Western and African Heritage Diets on Immunity

Groundbreaking Tanzania trials show that traditional plant-based diets and fermented drinks like MBEGE can reverse the inflammatory effects of Western diets.

study: Immunological and metabolic effects of the African heritage diet and western diet in men: a randomized controlled trial. Image credit: Leloojr

A recent study published in the journal Natural Medicineresearchers investigated the immunity and metabolic consequences of replacing the African heritage diet with a Western diet. They conducted a randomized controlled trial involving 77 healthy African men from rural and urban areas and were divided into three cohorts: 1. Heritage diet, 2. Western meal, 3.

The findings revealed that replacing traditional diets with Western diets increased the levels of participants in biomarkers associated with non-communicable diseases (NCDs), proinflammatory cytokine responses, and attenuated immune function. In contrast, both the transition from a Western diet to a heritage diet and the inclusion of fermented drinks are promoted. Anti-inflammatory response.

background

The prevalence of non-communicable diseases (NCDs) is at the highest ever, with the World Health Organization (WHO) estimated in 2021 that the NCD is responsible for 43 million deaths per year, roughly 75% of human deaths associated with non-infection. Research suggests that low- and middle-income countries, particularly in Asia and sub-Saharan Africa, account for the majority of these deaths (approximately 32 million), highlighting the need to identify and control drivers.

Recent research in sub-Saharan Africa highlights surprising trends. Urban adult mortality is currently above rural mortality, with incidence and prevalence of cardiovascular disease (CVD), diabetes and other diabetes with significant strains in the health care system in the region. Scientists attribute these trends to changes in urban lifestyles, particularly to shifting from traditional African “heritage” diets to calorie-dense, nutrient-rich Western foods (WD).

“Plant-based diets and fermented foods are increasingly recognized for beneficial immune and metabolic effects. In contrast, Western diets, many processed foods with high calorie density, promote metabolic dysfunction, and systemic inflammationand long-term immune cell reprogramming – a phenomenon known as “maladaptive-trained immunity” is hypothesized to be a proposed mechanism to promote NCD.

Like most traditional diets around the world (such as the Mediterranean and Japanese diets), African heritage diets are notable for their richness in green vegetables, plantains, legumes, whole grains, tubers and root crops, while traditional fermented drinks such as “mbege” can be medically healthy, such as ca.

About the research

The aim of this study is to address this knowledge gap by estimating the immunological and metabolic effects of both traditional diets (TD) and vice versa among African populations using randomized controlled trials. The two-week study was conducted in the Moshi district (Kilimanjaro, Tanzania) from April to August 2021 and consisted of young (age = 20-40 years) healthy (BMI = 18-25 kg/m²) male participants from Urshinbuejyu Village (country heritage diet) and Moshi town (urban western diet).

Participants were screened via diet recall surveys, with only rural participants protecting heritage diets, and urban participants adhere to Western diets included in further assessments. Participants' activity levels (physical activity, walking, and involvement in sports) were recorded for downstream covariate adjustment.

This study intervention consisted of: 1. Rural men (n = 23) replaced traditional diet with WD for 2 weeks. 2. Urban men (n = 22) replacing WD with heritage diet (2 weeks). And 3. Urban men add “Mbege” drinks to their diets (one liter per week per day) while maintaining a Western diet. Five men in each dietary pattern were also asked not to switch diets and act as controls. The researchers provided both Heritage Diet and WD three times a day.

Survey results

The switching from heritage diet to WD was observed to have adverse effects on several immunological and metabolic pathways, including increased inflammatory proteins and reduced cytokine responses to infection. This dietary shift was found to cause proinflammatory states of immune cells (leukocytes), alter gene expression (as shown in the transcriptome profile), upregulate inflammatory biomarkers, and attenuate immune responses to chronic inflammation (known risk factors for NCD) and microbial stimuli.

“Some of these changes lasted 4 weeks after intervention and showed persistent shock, but during this period inflammatory protein levels were partially reversed, while trained immune markers (e.g., neutrophil responses) remained altered,” the authors said.

In contrast, the transition from a Western diet to an African heritage diet has the opposite effect, demonstrated to improve immune function and promote the release of anti-inflammatory biomarkers, suggesting a potential reduction in NCD risk. MBEGE drinks were observed to show similar benefits, such as improved neutrophil response to microbial stimuli and overall metabolite profiles.

Conclusion

This study highlights the importance of dietary changes in mediating biomarkers related to NCD risk and immune performance. It validates the African heritage diet as a promoter of health and happiness by improving the immune response and attenuating chronic inflammation.

However, this study had limitations as described in the paper. The 2-week intervention period may not reflect long-term effects, with the pool of participants for all males limiting generalization, and the Western diet group gaining an average of 2.6 kg during the trial.

In contrast, it demonstrates the adverse effects of WDS on biomarkers that exacerbate NCD risk, thereby encouraging further research and public health policies to promote traditional dietary patterns (including safely prepared fermented drinks) to reduce the increasing burden of NCD-related mortality across sub-Saharan regions.