OBJECTIVE: (1) Study 1: ROAB: To investigate the efficacy of WBE in maintaining EF and EM throughout the day alongside measures of cardiovascular outcomes in healthy older adults. A range of WBE doses were utilised to identify the optimal dose at which cognitive and cardiovascular effects occur. (2) Study 2: BEAT: To replicate alleviation of cognitive decline during a predicted post-lunch dip whilst also improving cardiovascular outcomes following acute WBE 222 mg supplementation.
METHODS: Both studies employed a randomised, double-blind, cross-over, placebo-controlled design to explore the effects of WBE intervention versus placebo on several outcomes, including EM, EF, blood pressure, and heart rate in a healthy older adult population (aged 68-75). In ROAB, 28 participants received a single dose of WBE 111 mg, 222 mg, 444 mg, or 888 mg or placebo over a 5-week period, each separated by a 1-week washout. Outcomes were measured at 0 h, 2 h, 4 h, and 6 h post intervention, with intervention occurring immediately after baseline (0 h). In BEAT, 45 participants received WBE 222 mg and placebo (1-week washout). Outcomes were measured at 0 h and 6 h (14:00) when a post-lunch dip was anticipated. This was further enhanced by consumption of lunch 1 h prior to cognitive testing. The WBE 222 mg intervention aligned with known peaks in plasma blueberry polyphenol metabolites at 2 h post dosing, which would coincide with a predicted drop in post-lunch performance.
RESULTS: ROAB: A significant dip in executive function was apparent at the 4 h timepoint for placebo only, indicating attenuation for WBE doses. Strikingly, WBE 222 mg produced acute reductions in both systolic and diastolic blood pressure compared with placebo. BEAT: EF reaction time was found to be significantly faster for WBE 222 compared to placebo at the predicted post-lunch dip (14:00), with no other notable benefits on a range of cognitive and cardiovascular outcomes.
CONCLUSIONS: These two studies indicate that WBE may have cardiovascular benefits and attenuate the natural cognitive decline observed over the course of the day, particularly when a decline is associated with a circadian rhythm-driven postprandial dip. However, it is important to acknowledge that effects were subtle, and benefits were only observed on a small number of outcomes. Further research is required to explore the utility of WBE in populations already experiencing mild cognitive impairments.
目的:(1)研究1:ROAB:研究WBE在健康老年人中全天维持EF和EM以及测量心血管结局的功效。使用一系列WBE剂量来确定发生认知和心血管影响的最佳剂量。(2)研究2:BEAT:在预期的午餐后下降期间复制认知下降的缓解,同时还改善了急性WBE222mg补充后的心血管结果。
方法:两项研究都采用了随机,双盲,cross-over,安慰剂对照设计,以探索WBE干预与安慰剂对几种结果的影响,包括EM,EF,血压,健康的老年人群(68-75岁)的心率。在ROAB,28名参与者接受了单剂量的WBE111毫克,222毫克,444毫克,或在5周内服用888毫克或安慰剂,每个间隔1周冲洗。结果在0h测量,2h,4h,干预后6小时,基线后立即进行干预(0h)。在Beat,45名参与者接受WBE222mg和安慰剂(1周洗脱)。结果是在预期午餐后下降的0小时和6小时(14:00)测量的。在认知测试之前1小时食用午餐进一步增强了这一点。WBE222mg干预与给药后2小时血浆蓝莓多酚代谢物的已知峰值对齐,这将与午餐后表演的预期下降相吻合。
结果:ROAB:仅在安慰剂的4小时时间点,执行功能明显下降,指示WBE剂量的衰减。引人注目的是,与安慰剂相比,WBE222mg可急性降低收缩压和舒张压。BEAT:在预期的午餐后下降(14:00),与安慰剂相比,WBE222的EF反应时间明显更快,对一系列认知和心血管结局没有其他显著益处。
结论:这两项研究表明,WBE可能具有心血管益处,并减轻了一天中观察到的自然认知能力下降,特别是当下降与昼夜节律驱动的餐后下降相关时。然而,重要的是要承认效果是微妙的,仅在少数结局中观察到益处.需要进一步的研究来探索WBE在已经经历轻度认知障碍的人群中的效用。