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David Benton

Publications and source records attributed to David Benton.

At least 19 recordsLinked to original sources
PubMed2006

Effects of phosphatidylserine on exercise capacity during cycling in active males.

PURPOSE: The purpose of the study was to investigate the effects of 750 mg of soybean-derived phosphatidylserine, administered daily for 10 d, on exercise capacity, oxygen uptake kinetic response, neuroendocrine function, and feeling states during exhaustive intermittent exercise. METHODS: Following preliminary testing, fourteen active males completed a staged intermittent exercise protocol on two further occasions (T1 and T2) separated by 16 +/- 1 d. The protocol consisted of three 10-min stages of cycling at 45, 55, and 65% VO2max, followed by a final bout at 85% VO2max that was continued until exhaustion. Approximately 5 d after T1 the subjects were assigned, in a double-blind manner, to either phosphatidylserine (PS) or placebo (P). Breath-by-breath respiratory data and heart rate were continually recorded throughout the exercise protocol, and blood samples were obtained at rest, during the rest periods within the protocol (Post-55, Post-65), at the end of exercise (Post-85), 20 min after the completion of exercise (postexercise), and the day following exercise (Post-24 h). RESULTS: The main finding of this study was that supplementation had a significant effect on exercise time to exhaustion at 85% VO2max (P = 0.005). The exercise time to exhaustion in PS increased following supplementation (7:51 +/- 1:36 to 9:51 +/- 1:42 min:s, P = 0.001), whereas P remained unchanged (8:09 +/- 0:54 to 8:02 +/- 0:54 min:s, P = 0.670). Supplementation did not significantly affect oxygen kinetic mean response times (MRT(on) and MRT(off)), serum cortisol concentrations, substrate oxidation, and feeling states during the trial. CONCLUSION: This is the first study to report improved exercise capacity following phosphatidylserine supplementation. These findings suggest that phosphatidylserine might possess potential ergogenic properties.

Adult↗
PubMed2005

The influence on cognition of the interaction between the macro-nutrient content of breakfast and glucose tolerance.

Previously it has been found that both missing breakfast and having poorer glucose tolerance were associated with better memory. The present study therefore examined the impact of eight breakfasts, in a factorial design, that contained either high or low levels of carbohydrate, fat or protein. The meals were designed to vary the rate of release of glucose into the blood stream. Memory, reaction times and vigilance were assessed 30, 75 and 120 min following breakfast. Using fasting blood glucose levels as a measure of glucose tolerance, better memory was found to be associated with better glucose tolerance and the consumption of meals that more slowly release glucose into the blood. The effects of the meals on reaction times and vigilance were opposite to those with memory in that higher levels of blood glucose tended to be associated with better performance. It was concluded that individual differences in glucose tolerance interact with the glycaemic load of a meal to influence cognitive functioning.

Adolescent↗
PubMed2005

How should we measure nutrition-induced improvements in memory?

There is a basic distinction between declarative memories, which can be stated verbally, and non-declarative memory, such as how to ride a bicycle, which cannot be expressed in words. With age it is the performance of declarative memory, particularly episodic memory that requires recall of events placed in time, that declines. As memory is not a unitary phenomenon, it should be ideally monitored using a range of tests that reflect theoretical conceptions of the topic. If circumstances demand the use of a single test then a measure of episodic memory is suggested. When it proves only possible to use a rating scale it should be ensured that memory is distinguished from other aspects of cognition and that different types of memory are not confused. The tests used, and the form in which they are used, need to be chosen to be of appropriate difficulty for the sample studied. A major conclusion is that the selection of the measure of memory used in the study of a dietary intervention should never be routine. It is inevitable that the form of the test used will need to be chosen carefully for the population being studied.

Aged↗
PubMed2005

Attention, psychomotor functions and age.

