Olive oil and reduced need for antihypertensive medications

Background: The blood pressure (BP) effects of changing the total fat intak e and saturated-unsaturated fat ratio are still controversial, despite evid ence that saturated fat-enriched diets are associated with higher BP levels . This double-blind, randomized crossover study evaluated a possible differ ence between antihypertensive effects of monounsaturated (MUFA) (extra-virg in olive oil) and polyunsaturated fatty acids (PUFA) (sunflower oil). Methods: Twenty-three hypertensive patients were assigned randomly to MUFA or PUFA diet for 6 months and then crossed over to the other diet; effects were evaluated on the basis of daily antihypertensives needed. Results: Diets high in MUFA and PUFA differed from the habitual diet for re duced total and saturated fats, whereas they differed from each other for M UFA (17.2% vs 10.5%) and PUFA content (3.8% vs 10.5%). Resting BP was signi ficantly lower (P = .05 for systolic BP; P = .01 for diastolic BP) at the e nd of the MUFA diet compared with the PUFA diet. Blood pressure responses d uring sympathetic stimulation with the cold presser test and isometric exer cise were similar. Daily drug dosage was significantly reduced during the M UFA but not the PUFA diet (-48% vs -4%, P<.005). All patients receiving the PUFA diet required antihypertensive treatment, whereas 8 of those receivin g the MUFA diet needed no drug therapy. Conclusions: A slight reduction in saturated fat intake, along with the use of extra-virgin olive oil, markedly lowers daily antihypertensive dosage r equirement, possibly through enhanced nitric oxide levels stimulated by pol yphenols.