No abstract

Low plasma amyloid-β (Aβ) is linked to Alzheimer's disease. Since vitamin D cleared brain Aβ in vitro, this 8-week trial examined whether vitamin D increased plasma Aβ40. Vitamin D insufficient adults (6/18 M/F; 64.3 ± 10.9 y) were randomized to placebo or vitamin (50,000 IU/week) treatments. The vitamin group experienced greater plasma Aβ40 change than controls, +14.9 ± 12.0 and +12.8 ± 12.8 pg/mL (p = 0.045; effect size, 0.228). Change in Aβ40 for older participants (≥60 y) was +18.3 ± 33.6 and -3.2 ± 44.5 pg/mL for vitamin (n = 4) and placebo (n = 4) groups (effect size, 0.295). Thus, vitamin D may increase plasma Aβ, particularly in older adults, suggesting decreased brain Aβ.

No abstract

Nitric oxide (NO) is a primary vasodilatory factor released from endothelial cells of the peripheral vasculature. NO production is stimulated through enzymatic-dependent mechanisms via NO synthase and from dietary intake of nitrate-containing foods or supplements. We evaluated the efficacy of a nitrate-rich fruit and vegetable liquid supplement (FVS, AMPED NOx, Isagenix International LLC) versus a juice low in nitrates (prune juice, PRU) on circulating nitrates/nitrites as well as cardiovascular parameters in 45 healthy normotensive men (18–40 y). Blood pressure, flow-mediated dilation (FMD), and plasma nitrates and nitrites were measured at baseline and after two weeks of supplementation (2 oz/d). Subjects also completed questionnaires on sleep quality and mood since these measures have been associated with endothelial function. In contrast to PRU, FVS significantly increased plasma nitrates and nitrites (+67%, p < 0.001) and decreased diastolic blood pressure (−9%, p=0.029) after two weeks. The change in FMD for FVS supplementation versus PRU supplementation was not significant (+2% vs. −9%, respectively, p=0.145). Changes in sleep quality or total mood state did not differ between groups after the 2-week study. Thus, the nitrate-rich FVS supplement increased plasma NO and reduced diastolic blood pressure in young normotensive men, but increased plasma NO was not associated with improvements in FMD, mood, or sleep. This trial is registered with ClinicalTrials.gov NCT03486145.

The peripheral vasculature is important in the regulation of healthy blood pressure as endothelial cells are a source of a variety of vasoactive factors. One of the most important vasodilatory factors released from these cells is nitric oxide (NO). Production of NO is stimulated both through enzymatic‐dependent mechanisms via NO synthase as well as from dietary intake of nitrate‐containing foods or supplements such as beets or green leafy vegetables that increase NO bioavailability. Therefore, we hypothesized supplementation of a normal diet with daily consumption of a 2‐ounce beet juice energy drink (AMPED NOx; Isagenix International LLC) would increase plasma nitrates and affect cardiovascular parameters compared to a placebo drink (prune juice). Healthy male adults aged 18–40y were recruited to participate in this placebo‐controlled, randomized clinical trial as men have a greater risk of developing cardiovascular disease than pre‐menopausal women. Furthermore, women were excluded in the current study as fluctuations in progesterone are known to influence vascular reactivity. Anthropometrics, blood pressure, and fasting blood samples were collected and flow‐mediated vasodilation was measured at baseline and after one and two weeks of supplementation. Subjects also completed questionnaires on sleep quality and mood. No changes in sleep quality, mood or anthropometrics were detected following supplementation with AMPED NOx (n=24 subjects) compared to prune juice placebo (n=24 subjects). In contrast, compared to prune juice AMPED NOx significantly increased plasma nitrates and nitrites (p<0.001) while decreasing both systolic (p=0.015) and diastolic (p=0.015) blood pressures after two weeks of supplementation. There was a weak trend for AMPED NOx to increase FMD as compared to prune juice (p=0.086). The hypotensive effect of the supplement was surprising considering the average systolic and diastolic blood pressure at baseline (116±8 and 64±8 mmHg respectively). In summary, AMPED NOx is a good source of dietary nitrates and an effective strategy to lower blood pressure. Further studies are needed to determine effectiveness in a diseased population.Support or Funding InformationFunding for the study was provided by Isagenix International, LLC.