Nutrition might play an important role to ameliorate or to buffer age-related declines in attention and psychomotor functions. The assessment of nutritional effects in aged subjects has to take into account that attention and psychomotor functions can be subdivided in different functions that are differentially affected by age. This paper gives an overview of changes in different facets of attention and psychomotor functions beyond fifty as well as assessment methods for attention and psychomotor performance. It also provides a review of models to explain the pattern of changes with increasing age, and discusses the problems of high performance variance and of age related confounding variables like health status. Two different approaches are discussed that analyse a performance profile and an experimentally oriented functional microanalysis of changes in performance with respect to the effects of nutrition on attention and psychomotor functions. Addressed are examples of missing age-related deficits or even age-related superiority. Caffeine and Ginseng are considered as examples to enhance performance in older persons. Results are in accordance with data on the positive role of physical fitness for mental performance in older persons. Performance of older persons can well be enhanced by functional food components or nutritional supplementation. The effects are comparable to the effects obtained in younger groups, while there is only weak evidence for specific compensatory effects in aged persons. Finally the role of nutrition for the processes of healthy aging is discussed.

Aged↗
PubMed2005

General methodological considerations for the assessment of nutritional influences on human cognitive functions.

The premise that cognitive functioning can be influenced through dietary means has gained widespread interest. The assessment of cognitive functioning is a key method to scientifically substantiate such nutritional effects on cognition. The current paper provides a basic overview of the main concepts, issues and pitfalls of human cognitive research. General methods of cognitive assessment, selection of appropriate tests, factors that may mediate task performance and issues pertaining to the interpretation of the results are discussed.

Affect↗
PubMed2005

Male body image following acquired brain injury.

The purpose of this study was to investigate body image concerns and psycho-emotional health in males with acquired brain injury (ABI). Using a between subjects study of 25 males with ABI and 25 matched controls, variables were analysed using correlations and 2 x 2 analyses of variance (ANOVAs) with head injury and injury type as independent variables. Body image and psycho-emotional health were evaluated using self-report questionnaires. Disability and cognitive impairment were measured using a mixture of self-report, cognitive testing and clinical notes. Results indicated that males with ABI had significantly lower self-esteem and body dissatisfaction on a number of items relating to physical and sexual functioning. There were significant differences in body image between stroke and TBI, but there was no corresponding relationship with psycho-emotional health. These body image differences might be explained by age. The finding that ABI has a negative effect on body image and that this relates to psycho-emotional health should be investigated further, perhaps being included in future rehabilitation strategies.

Adult↗
PubMed2005

Effects of phosphatidylserine on oxidative stress following intermittent running.

PURPOSE: The aim of the study was to investigate the effects of 750 mg of soybean-derived phosphatidylserine or a glucose polymer placebo, administered daily for 10 d, on markers of oxidative stress, perceived soreness, and muscle damage initiated by intermittent exercise (designed to simulated soccer match play) immediately followed by an exhaustive run. METHODS: Following familiarization, 16 male soccer players completed an exhaustive intermittent exercise protocol on two further occasions (T1 and T2) separated by approximately 14 d. Ten days before T2, the subjects were assigned, in a double-blind manner, to receive either phosphatidylserine (PS) or a placebo (P). Exercise time to exhaustion, sprint performance, ratings of perceived exertion, and HR were recorded throughout both main exercise trials. Venous blood samples were obtained at rest (preexercise), 15 min following exercise (postexercise), 24 h after exercise (post-24 h), and 48 h after exercise (post-48 h). RESULTS: Preexercise and postexercise concentrations of plasma gamma-tocopherol were increased following supplementation in PS, although supplementation had no effect on plasma concentrations of other nonenzymatic antioxidants (vitamin C, alpha-tocopherol, retinol, and beta-carotene). Serum cortisol concentrations, perceived soreness, markers of muscle damage (creatine kinase (CK) and myoglobin (Mb)), and lipid peroxidation (hydroperoxides and conjugated diene lag times) were elevated to an equal extent in PS and P following exhaustive exercise before and following supplementation. The changes in running times to exhaustion from T1 to T2 in PS and P were 4.2 +/- 0.7 and -3.7 +/- 4.2%, respectively (P = 0.084). CONCLUSION: Supplementation with phosphatidylserine was not effective in attenuating the cortisol response, perceived soreness, and markers of muscle damage and lipid peroxidation following exhaustive running; however, supplementation tended to increase running time to exhaustion. Therefore, future research should be undertaken to investigate the potential ergogenic properties of this supplement.

