NSA Nutritional supplementation Trial of fruit and vegetable extracts and Vascular function (NNTV): Improvement to microvascular function using Laser Doppler Iontophoresis, following consumption of encapsulated fruit and veg powder over 12 weeks (compared with placebo), in overweight and obese human adults

BackgroundCardiovascular disease (CVD) continues to be the largest cause of death worldwide (WHO, 2014) and it presents a significant burden to the UK both in terms of health and economic costs. Diet is the cornerstone of a healthy heart and studies have shown that diet rich in fruits and vegetables (F&V) consumption exerts cardio protective effects. Numerous studies have highlighted the prognostic value of in vivo measures of macro and microvascular reactivity in predicting future coronary events and it is also present in later stages of vascular disease.AimThe aim of this study was to evaluate the effects of supplementation with encapsulated fruit and vegetable powder compared with placebo on vascular and endothelial function before and after 12 weeks of intervention when they are both given with ‘5-A-Day’ dietary advice verbally and in writing.MethodsThis was a double-blind, randomised, placebo-controlled trial that included overweight and obese but otherwise healthy participants. They were randomly allocated to one of two groups; active supplementation or placebo taken twice daily for 12 weeks. The intervention supplements were made from a total of 36 different edible food plants by blending three separate formulas of berries, fruits and vegetables. A variety of macrovascular measures were taken such as carotid intima media thickness (cIMT), flow mediated dilatation (FMD) was assessed from the right brachial artery using high-resolution ultrasound and computerised edge detection system (FMD studio, Quipu srl, Pisa, Italy). Micro-vascular function was measured using controlled Laser Doppler Iontophoresis (Moor LDI), with acetylcholine (ACh) and sodium nitroprusside (SNP), delivered to dermal forearm vessels using graded currents (0μA × 5s; 40μA × 10s; 60 μA × 30s; 100 μA × 60s).ResultsIn total, 82 participants were eligible and randomised for the NNTV study. Data are presented on 79 participants (96.3%) who completed the study. The baseline characteristics of the participants are shown in Table 1 and no significant differences were observed between the two intervention groups at baseline in age, BMI, waist circumference, fat mass percentage, total body water. No significant changes were observed between the two groups on the macrovascular measurements. However, consumption of the encapsulated fruit and veg powder capsules was found to be associated with a significant increase in endothelium dependent microvascular reactivity to acetylcholine administration at 60mA (P=0.05) (Figure 1).ConclusionBased on these findings, 12 weeks of dietary supplementation with F&V powder in encapsulated form can positively modulate microvascular endothelial function in overweight and obese adults. This supports F&V consumption as an early strategy to mitigate cardiovascular disease risk.