Chronic effects of a wild green oat extract supplementation on cognitive performance in older adults: a randomised, double-blind, placebo-controlled, crossover trial

Dietary supplementation with a wild green oat extract (Avena sativa L.) to improve wellness and wellbeing during smoking reduction or cessation: a randomized double-blind controlled study

Objective

Smoking reduction or cessation are critical public health goals, given the well-documented risks of tobacco use to health. Reducing smoking frequency and cessation entirely are challenging due to nicotine addiction and withdrawal symptoms, which can significantly affect mental wellness and overall wellbeing. Previous research has suggested that certain dietary supplements may support smoking cessation and reduction efforts by mitigating these adverse effects. The objective of this study was to assess the effect of supplementation with 900 mg/day of Neuravena®, a green oat extract (GOE) of Avena sativa L., in enhancing wellness and wellbeing during a smoking reduction or cessation experience.

Methods

This was an 8-week randomized, double-blind, placebo-controlled study, ClinicalTrials Identifier: NCT04749017 (https://classic.clinicaltrials.gov/ct2/show/NCT04749017). Participants were assigned to one of the study groups, 72 participants were assigned to GOE and 73 to placebo. The subjects were followed for 8-weeks intervention period as well as an additional 4-week follow-up period. At subsequent visits, they underwent clinical assessments including assessments of quality of life, perceived stress, depression, nicotine dependence, anxiety, cognitive performance, and specific assessments of craving intensity.

Results

GOE was associated with greater improvements in elements of the abbreviated World Health Organization Quality of Life (WHOQOL-BREF) questionnaire as compared with placebo. Similar results were obtained from the SF-36 questionnaire and a visual QoL analogue scale (VAS). Perceived stress levels showed greater decline from baseline among the GOE supplemented participants as compared to placebo. Sleep quality parameters improved with GOE supplementation and worsened in the placebo group. At the end of the intervention period, the percentage of successful reducers (defined as >20% reduction in daily cigarettes) was higher in the GOE group as compared to placebo (66.7% vs. 49.3%, p = 0.034). The improvements from baseline in QoL measures in the GOE group persisted at 4 weeks after termination of the intervention.

Conclusion

GOE supplementation demonstrated greater improvements in quality of life measures, stress and sleep related parameters during a smoking reduction or cessation experience and the product was shown to be safe and well tolerated.

Effect of Avena sativa (Oats) on cognitive function: A systematic review of randomized controlled trials

BACKGROUND AND AIM

The effect of polyphenol-rich diets or supplements on cognitive function remains a contentious topic. The objective of this study was to investigate the effects of Avena sativa (oat extracts) on cognitive function among healthy adults.

METHODS

A structured literature search was undertaken using PubMed, Web of Science, and Scopus from the database's establishment until March 17, 2022. Data on cognitive function, regarding accuracy and speed of performance, were gathered from randomized controlled trials (RCTs) that investigated the acute or chronic effects of Avena sativa in healthy subjects. The Cochrane Collaboration risk-of-bias tool was used to assess the quality of included studies.

RESULTS

We included six RCTs, of which three were crossover designs, with a total of 287 individuals. Four studies investigated the acute effect of Avena sativa, while two investigated its chronic effect. Acute ingestion of Avena sativa appeared to positively influence the accuracy and speed of performance. While short-term chronic supplementation resulted in a significant improvement in cognitive function, long-term chronic supplementation did not. Overall, the evidence was of average quality.

CONCLUSION

Acute supplementation with Avena sativa may improve cognitive function in healthy volunteers. Given the small number of trials included and the disparity of the intervention dose, the conclusions of this study should be interpreted with caution. More high-quality, long-term studies are warranted.

Acute and Chronic Effects of Green Oat (Avena sativa) Extract on Cognitive Function and Mood during a Laboratory Stressor in Healthy Adults: A Randomised, Double-Blind, Placebo-Controlled Study in Healthy Humans

Green oat (Avena sativa) extracts contain several groups of potentially psychoactive phytochemicals. Previous research has demonstrated improvements in cognitive function following a single dose of these extracts, but not following chronic supplementation. Additionally, whilst green oat extracts contain phytochemicals that may improve mood or protect against stress, for instance species-specific triterpene saponins, to date this possibility has not been examined. The current study investigated the effects of a single dose and four weeks of administration of a novel, Avena sativa herbal extract (cognitaven^®) on cognitive function and mood, and changes in psychological state during a laboratory stressor. The study adopted a dose-ranging, double-blind, randomised, parallel groups design in which 132 healthy males and females (35 to 65 years) received either 430 mg, 860 mg, 1290 mg green oat extract or placebo for 29 days. Assessments of cognitive function, mood and changes in psychological state during a laboratory stressor (Observed Multitasking Stressor) were undertaken pre-dose and at 2 h and 4 h post-dose on the first (Day 1) and last days (Day 29) of supplementation. The results showed that both a single dose of 1290 mg and, to a greater extent, supplementation for four weeks with both 430 mg and 1290 mg green oat extract resulted in significantly improved performance on a computerised version of the Corsi Blocks working memory task and a multitasking task (verbal serial subtractions and computerised tracking) in comparison to placebo. After four weeks, the highest dose also decreased the physiological response to the stressor in terms of electrodermal activity. There were no treatment-related effects on mood. These results confirm the acute cognitive effects of Avena sativa extracts and are the first to demonstrate that chronic supplementation can benefit cognitive function and modulate the physiological response to a stressor.