Adult↗
PubMed2004

The influence on cognition of the interactions between lecithin, carnitine and carbohydrate.

It is accepted that acetylcholine-mediated neurones modulate memory. As lecithin, carnitine and glucose all influence acetylcholine metabolism, the possibility of synergistic interactions was considered. Four hundred young adult females randomly, and under a double-blind procedure, received capsules for 3 days that contained a placebo, lecithin (1.6 g/day), carnitine (500 mg/day) or carnitine plus lecithin. A battery of cognitive tests was administered prior to taking the capsules, after 3 days of taking the supplements, and for a third time after consuming either a glucose drink or a placebo. Reaction times were more rapid when carnitine and a glucose drink were taken together. Memory was enhanced in those taking a glucose rather than placebo drink. Neither mood nor the ability to sustain attention were influenced by these procedures. The hypothesis that memory would be facilitated by offering supplements of lecithin, carnitine and glucose was not supported.

Adult↗
PubMed2004

Breakfasts that release glucose at different speeds interact with previous alcohol intake to influence cognition and mood before and after lunch.

Alcohol consumption and the glycemic load (GL) of a meal interact to influence both mood and memory. The authors compared the effects of eating a high GL lunch on mood and memory after consumption of a breakfast high in either rapidly (RAG) or slowly (SAG) available glucose. When less than 4.5 g of alcohol had been drunk the previous evening, the eating of a high RAG meal was associated with better memory later in the morning. In contrast, after more than 4.5 g of alcohol had been drunk the previous evening, the SAG meal resulted in better memory. After lunch, if more than 4.5 g alcohol had been drunk the previous evening, the RAG breakfast, but neither the SAG meal nor fasting, resulted in a more confused feeling.

Adolescent↗
PubMed2003

Carbohydrate, memory, and mood.

From a physiologic perspective, the role of glucose in brain functioning is reviewed and the effect of diet-induced changes in blood glucose on mood and cognition are outlined. Many studies have used a glucose drink or a meal composed almost entirely of carbohydrate as an experimental tool. Because pure sources of carbohydrate will be rarely consumed, the possibility that foods of different glycemic indices will modify mood and memory is briefly considered.

Affect↗
PubMed2003

On the front line.

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Attitude of Health Personnel↗
PubMed2002

The delivery rate of dietary carbohydrates affects cognitive performance in both rats and humans.

RATIONALE: Glucose is the main metabolic fuel of the brain. The rate of glucose delivery from food to the bloodstream depends on the nature of carbohydrates in the diet, which can be summarized as the glycaemic index (GI). OBJECTIVES: To assess the benefit of a low versus high GI breakfast on cognitive performances within the following 4 h. METHODS: The influence of the GI of the breakfast on verbal memory of young adults was measured throughout the morning in parallel to the assessment of blood glucose levels. The learning abilities of rats performing an operant-conditioning test 3 h after a breakfast-like meal of various GI was also examined. RESULTS: A low GI rather than high GI diet improved memory in humans, especially in the late morning (150 and 210 min after breakfast). Similarly, rats displayed better learning performance 180 min after they were fed with a low rather than high GI diet. CONCLUSION: Although performances appeared to be only remotely related to blood glucose, our data provide evidence that a low GI breakfast allows better cognitive performances later in the morning.

Adult↗
PubMed2002

Carbohydrate ingestion, blood glucose and mood.

A series of studies have reported that a high carbohydrate meal, or diets high in carbohydrate, were associated with feeling less energetic. However, after a drink containing pure sugar most studies report no effect. Meals almost exclusively carbohydrate increase the availability of tryptophan and hence serotonin synthesis in the brain, however, a small amount of protein blocks this mechanism making it an uncommon response. In many individuals, poor mood stimulates the eating of palatable high carbohydrate/high fat foods that stimulate the release of endorphins. There is a tendency for those with lower blood glucose, when performing cognitively demanding tasks, to report poorer mood. In a range of situations an association between a tendency for blood glucose levels to fall rapidly, and irritability, has been found. Differences in the ability to control blood glucose levels influence the association between carbohydrate intake and mood. There is a need in future research to contrast the impact of carbohydrate on mood in those distinguished because of their pre-existing psychological and physiological functioning.

Affect↗