Maternal intake of dietary protein from plant and animal sources and development of pharmacologically treated hypertension within 10 years after pregnancy.

Aims: To investigate associations between intake of protein from plant and animal sources and risk of development of pharmacologically treated hypertension (defined as antihypertensive medication usage >90 days after delivery) in a large population of Norwegian mothers followed up to 10 years after delivery.

Methods: Women in the Norwegian Mother, Father and Child Cohort Study (MoBa) recruited between 2004-2008 were linked to the Norwegian Prescription Database (2004-2013) to ascertain antihypertensive medication usage. Women with hypertension before pregnancy were excluded, leaving 59,967 mothers for analyses. Diet was assessed by a validated semiquantitative food frequency questionnaire in mid-pregnancy. Cox proportional hazard analyses evaluated HRs and 95% CIs for quintiles of intake in multivariable models.

Results: A total of 1,480 (2.5%) women developed hypertension within 10 years of follow-up. Intake of protein from dairy, particularly milk/yoghurt, was inversely associated with hypertension (HR for highest vs. lowest milk/yoghurt quintile: 0.76, 95% CI 0.65, 0.89, P-trend < 0.001). Intake of red meat protein was positively associated with hypertension (HR for quintile four vs. quintile one: 1.27, 95% CI 1.07, 1.51, P-trend = 0.010). No significant associations were observed for plant-based protein sources.

Conclusions: The findings suggest that intake of protein from dairy sources is inversely associated with hypertension, while protein from red meat is positively associated with developing hypertension up to ten years after pregnancy. This study provides novel contributions to the literature by examining the impact of a diverse array of plant and animal protein sources on the risk of hypertension in women.