ABSTRACT

The study investigated the influence of Cola nitida on sweat and urine output after its consumption in relation to thirst perception, sweat rate, sweat electrolytes, urinary flow rate and urine electrolytes in the male and female human subjects. Sixty (60) non-obese volunteers (30 males and 30 females) and non-habitual Cola nut chewers, aged 18-28years were used for the study. They were sub-divided into three (3) subgroups: underweight (n=10), normal weight (n=10) and overweight (n=10) for each gender. Subjects with hypertension, kidney and heart-related conditions were excluded from the study. Three environmental conditions were involved: The normal chamber temperature, with a room temperature (RT) of 27⁰C and a relative humidity (RH) of 70%, the raised chamber temperature, with RT of 37⁰C and RH of 90%.In the aforementioned conditions, the subjects sat quietly in the sweat chamber for 20 minutes. The third condition was the normal chamber temperature with exercise, when RT and RH were maintained at 27⁰C and 70% respectively and the subjects pedalled a bicycle ergometer at moderate workload of 750J/minute for 20 minutes. The three conditions were before taking Cola nitida. Before entering the sweat chamber, the subject was told to void the bladder in preparation for the timed urine volume measurement and immediately after the experiment in the sweat chamber, the subject also voided urine for measurement. Thirst perception rating was done immediately after the 20 minutes in the sweat chamber using the visual analogue scale.0.5g/kg body weight of Cola nitida was administered to each subject and chewed as a bolus, under each of the three experimental conditions. After ingestion, 50ml of deionized water was given to each volunteer to flush the masticated Cola nitida down the gut and the subject was allowed to rest for 90 minutes before being admitted into the sweat chamber. The sweat capsule technique was used in sweat collection, after which its rate and respective electrolytes were estimated accordingly. Estimation of urine flow rate and urine electrolytes were equally carried out. The results showed that Cola nitida significantly (P<0.05) increased the sweat rate, some sweat electrolytes (such as Na⁺ and Cl^-), urine flow rate (with no significant change in urine electrolytes) and thirst perception. There were also significant reduction in both sweat and urine Ca²⁺ and Mg²⁺ concentrations. Conclusively, Cola nitida significantly influenced fluid loss via the sweat glands and the urinary system. Consequent upon the loss of fluid and electrolytes in the sweat (especially Na⁺ and Cl^-), Cola nitida stimulated the thirst perception as a compensatory mechanism to the fluid loss. Therefore, some caution should be applied in the consumption of Cola nitida by human subjects (even among those already adapted to Cola nut eating), especially under raised temperature and exercise conditions.