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result(s) for
"Jackson, Philippa A."
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The cognitive effects of supplementation with sunflower phosphatidyl serine in healthy children aged 8 to 12 years: a randomized controlled trial
by
Jackson, Philippa A.
,
Dodd, Fiona
,
Kennedy, David
in
Affect - drug effects
,
batteries
,
Chemical properties
2025
Background
Supplementation of the diet with phosphatidylserine (PS) is associated with cognitive and neuropsychological benefits in healthy and neuro-compromised adults. It has also been shown to mitigate symptoms of inattention in children with attention-deficit hyperactivity disorder. However, there is little data on the effects of PS in healthy children.
Objective
The aim of this randomized, placebo-controlled clinical trial was to examine the effects of sunflower-derived PS on cognitive performance in healthy, neurotypical children aged 8–12 years.
Methods
Participants received 100 mg of sunflower-derived PS daily in gummy form or a matching placebo for 12 weeks and completed an assessment battery at baseline and after 6 and 12 weeks to monitor changes in cognitive performance, mood, and sleep. Retrospectively registered at Clinicaltrials.gov; NCT05177978
Results
There were no differences in the primary or secondary outcomes in the total cohort. However, in a pre-defined subgroup analysis of children who were selected based on their constant below median performance across the cognitive tasks at baseline, PS-supplementation showed benefit on a visuospatial memory task. The supplementation with 100 mg of Sharp PS green was shown to be safe and well tolerated.
Conclusion
Although there were no differences in the primary and secondary outcomes, the findings suggest that future research should focus on children with below median performance, who are more prone to benefit from PS supplementation.
Journal Article
Differential Effects of DHA- and EPA-Rich Oils on Sleep in Healthy Young Adults: A Randomized Controlled Trial
by
Jackson, Philippa A.
,
Kennedy, David O.
,
Husberg, Cathrine
in
actigraphy
,
Adequate Intakes
,
adults
2021
Emerging evidence suggests that adequate intake of omega-3 polyunsaturated fatty acids (n-3 PUFAs), which include docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), might be associated with better sleep quality. N-3 PUFAs, which must be acquired from dietary sources, are typically consumed at suboptimal levels in Western diets. Therefore, the current placebo-controlled, double-blind, randomized trial, investigated the effects of an oil rich in either DHA or EPA on sleep quality in healthy adults who habitually consumed low amounts of oily fish. Eighty-four participants aged 25–49 years completed the 26-week intervention trial. Compared to placebo, improvements in actigraphy sleep efficiency (p = 0.030) and latency (p = 0.026) were observed following the DHA-rich oil. However, these participants also reported feeling less energetic compared to the placebo (p = 0.041), and less rested (p = 0.017), and there was a trend towards feeling less ready to perform (p = 0.075) than those given EPA-rich oil. A trend towards improved sleep efficiency was identified in the EPA-rich group compared to placebo (p = 0.087), along with a significant decrease in both total time in bed (p = 0.032) and total sleep time (p = 0.019) compared to the DHA-rich oil. No significant effects of either treatment were identified for urinary excretion of the major melatonin metabolite 6-sulfatoxymelatonin. This study was the first to demonstrate some positive effects of dietary supplementation with n-3 PUFAs in healthy adult normal sleepers, and provides novel evidence showing the differential effects of n-3 PUFA supplements rich in either DHA or EPA. Further investigation into the mechanisms underpinning these observations including the effects of n-3 PUFAs on sleep architecture are required.
Journal Article
A Randomized, Crossover Study of the Acute Cognitive and Cerebral Blood Flow Effects of Phenolic, Nitrate and Botanical Beverages in Young, Healthy Humans
by
Jackson, Philippa A.
,
Kennedy, David O.
,
Khan, Julie
in
Adolescent
,
Adult
,
Affect - drug effects
2020
Background: In whole foods, polyphenols exist alongside a wide array of other potentially bioactive phytochemicals. Yet, investigations of the effects of combinations of polyphenols with other phytochemicals are limited. Objective: The current study investigated the effects of combining extracts of beetroot, ginseng and sage with phenolic-rich apple, blueberry and coffee berry extracts. Design: This randomized, double-blind, placebo-controlled crossover design investigated three active beverages in 32 healthy adults aged 18–49 years. Each investigational beverage comprised extracts of beetroot, ginseng and sage. Each also contained a phenolic-rich extract derived from apple (containing 234 mg flavanols), blueberry (300 mg anthocyanins) or coffee berry (440 mg chlorogenic acid). Cognition, mood and CBF parameters were assessed at baseline and then again at 60, 180 and 360 min post-drink. Results: Robust effects on mood and CBF were seen for the apple and coffee berry beverages, with increased subjective energetic arousal and hemodynamic responses being observed. Fewer effects were seen with the blueberry extract beverage. Conclusions: Either the combination of beetroot, ginseng and sage was enhanced by the synergistic addition of the apple and coffee berry extract (and to a lesser extent the blueberry extract) or the former two phenolic-rich extracts were capable of evincing the robust mood and CBF effects alone.
