Biomedical subjects

Samantha Nabb

Publications and source records attributed to Samantha Nabb.

5 recordsLinked to original sources

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

The reproducibility and sensitivity of the 6-min walk test in elderly patients with chronic heart failure.

AIMS: The 6-min walk test (6-MWT) is used to estimate functional capacity. However, in elderly patients with chronic heart failure (CHF): (i) 1 year reproducibility of the 6-MWT; (ii) sensitivity of the 6-MWT to self-perceived changes in symptoms of heart failure; and (iii) implications for patient numbers required for studies using the 6-MWT as an endpoint have not been described. METHODS AND RESULTS: One thousand and seventy-seven patients with CHF, aged>60, with NYHA Class > or =II were recruited. Heart failure symptom assessment was determined using a questionnaire related to aspects of physical function, and patients performed a baseline 6-MWT, with follow-up 1 year later. Seventy-four patients with unchanged symptoms had an unchanged 6-MWT distance, with an overall intraclass correlation coefficient of 0.80 (95% CI=0.69-0.87). Four hundred and twenty-three patients reported an improvement in symptoms during follow-up. There was a negative correlation (r=-0.55; P=0.0001) between Delta symptoms and Delta 6-MWT (i.e. a reduced 6-MWT distance is associated with reduced symptom severity at follow-up). Five hundred and sixteen patients reported worsening symptoms of heart failure, a moderate inverse correlation (r=-0.53; P=0.0001) was displayed between Delta symptoms and Delta 6-MWT. For all patients, irrespective of symptom status, a high inverse correlation (r=-0.75; P=0.0001) was evident. On the basis of the data for patients with unchanged symptoms, it is calculated that to detect an increase in 6-MWT of 50 m, with 90% power, a study size of approximately 120 is required. CONCLUSION: In elderly patients with CHF, the 6-MWT shows satisfactory agreement when repeated 1 year later. Change in 6-MWT distance is sensitive to change in self-perceived symptoms of heart failure.

Aged↗

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↗

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↗