Marine n-3 polyunsaturated fatty acids affect the blood pressure control in patients with newly diagnosed hypertension: a 1-year follow-up study

Marine long-chained n-3 polyunsaturated fatty acids (PUFA) are recognized for their cardio-protective effects, including potential lowering of blood pressure. We hypothesized that higher habitual fish intake and n-3 PUFA plasma levels were associated with lower blood pressure and being less likely to receive antihypertensive medication after one-year follow-up. In this prospective study of 115 patients, we assessed 24 h ambulatory and central blood pressure, plasma phospholipid fatty acid composition using gas chromatography and participants completed a food frequency questionnaire, including fish-eating habits. All measurements were repeated at one-year follow-up. At baseline, patients consuming fish ≥2 times per month for dinner had significantly higher plasma levels of total marine n-3 PUFA, docosahexaenoic acid and eicosapentaenoic acid as well as significantly lower central blood pressure and a trend towards lower peripheral blood pressure. At follow-up, 21 patients (18%) without antihypertensive medication had significantly higher plasma levels of n-3 PUFA, docosahexaenoic acid and eicosapentaenoic acid as well as a higher, but still acceptable 24 h ambulatory blood pressure (137/85 mmHg) compared to subjects receiving antihypertensive medication. The untreated group was more prone to take fish oil capsules and increased their plasma levels of n-3 PUFA compared to baseline. In patients with newly diagnosed, untreated hypertension, regular fish consumption was accompanied by lower blood pressure. After one year, patients without antihypertensive medication were characterized by a significant increase and higher plasma levels of n-3 PUFA. This supports a blood pressure-lowering effect and suggests an increase in marine n-3 PUFA intake as part of non-pharmacological treatment of hypertension.