Dietary Fats Substitution and Blood Pressure Levels: A Longitudinal Study in Mexican Adults

<b>Background:</b> Dietary patterns impact blood pressure (BP) levels, but the potential impact of replacing specific types of fats with proteins or carbohydrates, in isocaloric models, on BP remains unclear. <b>Objective:</b> This study evaluates the longitudinal association between the substitution of different types of fats with proteins or carbohydrates and changes in BP in a Mexican population. <b>Methods:</b> We analyzed data from 1448 adults (mean age at baseline: 45 years; 73.3% women) from the Health Workers Cohort Study, followed over 13 years. Trained personnel measured systolic (SBP) and diastolic (DBP) blood pressure following standard procedures and techniques at baseline and follow-up. Macronutrient intake was assessed with a validated semi-quantitative food frequency questionnaire. Generalized Estimating Equations (GEE) for hypertension and fixed-effects linear regression for BP were conducted using isocaloric substitution models. Each estimate reflects the effect of a 3% energy substitution of specific fats for carbohydrates or proteins. <b>Results:</b> Substituting 3% of energy intake of polyunsaturated fat (PUFA) in place of vegetable protein (β = -2.94, 95% CI: -5.02, -0.86), animal protein (β = -2.68, 95% CI: -4.73, -0.63), low glycemic index (LGI) carbohydrates (β = -2.63, 95% CI: -4.40, -0.86), and high glycemic index (HGI) carbohydrates (β = -2.52, 95% CI: -4.31, -0.74) was associated with a significant reduction in SBP. Substituting 3% of the energy intake of PUFA in place of different types of carbohydrates was associated with lower odds of hypertension. PUFA was not associated with changes in DBP. <b>Conclusions:</b> Our findings suggest that exchanging PUFA for carbohydrates or proteins is associated with reduced SBP and a lower risk of hypertension, highlighting the importance of macronutrient composition independent of total energy intake and other fat types, which may have a substantial impact at the population level.