Journal Article
The application of near infrared spectroscopy in nutritional intervention studies
2013
Functional near infrared spectroscopy (NIRS) is a non-invasive optical imaging technique used to monitor cerebral blood flow (CBF) and by proxy neuronal activation. The use of NIRS in nutritional intervention studies is a relatively novel application of this technique, with only a small, but growing, number of trials published to date. These trials-in which the effects on CBF following administration of dietary components such as caffeine, polyphenols and omega-3 polyunsaturated fatty acids are assessed-have successfully demonstrated NIRS as a sensitive measure of change in hemodynamic response during cognitive tasks in both acute and chronic treatment intervention paradigms. The existent research in this area has been limited by the constraints of the technique itself however advancements in the measurement technology, paired with studies endeavoring increased sophistication in number and locations of channels over the head should render the use of NIRS in nutritional interventions particularly valuable in advancing our understanding of the effects of nutrients and dietary components on the brain.
Journal Article
The Acute Effects of Caffeinated Black Coffee on Cognition and Mood in Healthy Young and Older Adults
by
Jackson, Philippa A.
,
Kennedy, David O.
,
Dodd, Fiona L.
in
acute effects
,
Adult
,
Affect - drug effects
2018
Cognitive and mood benefits of coffee are often attributed to caffeine. However, emerging evidence indicates behavioural effects of non-caffeine components within coffee, suggesting the potential for direct or synergistic effects of these compounds when consumed with caffeine in regular brewed coffee. The current randomised, placebo-controlled, double-blind, counterbalanced-crossover study compared the effects of regular coffee, decaffeinated coffee, and placebo on measures of cognition and mood. Age and sex effects were explored by comparing responses of older (61–80 years, N = 30) and young (20–34 years, N = 29) males and females. Computerised measures of episodic memory, working memory, attention, and subjective state were completed at baseline and 30 min post-drink. Regular coffee produced the expected effects of decreased reaction time and increased alertness when compared to placebo. When compared to decaffeinated coffee, increased digit vigilance accuracy and decreased tiredness and headache ratings were observed. Decaffeinated coffee also increased alertness when compared to placebo. Higher jittery ratings following regular coffee in young females and older males represented the only interaction of sex and age with treatment. These findings suggest behavioural activity of coffee beyond its caffeine content, raising issues with the use of decaffeinated coffee as a placebo and highlighting the need for further research into its psychoactive effects.
Journal Article
Acute Effects of a Polyphenol-Rich Leaf Extract of Mangifera indica L. (Zynamite) on Cognitive Function in Healthy Adults: A Double-Blind, Placebo-Controlled Crossover Study
2020
Extracts made from the leaves of the mango food plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to particularly high levels of the polyphenol mangiferin. In rodent models, oral mangiferin protects cognitive function and brain tissue from a number of challenges and modulates cerebro-electrical activity. Recent evidence has confirmed the latter effect in healthy humans following a mangiferin-rich mango leaf extract using quantitative electroencephalography (EEG). The current study therefore investigated the effects of a single dose of mango leaf extract, standardised to contain >60% mangiferin (Zynamite®), on cognitive function and mood. This study adopted a double-blind, placebo-controlled cross-over design in which 70 healthy young adults (18 to 45 years) received 300 mg mango leaf extract and a matched placebo, on separate occasions, separated by at least 7 days. On each occasion, cognitive/mood assessments were undertaken pre-dose and at 30 min, 3 h and 5 h post-dose using the Computerised Mental Performance Assessment System (COMPASS) assessment battery and the Profile of Mood States (POMS). The results showed that a single dose of 300 mg mango leaf extract significantly improved performance accuracy across the tasks in the battery, with domain-specific effects seen in terms of enhanced performance on an ‘Accuracy of Attention’ factor and an ‘Episodic Memory’ factor. Performance was also improved across all three tasks (Rapid Visual Information Processing, Serial 3s and Serial 7s subtraction tasks) that make up the Cognitive Demand Battery sub-section of the assessment. All of these cognitive benefits were seen across the post-dose assessments (30 min, 3 h, 5 h). There were no interpretable treatment related effects on mood. These results provide the first demonstration of cognition enhancement following consumption of mango leaf extract and add to previous research showing that polyphenols and polyphenol rich extracts can improve brain function.
