SUPPLEMENTATION WITH VIRGIN COCONUT OIL: CAN IT REALLY REDUCE COGNITIVE DECLINE?

Abstract

The sudden decrease in bioavailable estrogen in menopause puts ageing females at increased risk of cognitive decline. Consumption of virgin coconut oil (VCO) which has been “classified as a highly nutritious functional food” has gained popularity recently due to claims of beneficial effects in people with cognitive impairment. This study was designed to compare the effect of VCO supplementation on learning and memory between mature, cycling and aged, non-cycling rats. Twelve 15-month old and twelve 22-month old female Sprague-Dawley rats completed the study. Vaginal smear cytology determined estrous cycle staging to identify cycling and non-cycling rats. A modified discriminative learning paradigm utilizing a Y-maze was adopted. Number of entries and time spent determined arm preference during a 3-minute maze exploration. Rats that exhibited preference (>75%) for the black arm of the maze were selected. Each age cohort was randomly assigned to either a VCO-treated or non-VCO (control) group (n=6). Treated rats were administered a daily oral dose of 1.42 ml/kg of cold pressed VCO. In pre-training, rats were confined to the non-preferred, white arm of the maze and learnt to associate the presentation of a tone with reward. Rats were then allowed 4 trials daily over 3 weeks and rewarded only if they entered the non-preferred arm within 15 seconds after presentation of a tone (i.e. correct response). Time to attain at least 75% correct responses (acquisition latency) was used to assess learning. Memory retention of the learnt task was assessed in all groups following a 2-week break. Data were analyzed using Students’ T-test and ANOVA. Cycling rats had lower acquisition latencies and significantly higher correct response rates than non-cycling rats (p=0.04). Cycling VCO-treated rats exhibited a significant enhancement of learning (p=0.04) compared with non-supplemented controls. VCO supplementation showed no improvement in memory retention across all groups, however VCO treated cycling rats had higher response rates than their non-cycling counterparts. VCO supplementation produced a small positive effect on cognition overall, but appears to be more effective when supplemented during the cycling period when estrogen levels are normal and provides better neuroprotection.