[Note: docosahexaenoic acid or DHA is an omega-3 (n-3) polyunsaturated, 22-carbon fatty acid. It is present in abundance in certain fish and marine animal oils.]
Journal: The Journal of Nutrition. April 2007; 137(4): 973-978
Authors and affiliation: Theobald HE, Goodall AH, Sattar N, Talbot DCS, Chowienczyk PJ, Sanders TAB. Nutritional Sciences Research Division, King's College London, UK. [E-Mail: firstname.lastname@example.org ]
The intake of (n-3) long-chain PUFA is associated with a decreased risk of fatal myocardial infarction. Whether this effect is attributable to the effects of docosahexaenoic acid [22:6(n-3) (DHA)] on vascular function, particularly at intakes <1 g/d [less than 1 gram per day], is unknown.
We report a randomized, double-blind, crossover, placebo controlled trial of 0.7 g DHA/d as a purified algal derived triacylglycerol (1.5 g/d) vs. placebo (1.5 g olive oil/d) on vascular function and biochemical indices of endothelial dysfunction in 38 healthy men and women, aged 40 to 65 years.
Each treatment phase lasted 3 months, separated by a 4 month washout period.
n Supplementation increased the proportion of DHA in erythrocytes lipids by 58%, compared with placebo.
n Arterial compliance and endothelium independent and dependent responses, plasma concentrations of C-reactive protein, soluble thrombomodulin, E-selectin, von Willebrand factor antigen, and urinary microalbumin and isoprostane excretion were unaffected by treatment.
n Diastolic blood pressure decreased by 3.3 mm Hg (95% CI –6.1 to –0.6; P = 0.01).
n Heart rate tended to be 2.1 beats/min lower after DHA treatment than after the placebo period (P = 0.15).
The results indicate that a moderate increase in the daily intake of DHA to 0.7 g DHA lowers diastolic BP but does not influence indices of endothelial function or arterial stiffness in the short term.