Journal Article
The Acute and Chronic Cognitive and Cerebral Blood Flow Effects of a Sideritis scardica (Greek Mountain Tea) Extract: A Double Blind, Randomized, Placebo Controlled, Parallel Groups Study in Healthy Humans
2018
Background: The presence of polyphenols such as hydroxy-cinnamic acids and flavonoids in Sideritis scardica (Greek mountain tea) are likely responsible for the cognitive and mood effects of its consumption and this could be underpinned by the ability of such polyphenols to prevent monoamine neurotransmitter reuptake and to increase cerebral blood flow (CBF). Objective: The current study extends the small amount of Sideritis scardica literature in humans by assessing both cognitive and mood outcomes in a sample of older adults, as well as blood pressure (BP) and CBF, in a subsample, utilizing near-infrared spectroscopy (NIRS). Design: This randomized, double-blind, placebo-controlled, parallel groups trial randomized N = 155, 50–70-year-old male and female participants who were assessed for the cognitive (N = 140), mood (N = 142), BP (N = 133) and CBF (N = 57) effects of two doses of Greek mountain tea (475 and 950 mg) as well as an active control of 240 mg Ginkgo biloba, and a placebo control, following acute consumption (Day 1) and following a month-long consumption period (Day 28). Results: Relative to the placebo control, 950 mg Greek mountain tea evinced significantly fewer false alarms on the Rapid Visual Information Processing (RVIP) task on Day 28 and significantly reduced state anxiety following 28 days consumption (relative also to the active, Ginkgo control). This higher dose of Greek mountain tea also attenuated a reduction in accuracy on the picture recognition task, on Day 1 and Day 28, relative to Ginkgo and both doses of Greek mountain tea trended towards significantly faster speed of attention on both days, relative to Ginkgo. Both doses of Greek mountain tea, relative to placebo, increased oxygenated haemoglobin (HbO) and oxygen saturation (Ox%) in the prefrontal cortex during completion of cognitively demanding tasks on Day 1. The higher dose also evinced greater levels of total (THb) and deoxygenated (Hb) haemoglobin on Day 1 but no additional effects were seen on CBF on Day 28 following either dose of Greek mountain tea. Ginkgo biloba led to lower levels of Ox% and higher levels of Hb on Day 1 and lower levels of both HbO and THb on Day 28. Conclusions: The significantly improved cognitive performance following Greek mountain tea on Day 1 could be due to significant modulation of the CBF response. However, these improvements on Day 28 are more likely to be due to the reductions in state anxiety and, taken together, suggests that the former mechanism is more likely to facilitate acute cognitive effects and the latter more likely to underpin more prolonged cognitive improvements.
Journal Article
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
by
Jackson, Philippa A.
,
Kennedy, David O.
,
Lang, Stefanie C.
in
Adult
,
Affect - drug effects
,
Aged
2020
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.
Journal Article
The Acute and Chronic Cognitive Effects of a Sage Extract: A Randomized, Placebo Controlled Study in Healthy Humans
2021
The sage (Salvia) plant contains a host of terpenes and phenolics which interact with mechanisms pertinent to brain function and improve aspects of cognitive performance. However, previous studies in humans have looked at these phytochemicals in isolation and following acute consumption only. A preclinical in vivo study in rodents, however, has demonstrated improved cognitive outcomes following 2-week consumption of CogniviaTM, a proprietary extract of both Salvia officinalis polyphenols and Salvia lavandulaefolia terpenoids, suggesting that a combination of phytochemicals from sage might be more efficacious over a longer period of time. The current study investigated the impact of this sage combination on cognitive functions in humans with acute and chronic outcomes. Participants (n = 94, 25 M, 69 F, 30–60 years old) took part in this randomised, double-blind, placebo-controlled, parallel groups design where a comprehensive array of cognitions were assessed 120- and 240-min post-dose acutely and following 29-day supplementation with either 600 mg of the sage combination or placebo. A consistent, significant benefit of the sage combination was observed throughout working memory and accuracy task outcome measures (specifically on the Corsi Blocks, Numeric Working Memory, and Name to Face Recall tasks) both acutely (i.e., changes within day 1 and day 29) and chronically (i.e., changes between day 1 to day 29). These results fall slightly outside of those reported previously with single Salvia administration, and therefore, a follow-up study with the single and combined extracts is required to confirm how these effects differ within the same cohort.
Journal Article
Acute Cognitive Performance and Mood Effects of Coffeeberry Extract: A Randomized, Double Blind, Placebo-Controlled Crossover Study in Healthy Humans
2023
Background: Coffeeberry extract, rich in chlorogenic acids, shows promise in improving mood and cognition, particularly when co-supplemented with phenolic compounds. However, limited work has considered the effects of coffeeberry in isolation, especially at low doses. Objective: The current study investigated the effect of low and moderate doses of coffeeberry extract on cognition and mood. Design: This randomized, double-blind, placebo-controlled crossover design investigated three active beverages on a sample of 72 healthy adults aged 18–49 years. The investigational beverages contained 100 mg or 300 mg coffeeberry extract (standardized to 40% chlorogenic acid), or 75 mg caffeine (positive control). Cognition, mood, and subjective energy were measured at baseline and then again at 60 and 120 min post-treatment. Results: Analysis revealed no effect of 300 mg coffeeberry extract, while 100 mg resulted in increased mental fatigue during the performance of cognitively demanding tasks (p = 0.025) and decreased accuracy on a task of sustained attention (p = 0.003), compared to placebo, at 60 min post dose. Conclusions: Administration of 100 mg and 300 mg coffeeberry extracts revealed limited, transient negative effects following 100 mg coffeeberry. Given the large number of outcome measures analysed and the absence of findings following the 300 mg dose, these negative findings should be interpreted with caution. Overall, the findings of the current study suggest that coffeeberry extract at a low or moderate dose does not have a beneficial effect on mood, mental and physical energy levels, or cognition; higher doses, as have been administered previously, may be more effective.
Journal Article