flour iron fortification programs in 78 countries, and concluded that most are likely to be ineffective. He argues that legislation needs updating in many countries so that flour is fortified with adequate levels of the recommended iron compounds. This ignores that fact that most legislation in this area has been framed on the advice of international agencies, and in their latest advice, the WHO states, ‘The selection of the type and quantity of vitamins and minerals to add to flour, either as a voluntary standard or a mandatory requirement, lies with national decision makers in each country and therefore the choice of compounds – as well as quantities – should be viewed in the context of each country’s situation’. This is not helpful.

Part of the problem in South Africa is that fortification is based on adult food portions. Children, who are more vulnerable, eat less and so need more highly fortified food. Another problem is that cooking can destroy the vitamins. But, most importantly, it is because chemical isolates have a significantly lower bioefficacy than whole foods. Fortifying or supplementing a defective diet with micronutrients in the form of chemical isolates is now commonplace, despite a plethora of scientific evidence that they are poorly absorbed, rarely act in the body in the way intended and, in some cases, may even be toxic.

Take, for example, the essential mineral and antioxidant, selenium. Where there is deficiency, bread or salt is often fortified with sodium selenate or selenite. But this is unlikely to have the desired benefit because these salts are toxic and poorly absorbed – and the little that is absorbed does not act as an antioxidant. It is a mad world that bans mineral water contaminated with sodium selenite – an industrial pollutant – and then puts it in bread!

The key to success in micronutrient fortification or supplementation lies in the form of micronutrient used. For the past 18 months, Health Empowerment Through Nutrition (HETN) has been working with the South African National Tuberculosis Association to provide tuberculosis patients and their families with an inexpensive and effective daily nutritional supplement. The supplement – e’Pap – costs just 18 South African Rand (US$2.38) per person per month. It is wholegrain (maize and soya), pre-cooked, and contains the recommended daily allowance of 28 important micronutrients, in a form that enhances bioefficacy, all in a small meal portion.

Recipients’ general health and wellbeing have improved dramatically. Tuberculosis cure rates have risen by 39 per cent. Now HETN is embarking on a longitudinal study with the University of the Witwatersrand to confirm these anecdotal findings and evaluate other non-invasive indicators of nutritional status.

It is now widely accepted that the Millennium Development Goals have failed to achieve the initiation of sufficient numbers of HIV positive people on anti-retroviral medications. Africa continues to experience a rampant HIV epidemic with its associated negative social and economic impact. Antiretroviral medications should remain the major focus of treatment initiatives, but a growing body of evidence of the adjunctive role of good nutrition is being ignored.

Micronutrient supplements can and do make a real contribution to alleviating the burden of infectious disease but only if they are formulated to ensure bioefficacy. Despite this, I am not aware of any global effort to reach a consensus on appropriate micronutrient supplementation in the adjunctive management of chronic health problems.

Sadly, confusion and vested interest reign.

1 Comment

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One response to “Micronutrients must have Bioefficacy

  1. Minerals are so underrated! You have to ask why so many people of all different ages suffer from diabetes, cancer, arthritis, auto-immune disease. Read here

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