The association between dietary macronutrient distribution and mortality in an African cohort

Optimal nutrition is essential for reducing both all-cause and cardiovascular disease (CVD) mortality. Existing research highlights the importance of macronutrient type and quality in this context, with limited evidence in non-Western populations. We aimed to determine the association between macronutrient distribution and all-cause and CVD mortality in an African population as well as the contribution of the respective food sources. This cohort consisted of 1737 African men and women with a median observational time of 13 years, resulting in 19 456.6 person-years. CVD-related ICD-10 codes (I00-I99) were included when considering CVD mortality. Substitution analysis using partition and nutrient-density models assessed the relationship between macronutrient distribution and mortality. Higher intakes of complex carbohydrates (CHO), animal protein, total fat, and monounsaturated fatty acids (MUFA) were associated with decreased all-cause mortality risk. The partition model also revealed that substituting 200 calories (kcal) of plant protein with animal protein significantly reduced all-cause mortality risk by 39% to 33% (Model 1-3). In addition, the isocaloric substitution of 10% total energy from total fat with total carbohydrates led to a 17% reduction in all-cause mortality risk (HR 0.83; 95% CI 0.72, 0.96). No significant associations with CVD mortality were found. These findings partially agree with, yet also oppose previous studies, emphasising the need for population-specific data. Research from high-income European populations may not directly apply to African contexts due to food insecurity, reliance on staple-based diets with low-quality plant proteins and lean, higher quality animal protein sources, as well as differences in CVD disease aetiology.