 Scientific studies in humans suggest that diets high in fruit and vegetables may be able to improve some aspects of mental performance such as improving memory and reaction times. One reason that that these improvements may occur is that these compounds contain phytochemicals which may increase blood flow and, therefore, the delivery of oxygen and nutrients to the brain. If this is the case it is possible to measure this increased blood flow by a non-invasive technique called Near Infrared Spectroscopy. The purpose of this study is to examine the effect of a fruit juice on cerebral blood flow and cognitive function 