The results of a randomized, double-blind, placebo-controlled trial describing the effects of taurine supplementation on blood pressure and vascular function in patients with diabetes were recently published in iScience. Taurine is a sulfur-containing semi-essential amino acid found primarily in animal foods, with past reports suggesting that it has a hypotensive effect. Despite a number of potential mechanisms, including enhanced nitric oxide production, osmoregulation of endothelial and/or vascular smooth muscle cells, etc., the evidence base for an effect in humans is limited.
One hundred and forty-four participants with type 2 diabetes received either 800 mg taurine three times per day (2.4 g total per day) or a matching placebo for 12 weeks. The primary outcome was the change in brachial-ankle pulse wave velocity (baPWV), an estimate of systemic (medium to large) arterial stiffness and cardiovascular risk, with many secondary outcomes, such as blood pressure, flow-mediated dilation (FMD), carotid intima-media thickness, and more. The primary outcome, baPWV, was reported to have significantly decreased compared to baseline with taurine supplementation (but not placebo), though surprisingly, the authors did not report the actual magnitude. They also reported a significant reduction in systolic pressure (7 mmHg) compared to baseline, as well as a significant drop in plasma uric acid levels with taurine supplementation. Endothelium-dependent vasodilation FMD and endothelium-independent vasodilation (nitroglycerin-mediated dilation) significantly improved (by 2.4% and 5.2%, respectively) compared to baseline. Additional analyses performed as a part of this study suggest that platelet calcium handling may be at least partly responsible for taurine’s apparent vascular effects.
One major limitation of this study was that the significant effects reported were in comparison to baseline, not to the placebo group, which may be a consequence of the small sample size. Nonetheless, this study and others suggest taurine could potentially have a role in improving vascular health.