Dietary factors and hypertension risk in West Africa: a systematic review and meta-analysis of observational studies

Background: Contrary to North America and Europe, the prevalence of hypertension is rising in West Africa. Although diet is implicated as a contributor to this trend, nutritional guidelines in West Africa are not tailored to address this concern. This study aimed to address this limitation by investigating dietary factors common to West Africa and evaluating their association with hypertension.

Methods: PubMed, Scopus, Web of Science, and Medline were searched to identify studies that investigated diet and hypertension in West African adults. All meta-analyses used a generic inverse-variance random effects model, with subgroup analyses by age, BMI, and study location, and were performed in R.

Results: Three thousand, two hundred ninety-eight studies were identified, of which 31 (n = 48 809 participants) satisfied inclusion criteria – all cross-sectional. Meta-analyses of the association between dietary factors and hypertension included dietary fat [odds ratio (OR) = 1.76; 95% confidence interval (95% CI) 1.44–2.14; P < 0.0001], red meat (OR = 1.51; 95% CI: 1.04–2.18; P = 0.03), junk-food (OR = 1.41; 95% CI: 1.19–1.67; P < 0.0001), dietary salt (OR = 1.25; 95% CI: 1.12–1.40; P < 0.0001), alcohol (OR = 1.17; 95% CI: 1.03–1.32; P = 0.013), and ‘fruits and vegetables’ (OR = 0.80; 95% CI: 0.24–1.17; P < 0.0001). Subgroup analyses suggested that ‘fruit and vegetable’ consumption is less protective in the elderly.

Conclusion: High consumption of dietary salt, red meat, dietary fat, junk food, and alcohol are associated with increased odds of hypertension, whereas high fruit and vegetable appear protective. This region-specific evidence will support the development of nutritional assessment tools for clinicians, patients, and researchers aiming to reduce hypertension in West Africa.