Browsing by Person "Ashmore, Sophie"

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A short study exploring the effect of the glycaemic index of the diet on energy intake and salivary steroid hormones
(2019-01-24) Al-Dujaili, Emad A. S.; Ashmore, Sophie; Tsang, Catherine
The glycaemic index or load (GI or GL) is a concept for ranking carbohydrate-rich foods based on the postprandial blood glucose response compared with a reference food (glucose). Due to the limited research investigating the effect of the GI or GL of the diet on salivary steroidal hormones, this explorative short study was conducted. 12 female participants consumed a low GI and a high GI diet for three days each, followed by a washout period between each intervention. Saliva was collected at baseline, and following the low or high GI diets. Cortisol and testosterone concentrations were measured by enzyme-linked immuno-sorbent assay (ELISA). GI and GL were significantly different between the low and high GI diets ( < 0.001). There was a small but significant increase in salivary cortisol after the high GI diet (7.38 to 10.93 ng/mL, = 0.036). No effect was observed after the low GI diet. Higher levels of testosterone were produced after the low GI diet (83.7 to 125.9 pg/mL, = 0.002), and no effect was found after the high GI diet. The total intake of calories consumed on the low GI diet was significantly lower compared to the high GI diet ( = 0.019). A low GI diet was associated with a small but significant increase in salivary testosterone, while a high GI diet increased cortisol levels. Altering the GI of the diet may influence overall energy intake and the health and wellbeing of female volunteers.
Effect of Glycaemic index of the diet on salivary cortisol and testosterone levels in females
(2007) Al-Dujaili, Emad A. S.; Ashmore, Sophie
There has been great interest in the effect of Glycaemic index (GI) of food on weight reduction, obesity, metabolic syndrome and general well being in women. The majority of research into GI was focussed towards improving blood glucose control in diabetes. Also, favourable changes in blood lipids and some beneficial effect in cancers have been reported. The aim of this pilot study is to investigate the impact of ingesting food with varying GI on salivary cortisol and testosterone levels. A cross-over design was adopted and 8 healthy female subjects volunteered for the study (20-23 years old). The project has received ethical approval by QMUC ethical committee. A diet is said to be of low GI if it has a GI of less than 55, medium GI if it has a GI of 56-69, and a high GI if it is 70 or greater. All subjects consumed a low GI or high GI diet for three days each, with a washout period separating the two. Saliva samples at baseline, after the low GI diet, washout period and high GI diet were collected at 4 different times during the day. Salivary cortisol and testosterone concentrations were measured by ELISA methods. GI was significantly different between the low and high GI diets. No significant difference in cortisol concentration was found on either diet. Significantly more testosterone was produced on the low GI diet compared to basal values (related t-test P=0.05) (see Table below). It was found that lower calories were consumed on the low GI diet compared to the high GI diet and the subject's normal diet was very similar to the high GI diet. Steroid Basal Low GI Washout High GI Unit Cortisol 8.834 11.18 9.54 9.19 ng/mL Testosterone 83.71 123.2 111.14 101.15 pg/mL In conclusion, it appears that GI of the diet consumed by females influences a variety of parameters and that a low GI diet might increase salivary testosterone concentrations. --------------------------------------------------------------------------------