A large body of evidence from experimental, clinical and epidemiological research has demonstrated the potential benefits of long-chain n-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for cardiovascular health, such as anti-atherogenic effects, plaque stability effects, improvement of endothelial or platelet function and anti-arrhythmic effects. 1 These beneficial effects of n-3 PUFA are derived from a myriad of molecular pathways, including alteration of the physicochemical properties of cell and organelle-membrane structure and function, direct interaction with and modulation of membrane channels and proteins, regulation of gene expression through nuclear receptors and transcription factors, changes in arachidonic acid-derived eicosanoid profiles and conversion of n-3 PUFA to bioactive metabolites. 1 One of the recent topics in the field of n-3 PUFA research is its effects on blood pressure (BP) levels. Although the results of the different studies have not been consistent, several observational studies have demonstrated an association of n-3 PUFA with low BP levels and interventional studies using n-3 PUFA supplementation have shown its BP-lowering effects. The population-based International Study of Macro-and Micronutrients and Blood Pressure surveyed 4680 men and women aged 40-59 from 17 population samples and found an inverse association between BP and n-3 PUFA intake from foods while controlling for multiple possible confounders, although the estimated size of the effect was small, that is, o1.0 mm Hg with 1.9 g per day higher n-3 PUFA intake (about 1.9 g per day). 2 In interventional studies, Appel et al. 3 estimated that BP was reduced by À1.0/ À0.5 mm Hg in normotensive subjects and by À5.5/ À3.5 mm Hg in untreated hypertensive subjects for an average supplementation with 43 g per day of n-3 PUFA, suggesting that the BP-lowering effect of n-3 PUFA is stronger in hypertensive subjects. In addition, a meta-analysis showed that the anti-hypertensive effects of n-3 PUFA were dose-dependent ( À0.66/ À0.35 mm Hg g À1 n-3 PUFA) and the effects tended to be larger in middle-aged and older persons (X45 years) or those with excess clinical atherosclerotic burden. 4,5 The postulated mechanisms of the hypotensive effects of n-3 PUFA are summarized in Figure 1.In the current issue of Hypertension Research, Virtanen et al. 6 strengthen the association between n-3 PUFA and BP by using a cross-sectional analysis (n ¼ 768) that includes middle-aged and older subjects, and those who did not have a previous history of ischemic heart disease, stroke, diabetes or hypertension treatment. They showed that circulatory n-3 PUFA levels were inversely associated with systolic BP and pulse pressure but not with diastolic BP. As the present study was conducted at relatively high age (mean ageBp60 years), the clinical implication of diastolic BP seems to have less impact than systolic BP. In this study, BP was measured by the mean of six BP values in an office setting and the se...