Investigate the Effect of Tart Montmorency Cherry Juice (Prunus Cerasus) on Cerebral Blood Flow and Cognitive Function
Condition: Cognitive Decline
MeSH terms: Cognitive Dysfunction
Study type: Interventional

Summary: 
      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
    

Detailed description: 
      Each participant will be required to attend the laboratory on three occasions. The first of
      these will be an initial screening/training visit, within 14 days of the first active study
      visit. During the initial visit participants will be provided with written informed consent
      and screened with regards the study exclusion/inclusion criteria. Training will be given on
      the cognitive tasks and familiarisation with the study procedures will be provided.

      Study days: Forty - eight hours prior to each study day, participants will begin dietary
      restrictions. Participants will then attend the first study day following an overnight fast.
      A cannula will be inserted and baseline blood samples obtained, baseline measures of cerebral
      blood flow will be examined using near infrared spectroscopy and its effect on cognitive
      function using a cognitive demand battery. The relevant drink will then be provided and blood
      samples and blood flow measures will be taken at hourly intervals (1, 2, 3, and 5h). No
      additional food or drink will be provided during the study period except for low-nitrate
      mineral water. After a minimum of 2 weeks, participants will be asked to return to the lab
      and repeat the procedure with the other drink.

      Cerebrovascular Responses

      Cerebral oxygenation will be assessed using near - infrared spectroscopy . Two near-infrared
      sensors will be placed on the skin over the right and left prefrontal cortex region of the
      forehead, and the signals were averaged to determine cerebral oxygenation. The sensors will
      be secured to the skin using double-sided adhesive tape and shielded from ambient light using
      an elastic bandage. The sensors alternately emit near-infrared light at wavelengths of 730
      and 810 nm. Each sensor contains two detectors located at 3 and 4 cm from the emitting source
      that detect oxygenated and deoxygenated states of Hb to estimate regional O2 saturation based
      on internal algorithms (Rasmussen et al. 2007).

      Blood velocity in the middle cerebral artery (MCAV) will be determined using transcranial
      Doppler sonography. A 2 MHz Doppler probe was positioned over the right middle cerebral
      artery using previously described search techniques (Aaslid et al. 1982) and will be secured
      with an adjustable headset (DiaMon, Compumedics DWL). The mean depth for Doppler signals was
      51 ± 3 mm. Arterial blood pressure will be recorded with a transducer located at heart level
      (TruWave, Edwards Lifesciences, Nyon, Switzerland).
    

Intervention name(s): Placebo; 60mL tart Montmorency cherry juice
Intervention type(s): Other; Dietary Supplement
Intervention description(s): One bolus of less than 5% fruit cordial mixed with water, maltodextrin and whey protein isolate to match for carbohydrate and calorie content of the juice.; One bolus of 60mL of tart Montmorency concentrate mixed with 100mL of water.
Other intervention name(s): less than 5% "Kia Ora" mixed fruit squash
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Prevention