Immune and metabolic effects of African heritage diets versus Western diets in men: a randomized controlled trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 40181181 · doi:10.1038/s41591-025-03602-0
What was done
A randomized controlled trial conducted in the Kilimanjaro region of Northern Tanzania evaluated the immune and metabolic consequences of switching between a Kilimanjaro heritage-style diet and a Western-style diet for 2 weeks, as well as consuming a traditional fermented banana beverage ('Mbege') for 1 week. The study enrolled 77 healthy young male volunteers from rural and urban areas. Primary outcomes were alterations in immune profiles (including whole-blood cytokine responses to microbial stimulation) and metabolic profiles measured before and after interventions, as well as at a 4-week follow-up.
What was found
The abstract reports directional findings without specific numerical values, effect sizes, or confidence intervals. Switching from the heritage-style to the Western-style diet altered metabolic pathways linked to noncommunicable diseases, promoted a pro-inflammatory state, and impaired whole-blood cytokine responses to microbial stimulation. Conversely, switching from the Western-style to the heritage-style diet or consuming the fermented banana beverage produced largely anti-inflammatory effects. Several observed immune and metabolic changes persisted at the 4-week follow-up.
Why it matters
This trial provides direct experimental evidence that transitioning from traditional African heritage diets to Western dietary patterns rapidly triggers adverse immune and metabolic shifts. It underscores the public health value of preserving indigenous dietary practices to prevent noncommunicable diseases in sub-Saharan Africa.
Limits
The abstract reports no numerical data, effect sizes, or p-values. The sample size was relatively small (n = 77) and restricted exclusively to young, healthy male participants from a single region in Tanzania, limiting generalizability to females, older populations, and other geographic groups. Furthermore, the intervention periods were short (1 to 2 weeks).
Cited by
- supports A Nature Medicine study of Tanzanians showed that individuals eating a traditional African diet had lower inflammatory potential and lower gene activation in their immune cells compared to those consuming a Westernized diet.