dietary flavanols and dentate gyrus function

Conditions: Memory Loss

Summary: to assess the effect of differing amounts of a cocoa-derived dietary flavanol (epicatechin ) on dentate gyrus function and corresponding cognitive function

in this double blinded trial, the participants, age 50-75 years, will be randomized to receive 0, 260, 510, or 770 mg daily\* for 12 weeks and will be tested before and after the intervention. cognitive testing will be conducted prior to randomization, and at weeks 4, 12, and 20 of the study. in an optional substudy, fmri (functional magnetic resonance imaging) with gadolinium contrast will be conducted to measure dentate gyrus function before randomization and then after completion of the 12-week intervention portion of the trial. \*see note in record log regarding the change in the method of assessment of cocoa flavanol content of the capsules

Eligibility criteria:
inclusion criteria: * 1. signed and dated informed consent obtained before any trial-related activities. (trial-related activities are any procedure that would not have been performed during normal management of the subject). telephone screen 2. healthy male or female subjects. (females must be post-menopausal) telephone screen 3. age between 50 and 75 years, both inclusive. telephone screen 4. body mass index between 18.0 and 35 kg/m², both inclusive. telephone screen exclusion criteria: 1. currently undergoing medical treatment, including prescription drugs/medication. medical history interview 2. clinically significant abnormal hematology, biochemistry, urinalysis, or coagulation screening tests, as judged by the investigator. medical history interview 3. history or presence of cancer (except basal cell skin cancer or squamous cell skin cancer), or any clinically significant cardiovascular, respiratory, metabolic, renal, hepatic, gastrointestinal, endocrinological (with the exception euthyroid struma), haematological, dermatological, venereal, neurological, psychiatric diseases or other major disorders as judged by the investigator. medical history interview 4. seated blood pressure at screening (after resting for 5 min in seated position) outside the range of 90-140 mmhg for systolic or 50-90 mmhg for diastolic (excluding white-coat hypertension; therefore, if a repeated measurement shows values within the range, the subject can be included in the trial) and/or resting supine heart rate outside the range 50-90 beats per minute. measurement taken at consent before eligibility is determined 5. current depression or anxiety symptoms using phq-8 (eight-item patient health questionnaire depression scale) and gad-7 (generalized anxiety disorder 7-item scale). phq-8 score \>= 10 and/or gad-7 score \>= 10 are excluded. (past history of disorders not exclusionary). interview 6. currently taking ssri (selective serotonin reuptake inhibitor) medications for any reason. interview 7. heart diseases. medical history interview 8. hepatitis b or c positive status. medical history interview 9. hiv positive status. medical history interview 10. history of multiple and/or severe allergies to drugs or foods or a history of severe anaphylactic reaction. medical history interview 11. use of non-prescription medication, herbal products or nutritional supplements during the study, and within the last 4 weeks before the start of the study (screening), as judged by the investigator; occasional use of aspirin, ibuprofen, acetaminophen is permitted. interview 12. adherence to a vegan or vegetarian diet or to specialty/uncommon diets. interview 13. food allergies to tree nuts, soy, cocoa and cocoa-containing products. interview 14. people who choose to avoid caffeine intake. interview 15. current or history of alcoholism or drug/chemical abuse as per investigator's judgment. medical history interview 16. hormone replacement therapy; currently pregnant; pregnant or lactating within past 6 mos; hormonal birth control (pill). interview 17. smoking. interview 18. unwilling to have blood drawn or anxiety/nausea during a blood draw. interview. 19. uncomfortable completing memory and attention tasks in the english language. interview 20. moca (montreal cognitive assessment) score less than 26. montreal cognitive assessment 21. inability to swallow study capsules. interview (at consent). 22. did not complete the two weeks run-in period (participants who missed more than 2 intake occasions out of 14 days (28 occasions total) or if there are \> 8 capsules left in the bottle after the two weeks will be excluded). run-in period. mri related 1. cardiac pacemaker interview 2. internal pump interview 3. insulin pump interview 4. tattoo eyeliner interview 5. wire sutures interview 6. internal metal objects interview 7. metal slivers in eye interview 8. prosthesis interview 9. hearing aid implants interview 10. neurostimulator interview 11. metal fragments interview 12. brain aneurysm clips interview 13. vascular clips interview 14. breast expander interview 15. vena cava filter interview 16. heart valve interview 17. metal stents interview 18. asthma interview 19. hay-fever interview 20. sickle cell disease interview 21. kidney disease interview 22. pregnant interview 23. claustrophobic interview 24. wheelchair bound interview 25. machinist or ever worked with heavy metals interview 26. contraindication to gadolinium, including prior adverse reaction to gadolinium, past or current history of severe breathing difficulty that has been treated by a physician (e.g. asthma, copd (chronic obstructive pulmonary disease), etc) and sickle cell disease. history of renal impairment or estimated glomerular filtration rate \<30 l/min.1.732m2 is also exclusionary interview; glomerular filtration rate assessed with creatinine via statsensor monitor 27. had more than one previous mri scans with gadolinium interview