RESUMEN
Palm oil is one of the most widely employed cooking oils in Nigeria today. This study compares the effects of long term consumption of the two forms of palm oil – fresh palm oil (FPO) and thermally oxidized palm oil (TPO) on serum electrolytes, creatinine and urea, which gives vital information on the state of the renal system. Eighteen male New Zealand rabbits weighing 750 – 1000 g were used for this study. They animals were randomly assigned one of three groups (n = 6) thus; control group, FPO fed group and TPO fed group. The control group received animal feed and clean water only. Fresh palm oil group received animal feed mixed with fresh palm oil in the ratio 85:15g respectively, TPO fed group received animal feed mixed with thermoxidised palm oil in the ratio 85:15g respectively. The feeding lasted for 6 months. Food intake, water intake and body weight were measured daily. At the end of the feeding period, the animals were sacrificed under chloroform anaesthesia and blood was collected for assessment of serum electrolytes, creatinine and urea. Results obtained showed that serum concentration of sodium was significantly (p<0.001) lower in FPO fed group, compared with control, but significantly (p<0.05) higher in TPO fed group, compared with control. Serum concentration of sodium was also significantly (p<0.001) higher in TPO fed group, compared with FPO fed group. Serum concentration of chloride was significantly lower in FPO fed group compared with control (p<0.05) and TPO fed group (p<0.001). Bicarbonate concentration was significantly (p<0.05) lower in FPO fed group, compared with control. Creatinine concentration was significantly higher (p<0.05) in TPO fed group, compared with control and FPO fed group. The observed changes in serum electrolyte and creatinine concentrations following 6 months of feeding was more in TPO fed group than FPO fed group, and is possibly detrimental to electrolyte balance.
RESUMEN
Aim: Long term consumption of dietary oils has been implicated in the etiology of hypertension. This study seeks to compare the effects of long term consumption of fresh palm oil (FPO) and thermoxidized palm oil (TPO) on baroreceptor reflex sensitivity (BRS), which is responsible for short term regulation of blood pressure. Methodology: The design of this study involved the use of eighteen, male, five month old New Zealand rabbits weighing 750 – 1000 g. They were divided into three groups (n = 6) as follows; control group (received normal animal feed only), FPO diet – fed group (received animal feed mixed with fresh palm oil in the ratio 85:15, respectively) and TPO diet – fed group (received animal feed mixed with thermoxidised palm oil in the ratio 85:15, respectively). The animals were fed for 6 months, after which they were used for the various experiments. Results: Mean daily food and water intake in FPO and TPO fed groups was significantly (p<0.001) lower compared with control. Heart rate for FPO group was significantly higher than the control (p<0.001) and TPO (p<0.01) group. Basal systolic and diastolic blood pressures were significantly higher in TPO group than in the FPO and control (p<0.05) group. The FPO group also had a significantly lower basal systolic (p<0.01) and diastolic pressure (p<0.001) than the control group. The basal pulse pressure was significantly lower in the FPO group than the control (p<0.001) and the TPO group (p<0.01). The mean arterial pressure (MAP) for TPO group was significantly higher (p<0.001) than that of control and FPO groups. The baroreflex sensitivity for FPO group was significantly reduced compared with control (p<0.01) and TPO group (p<0.05). The TPO group showed a significantly lower (p<0.01) baroreflex sensitivity, compared with control. Conclusion: This study observed that chronic consumption of both fresh and thermoxidised palm oil diets caused a significant reduction in carotid baroreceptor reflex sensitivity. However, reduction in BRS was more in fresh palm oil – diet fed group, than the thermally oxidized palm oil diet – fed.