Calibrating Effects of a Novel Supplement Strategy on Vascular Measures of Aging
The supplement industry exists in its present vocal form because most people don't care about effect size at all. Or accuracy. Or truth. They hear that something has an effect, and run out to buy it. The industry marketing is tuned to take advantage of this aspect of human nature. But what are the expected effect sizes for the better end of supplement strategies? This study reports on the effects of a combination supplement that rolls in some of the more interesting compounds assessed in recent years, including glycine - though of course at much lower doses than those used in the small GlyNAC study that showed quite surprisingly large benefits in old patients. Since no-one cares about effect size, why go to the trouble of delivering doses larger than are convenient? Nonetheless, the study results provide an illustrative data point to add to others when managing expectations regarding what to expect from a sane strategy of supplementation.
A growing body of evidence suggests that specific nutritional bioactives, such as polyphenols, amino acids, and micronutrients, can beneficially modulate nitric oxide signalling, oxidative stress, autonomic balance, and endothelial health. While several compounds have shown efficacy individually, vascular ageing is driven by multiple converging mechanisms, raising the possibility that broader, multi-target approaches may provide additive or synergistic benefits. Because vascular ageing arises from several interacting mechanisms, single-compound interventions may only influence part of the underlying biology. A multi-component nutritional approach allows targeting several complementary pathways simultaneously while using lower doses of each ingredient, which may improve tolerability and minimize the risk of dose-related side effects. However, clinical evidence evaluating such combined strategies in humans remains limited.
We hypothesized that daily consumption of a multi-component nutritional supplement would improve endothelial function and related indices of vascular ageing compared with control. Accordingly, in this randomized, double-blind, controlled trial, we tested whether a formulation selected to combine ingredients with relevance to complementary biological pathways implicated in vascular ageing was associated with changes in endothelial function, arterial stiffness, haemodynamics, lipid profile, and estimated cardiovascular risk in healthy middle-aged and older adults (≥40 years).
The primary outcome was change in brachial artery flow-mediated dilation (FMD). Secondary outcomes included pulse wave velocity (PWV), peripheral and central blood pressure, augmentation index, lipid profile, and estimated 10-year cardiovascular risk (SCORE2/SCORE2-OP). Sixty-one participants (baseline SCORE2/SCORE2-OP 3.6 ± 2.9%) were randomized (33 actives; 28 controls); 43 completed both visits (24 vs. 19). Compared with control, the supplement improved endothelial function (ΔΔFMD at 6 months +2.9% ) and reduced arterial stiffness (ΔΔPWV -1.18 m/s). Peripheral systolic blood pressure (SBP) decreased (ΔΔSBP -6.1 mmHg). Lipids were unchanged. Estimated 10-year cardiovascular risk decreased (ΔΔSCORE2/SCORE2-OP -0.45%).