Nitrite and nitrate intake from processed meat is associated with elevated diastolic blood pressure (DBP)

Background and aims: Processed meat consumption has been linked to high blood pressure (BP), a key risk factor for cardiovascular disease (CVD), but gaps remain with regards to the ingredients which contribute to this association. This study, therefore, aimed to examine the association between nitrite and nitrate intake from processed meat with diastolic (DBP) and systolic (SBP) blood pressure, while accounting for sodium intake.

Methods: Dietary nitrite and nitrate intake from processed meat, assessed as total nitrite equivalent, was estimated for 1774 adult, processed meat consumers (≥18 years, 55.1% females) who had enrolled in the Hellenic National Nutrition and Health Survey (HNNHS). To avoid selection and reverse causality bias, associations with measured DBP and SBP were considered instead of self-reported data of hypertension presence. Participants were divided by tertile of dietary nitrite intake and by level of dietary guideline adherence for sodium (<1500; 1500-2300; ≥2300). Multiple regression models were used to examine associations with SBP and DBP, including an interaction term of nitrite with dietary sodium intake, for potential synergy.

Results: Overall, DBP increased by 3.05 mmHg (95% CI: 0, 6.06), per tertile increase in nitrite intake and 4.41 mmHg (95% CI: 0.17, 8.64) per level increase in sodium intake, when the interaction effect between nitrite and total sodium intakes was accounted for. By considering the significant synergistic effect of the two factors, DBP finally increased by 0.94 mgHg overall and 2.24 mgHg for subjects in the third tertile compared to those in the first. Also, a rise in total sodium intake of approximately 800 mg, above 1500 mg, caused a 2.30 mgHg increase in DBP. No significant correlations were found with SBP.

Conclusions: Higher nitrite and nitrate intake from processed meats contributed to the increase of DBP, but the interaction effect with total sodium intake levels should be accounted for to properly interpret the findings.