Malaria linked with genetic changes associated with ageing: Study

Malaria infection is linked with genetic changes, known to be brought about by ageing, according to a new study.

Researchers extracted genetic material from blood samples of more than 1,800 adults from the African countries of Tanzania, Botswana, Ethiopia, and Cameroon, where malaria is known to be endemic, or constantly present.

According to the 2023 World Health Organisation (WHO) Malaria report, published in ‘The Lancet Microbe’ journal, around 70 per cent of the global burden of the mosquito-borne disease is concentrated in 11 countries, including India and 10 African countries.

The team, including researchers from the University of Pennsylvania, US, analysed the DNA in white blood cells – crucial to immunity and fighting infections – and measured the lengths of telomeres present at the ends of chromosomes, which carry the genes.

Telomeres protect the chromosome ends from sticking to each other or getting frayed. They are known to shorten with age and can also help predict an individual’s risk of getting affected by ageing-related diseases and death.

“We highlight the contributions of genetic and environmental factors influencing telomere length in leukocytes (white blood cells), and we have uncovered a potential role of malaria in shortening of telomere length across sub-Saharan Africa,” said Sarah Tishkoff of the University of Pennsylvania, a co-senior author on the study published in The American Journal of Human Genetics.

The researchers found shorter telomere lengths in the white blood cells of adults indigenous to regions where malaria is highly endemic, compared to those in adults indigenous to regions with low malaria endemicity.

Malarial infection is known to cause massive destruction of white blood cells. The authors said that this process, coupled with that making new cells to restore this loss, could be a possible mechanism through which the disease shortens the length of telomeres.

They also found that the extent to which malaria was endemic to a region had a greater impact on telomere lengths, compared to environmental factors previously identified and known to impact telomere lengths.

“This association between malaria and telomere lengths of white blood cells appears larger than any other known exposure or behaviour that has been investigated in large-scale studies,” said Tishkoff.

While previous studies have suggested a link between malaria infection and telomere shortening, the researchers said it remained unknown whether repeated infections throughout life could have a lasting effect on the telomere lengths in people living in malaria-endemic regions.

The authors also said that a longitudinal (long-term) study in children and adults indigenous to regions of high and low malaria endemicity would provide more insightful information.