Low availability of selenium, an
essential human micronutrient, in Malawian soils is responsible for its
deficiency among the country's population, a study has found.
Researchers from Malawi, New Zealand
and the United Kingdom sought to establish both whether selenium content in
different Malawian soils affects the mineral content of food crops grown in
them, and its ultimate influence on the status of human health.
Selenium is incorporated into
proteins, creating selenoproteins that form part of the human immune system
that keeps people healthy.
In a country where 12 per cent of
people aged 15-49 years old have HIV, selenium deficiency can be associated
with low CD4 count, disease progression and the risk of death, says Alexander
Kalimbira, researcher and senior lecturer in human nutrition at the Lilongwe
University of Agriculture and Natural Resources, Malawi.
"We analysed blood and urine
samples of 120 women aged 18-50 years from Mzuzu in the north [of the country]
and the Shire Valley Agricultural Development Divisions in the south,"
says Kalimbira, who was involved in the research.
The researchers found widespread
selenium drficiency among the women, apparently resulting from unfavourable
soil factors such as land degradation and poor farming practices such as
cultivation along steep slopes where there are fewer plants.
They suggest that through existing
fertiliser subsidy programmes in Malawi there is potential for a public health
intervention to enrich inorganic fertilisers with selenium. They hope that
through doing this its presence in the country's soil will lead to high intake
by plants, and thus combat nationwide selenium deficiency.
Stacia Nording, a nutritionist and
dietician at a Malawi based Never Ending Food, a permaculture and sustainable
nutrition advocacy group, supports the researchers' recommendation to enrich
Malawi's soil. However, she believes that this should be done organically.
According to Nording, it is possible
to enrich soils with selenium through natural means. For example, she says,
selenium can be sourced through mushrooms that feed on dead organic material
rather than through fertiliser fortification.
Calestous Juma, professor of the
Practice of International Development at the Harvard Kennedy School, United
States, says: "The area of micronutrients in human health is starting to
receive considerable attention and much of the research will need to be carried
out locally. This means that African countries will have to start thinking more
seriously about increasing research and fostering cooperation for such
activities".
The research was published last
month (12 March) in Scientific Reports, an open access journal published
by Nature.
No comments:
Post a Comment