Incremental Doses of Nitrate-Rich Beetroot Juice Do Not Modify Cognitive Function and Cerebral Blood Flow in Overweight and Obese Older Adults: A 13-Week Pilot Randomised Clinical Trial

Nitrate-rich food increases nitric oxide (NO) production and may have beneficial effects on vascular, metabolic, and brain function. This pilot study tested the effects of prolonged consumption of a range of doses of dietary nitrate (NO3−), provided as beetroot juice, on cognitive function and cerebral blood flow (CBF) in overweight and obese older participants. The study had a 13-week single-blind, randomised, parallel design, and 62 overweight and obese older participants (aged 60 to 75 years) received the following interventions: (1) high NO3− (2 × 70 mL beetroot juice/day) (2) medium NO3− (70 mL beetroot juice/day), (3) low NO3− (70 mL beetroot juice on alternate days), or (4) placebo (70 mL of NO3−-depleted beetroot juice on alternate days). Cognitive functions were assessed using the Computerised Mental Performance Assessment System (COMPASS) assessment battery. CBF, monitored by concentration changes in oxygenated and deoxygenated haemoglobin, was assessed in the frontal cortex using near-infrared spectroscopy. The findings of this pilot study showed that cognitive function and CBF were not affected by supplementation with NO3−-rich beetroot juice for 13 weeks, irrespective of the NO3− dose administered. These findings require confirmation in larger studies using more sophisticated imaging methods (i.e., MRI) to determine whether prolonged dietary NO3− supplementation influences brain function in older overweight people

Acceptability and Feasibility of a 13-Week Pilot Randomised Controlled Trial Testing the Effects of Incremental Doses of Beetroot Juice in Overweight and Obese Older Adults

Nitrate-rich food can increase nitric oxide production and improve vascular and brain functions. This study examines the feasibility of a randomised controlled trial (RCT) testing the effects of prolonged consumption of different doses of dietary nitrate (NO3-) in the form of beetroot juice (BJ) in overweight and obese older participants. A single-blind, four-arm parallel pilot RCT was conducted in 62 overweight and obese (30.4 ± 4 kg/m2) older participants (mean ± standard deviation (SD), 66 ± 4 years). Participants were randomized to: (1) high-NO3- (HN: 2 × 70 mL BJ/day) (2) medium-NO3- (MN: 70 mL BJ/day), (3) low-NO3- (LN: 70 mL BJ on alternate days) or (4) Placebo (PL: 70 mL of NO3--depleted BJ on alternate days), for 13 weeks. Compliance was checked by a daily log of consumed BJ, NO3- intake, and by measuring NO3- and NO2- concentrations in plasma, saliva, and urine samples. Fifty participants completed the study. Self-reported compliance to the interventions was >90%. There were significant positive linear relationships between NO3- dose and the increase in plasma and urinary NO3- concentration (R2 = 0.71, P 0.001 and R2 = 0.46 P 0.001, respectively), but relationships between NO3- dose and changes in salivary NO3- and NO2- were non-linear (R2 = 0.35, P = 0.002 and R2 = 0.23, P = 0.007, respectively). The results confirm the feasibility of prolonged BJ supplementation in older overweight and obese adults

Protocol and recruitment results from a 13-week randomized controlled trial comparing the effects of different doses of nitrate-rich beetroot juice on cognition, cerebral blood flow and peripheral vascular function in overweight and obese older people

Background: Nitrate-rich food can increase NO production and may induce positive effects on brain function. This study examined the feasibility of a randomized clinical trial (RCT) testing the effects of prolonged consumption of incremental doses of dietary nitrate (NO ) in overweight and obese older participants. Secondary aims tested dose-dependent changes in cognitive, vascular and pulmonary functions and cerebral blood flow (CBF). Methods: This was a single blind, four-arm parallel RCT conducted in 60 overweight and obese older participants. Eligible participants were randomized to:1) high NO (140 ml of beetroot juice (BJ) per day, ~800 mg of NO /day), 2) moderate NO (70 ml of BJ per day, ~400 mg of NO /day), 3) low NO (70 ml on alternate days, ~400 mg of NO ) or 4) NO depleted (70 ml on alternate days, ~0.001 mg of NO). Measurements of cognitive, vascular and pulmonary functions and CBF were conducted at baseline and 13-weeks NO intake was assessed by six 24-h recalls, and by measuring NO intake biomarkers. Feasibility was assessed by obtaining qualitative feedback and evaluating trial recruitment, retention, compliance with study visits and measurement protocols. Results: Participant recruitment started in July 2018 and ended in April 2019. Of all the recruitment strategies that were used, advertisement of the study via Facebook generated the highest response rate. Sixty-two participants consented and were enrolled. Overall, characteristics of included participants matched our recruitment criteria. Conclusion: The findings from this study provide evidence of the acceptability and feasibility of an intervention investigating the effects of incremental doses of high-nitrate BJ over a prolonged period. Trial registration: The intervention study was registered with clinical trial ISRCTN registry (ISRCTN14746723) on 27 December 2018

The effect of bariatric surgery on dietary Behaviour, dietary recommendation Adherence, and micronutrient deficiencies one year after surgery

Bariatric surgery (BS) is associated with vitamin and mineral deficiencies, which might be augmented by low adherence to dietary guidelines and inappropriate dietary behaviours. The aim of this study was to determine the influence of BS on eating behaviour, prevalence of nutrient deficiency, level of commitment to diet, and lifestyle recommendations one-year post-BS.A cross-sectional study was conducted among adult patients who underwent BS in 2019 and had follow-up for a year. Age, gender, and clinical data were collected from the hospital system and other information was obtained from questionnaires during phone interviews. A total of 160 patients participated in the study.At 12 months, a significant increase from the baseline values in plasma levels of vitamin B12, folate, vitamin D, iron, corrected calcium, albumin, CRP, and MCV, as well as a significant decrease in BMI was observed. Adherence to dietary and lifestyle recommendations was moderate to high. Emotional, and restrained eating behaviours were moderate with 64.4%, and 77.5%, respectively. External eating was low at 58.1%.The study concluded that pre-and post-bariatric surgery nutrients should be closely monitored

Assessment of dietary nitrate intake in humans: a systematic review

The nitrate content of foods and water is highly variable, which has implications for the compilation of food-composition databases and assessment of dietary nitrate intake