Acute Effect of Pomegranate Extract on Cognitive Function

The double-blinded, randomised, placebo-controlled crossover pilot study is conducted as a two week intervention after a pre-intervention registration and preparation period.

This study explores whether acute supplementation with pomegranate extract can modulate indicators of cognitive function and mood in healthy adults. Changes in physiological and biochemical markers are also investigated.

Participants are asked to visit the QMU clinical lab three times. The first visit is for general information, form completion, measurements and consent plus a practise session on COMPASS, the study computer software. Information and consent forms and a screening questionnaire are completed. Basic information such as age, sex, weight, height and blood pressure data are recorded. Lab visits 2 and 3, which are a week apart, constitute the intervention phase.

Participants are randomly assigned to either the pomegranate extract (PE) or placebo group.The researcher and participants are blinded to which capsules they are taking until data collection is complete. The randomisation process is carried out by independent technical staff who use an internet random number generator site to allocate treatment. The PE and placebo capsules look identical and are placed in sealed, labeled, pre-prepared opaque containers numbered by technicians.

At the next lab session (visit 2) participants begin their randomised study arm, taking either two pomegranate extract or two placebo capsules with water by mouth. Participants repeat the procedure at visit 3, where they crossover to the remaining intervention. Thus if participant A consumed placebo capsules at visit 2, the participant would take pomegranate extract capsules at visit 3, following a washout period of a week. If participant B consumed pomegranate extract on visit 2, the participant would then take the placebo capsules at visit 3.

At each visit, participants complete two computer testing sessions lasting approximately 45 minutes - one pre and one post capsule ingestion. After the capsule is taken there is a one hour absorption period before the next computer test session begins.

Participants are fasted from tea and coffee overnight and abstain for the period of the intervention in the morning. On the day before the tests, they are requested to refrain from alcohol, recreational drugs, and vigorous exercise.

Participants are also required to restrict herbal extracts, food supplements and polyphenols such as dark chocolate, fruit rich in polyphenols and antioxidants to less than three portions for 24 hrs beforehand. A 24 hour pre test food diary is completed to assist in compliance. Participants are also advised to have a good night's sleep - at least 6-8 h during the night before the study day - and should not be more stressed than usual. These aspects are confirmed before participants are allowed to commence their sessions.

Pre-study saliva collection is completed at home by participants early in the morning. This provides a biochemical marker which aims to support both cognitive findings and the results from the Bond Lader mood questionnaire completed during the computer testing. Instructions are given to participants for saliva collection and the samples analysed for cortisol and cortisone. Participants are instructed to have their usual breakfast except for coffee or tea. Blood pressure is taken pre and post study on visits 2 and 3.

The baseline computerised cognitive test battery is administered in the clinic at 9am lasting around 45 mins. The investigator then observes the participants consuming their scheduled capsules. After a one hour quiet absorption period around 11am, blood pressure is taken again. The post cognitive testing battery is completed once more and then a second post study saliva collection is taken. Participants complete the intervention around 12 noon. All assessments are carried out on a QMU computer, with the same laptop used by each participant at baseline and post intervention assessments.

The cognitive testing is conducted under controlled laboratory conditions with the assessments at baseline and post study always performed at the same time of day (between 0830 and 1200) for each participant.

Participant responses to the cognitive tests are recorded automatically by the computer software during the testing battery at visits 2 and 3.

Eligibility Criteria:
Inclusion Criteria:

* Healthy
* Aged 18-65
* Enjoy computer tasks

Exclusion Criteria:

* Diagnosis with any neurological, psychiatric or significant medical condition which could affect cognitive function
* Known cognitive impairment
* Use of any prescription, herbal or recreational drugs
* Gastrointestinal disease
* Pregnancy or breastfeeding
* Pomegranate allergy