Different Types of Fruits on Metabolic Function and Cognitive Performance

The trial is designed as a randomized 2-arm, placebo-controlled, within-subjects crossover utilizing a multiple sampling, repeated measures paradigm to investigate the effects of consumption of different types of fruits on cognitive performance and metabolic responses. This trial will test 2 treatment conditions in forty men and women who will be enrolled into the study. Each subject will be asked to come for one screening visit, a pre-study visit, and two dinner pick-ups the day before each of the two test visits and 2 test visits. Participation in this study will last approximately four weeks. The initial screening visit will provide the subject with the informed consent document and determine eligibility through anthropometric measurements, vital signs, fasting blood glucose test , vein assessment, color test and completion of a survey relate to general eating, health, and exercise habits. In addition, subjects will take brief tests of attention and memory to ensure capability and willingness to perform tests during subsequent research visits. Eligible subjects will be trained and instructed to record all food and beverages consumed for a 3-day period (one weekend day and two weekdays) on food record diaries. At the pre-study visit, subjects will be instructed to follow a strictly limited polyphenolic diet for 7 days prior to the study and throughout their participation time, while maintaining their usual diet pattern and physical activity. A dinner meal will be provided the day before the study visit. At each test visit, subjects will arrive at the clinic after fasting 8 to 12 hours and in a well-hydrated state. After confirming compliance with protocol, anthropometric measurements and vital signs will be taken along with a finger prick for fasting blood glucose and a catheter placement . Fasting baseline blood sample from a catheter will be collected after which baseline cognitive performance measures will be assessed. After completing baseline measures, subjects will receive a standard breakfast meal along with a beverage containing different fruits according to the randomization sequence. Additional blood samples will be taken at 30, 60, 120, 180, 240, 300, 360, and 480 minutes after the start of the breakfast meal. Additional cognitive tests will be performed at the 120, 240, 360, and 480 minute time points. A standardized lunch will be provided between the 360 and 480 minute time points. Subject will come to the clinic for 2 test day visits; all procedures will be the same except for the treatment (the test or control treatment).