Acute effects of a wild green-oat (Avena sativa) extract on cognitive function in middle-aged adults: A double-blind, placebo-controlled, within-subjects trial

OBJECTIVES

A wild green-oats extract (Neuravena^®) containing a range of potentially bioactive components, including flavonoids and triterpene saponins, has previously been shown to enhance animal stress responses and memory, and improve cognitive performance in humans at a dose of 1600 mg. Methods This double-blind, placebo-controlled, counterbalanced cross-over study assessed the effects of single doses of the green-oat extract (GOE) across a broad range of cognitive domains in healthy adults aged 40-65 years who self-reported that they felt that their memory had declined with age. Participants attended on six occasions, receiving a single dose of either placebo, 800, or 1600 mg GOE on each occasion, with the counterbalanced order of treatments repeated twice for each participant. Cognitive function was assessed with a range of computerized tasks measuring attention, spatial/working/episodic memory, and executive function pre-dose and at 1, 2.5, 4, and 6 hours post-dose. Results The results showed that 800mg GOE increased the speed of performance across post-dose assessments on a global measure including data from all of the timed tasks. It also improved performance of a delayed word recall task in terms of errors and an executive function task (Peg and Ball) in terms of decreased thinking time and overall completion time. Working memory span (Corsi blocks) was also increased, but only on the second occasion that this dose was taken. Discussion These results confirm the acute cognitive effects of GOE seen in previous research, and suggest that the optimal dose lies at or below 800 mg.

Plasma levels of tumor necrosis factor-α in adolescent idiopathic scoliosis patients serve as a predictor for the incidence of early postoperative cognitive dysfunction following orthopedic surgery

The aim of the present study was to evaluate whether the levels of the plasma biomarkers, cortisol, interleukin (IL)-1β, IL-6, IL-10 and tumor necrosis factor (TNF)-α, change in adolescent idiopathic scoliosis patients with postoperative cognitive dysfunction (POCD); thus, may serve as predictive factors for POCD. In total, 75 adolescent scoliosis patients, aged between 11 and 18 years and categorized as American Society of Anesthesiologists classification I or II, were scheduled for orthopedic surgery with general anesthesia. Blood samples were collected on the day of admission and at day 2 following surgery. The plasma levels of IL-1β, IL-6, IL-10 and TNF-α were measured using an enzyme-linked immunosorbent assay, while the concentrations of cortisol were determined using a radioimmunoassay. Cognitive function was assessed one day prior to and at day 7 following the surgery in a quiet room with the guidance of a Chinese version protocol. In total, 66 patients completed the sample collection and neurocognitive tests. According to the criteria for the diagnosis of POCD, 19 patients (28.8%) developed POCD within seven days of surgery. No statistically significant differences were observed in the baseline concentrations of cortisol, TNF-α, IL-1β, IL-10 or IL-6 between the POCD and non-POCD groups. However, the baseline plasma level of TNF-α on day 2 in the POCD group was found to be higher compared with the non-POCD group. In addition, at day 2 after surgery, the concentration of cortisol in the non-POCD group was higher compared with the POCD group. Therefore, the plasma level of TNF-α in adolescent idiopathic scoliosis patients at day 2 following orthopedic surgery may be a predictor for the incidence of early POCD.

Nutraceuticals for older people: facts, fictions and gaps in knowledge

In the last decades nutraceuticals have entered the health market as an easy and attractive means of preventing diseases. These products are of interest for an increasingly health-concerned society and may be especially relevant for preventing or delaying a number of age-related diseases, i.e. arthritis, cancer, metabolic and cardiovascular diseases, osteoporosis, cataracts, brain disorders, etc. Nutraceuticals are marketed in a variety of forms, composition and potential applications which have made their definition ambiguous and their use uncontrolled and poorly funded. Although epidemiological, animal and in vitro studies have given evidence of the potential benefits of some of these nutraceuticals or of their components, definitive proof of their effects in appropriate human clinical trials is still lacking in most cases, more critically among people above 65 years of age. We cover the well-established nutraceuticals (polyvitamins, omega-3 fatty acids, etc.) and will focus on many other 'novel' commercial nutraceuticals where the scientific evidence is more limited (food extracts, polyphenols, carotenoids, etc.). Solid scientific evidence has been reported only for a few nutraceuticals, which have some health claims approved by the European Food Safety Authority (EFSA). Further well-designed trials are needed to improve the current knowledge on the health benefits of nutraceuticals in the elderly. Overall, there are some facts, a lot of fiction and many gaps in the knowledge of nutraceutical benefits.