[NAIROBI] A traditional African diet rich in vegetables, fibre, and fermented foods can reverse inflammation and protect against chronic diseases in just two weeks, while Western diets exacerbate these conditions, researchers say.
The research, conducted by scientists from Radboud University Medical Centre, in the Netherlands, and KCMC University, in Tanzania, found that even a short-term switch to a Western diet causes inflammation, reduces the body’s immune response to infections, and activates processes associated with lifestyle diseases.
Quirijn de Mast, an infectious diseases specialist at Radboud University Medical Centre and lead co-author of the analysis, says many areas in Sub-Saharan Africa are seeing a sharp rise in these non-communicable diseases, such as heart disease and cancer.
“Our work also underscores the importance of developing region-specific dietary recommendations, rather than simply applying guidelines from the global North without adaptation.”
Quirijn de Mast, infectious diseases specialist, Radboud University Medical Centre
“We wanted to test whether diet and the ongoing dietary transition in the region has important effects on the immune and metabolic systems.,” he told SciDev.Net.
“We found that diet was among the strongest factors associated with immune variation.”
Cardiovascular diseases are the most common cause of deaths linked to NCDs in Africa (37 per cent), and are responsible for about 13 per cent of all deaths, according to the World Health Organization (WHO).
Africa accounts for 5.7 per cent of global cancer incidence but has a larger share of deaths, at more than seven per cent, with cancer death rates projected to exceed the global average by 30 per cent in the next 20 years, the WHO says.
The African diets study involved 77 healthy men from Tanzania, both urban and rural residents.
One group of participants came from rural areas where they ate a largely plant-based diet, such as finger millet porridge, taro (a starchy root vegetable), ugali (a dish made from maize flour), okra and mchicha (a traditional vegetable dish).
The diet is common among the Chagga people of Tanzania, who live on the foothills of Mount Kilimanjaro.
During the trial, this group switched for two weeks to a Western diet that included sausages, white bread, French fries, eggs and biscuits.
Another group of participants from urban areas, who usually consumed a Western diet, did the reverse, while a third group had a daily intake of “mbege”, a fermented banana drink traditionally consumed in Tanzania. A control group maintained their usual diet.
Researchers analysed immune system function, blood inflammation markers, and metabolic processes, after the two-week intervention and again four weeks later.
Those who switched to a Western diet showed increased inflammatory proteins and reduced immune effectiveness against infections, while those adopting the traditional African diet showed reduced inflammation.
Some effects persisted even four weeks after the intervention ended, indicating that short-term dietary changes can have long-lasting impacts.
De Mast hopes the study will pave the way for future research into the health benefits of traditional diets from other regions.
“Our work also underscores the importance of developing region-specific dietary recommendations, rather than simply applying guidelines from the global North without adaptation,” he said.
“Our study adds further evidence of the adverse effects of unhealthy Western-style diets on immune and metabolic health.”
The researchers note that Sub-Saharan Africa is underrepresented in nutritional immunology research.
“One likely reason is the historical focus on infectious diseases, which have understandably received significant research attention in the region,” de Mast told SciDev.Net.
“However, there is now increasing recognition of the rapid rise in non-communicable diseases and the important role that dietary transition plays in shaping immune and metabolic health.”
He hopes to see research capacity in nutritional immunology grow across the continent in the coming years, to help close the knowledge gap.
Silvenus Konyole, associate professor of food science and nutrition at Masinde Muliro University of Science and Technology, Kenya, who did not participate in the research, supports the findings.
“Traditional African diet is mainly plant-based foods rich in antioxidants which reduce the ferocity of the oxidating agents which contribute to inflammation,” he told SciDev.Net.
This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.