Blood Pressure, Orthostatic Hypotension, Vascular Diseases
Conditions
Keywords
Blueberries, Dates, Older Adults, Blood pressure, Fruit, Vascular health, Dietitian
Brief summary
This randomized, parallel-design trial will evaluate specific clinical and physiological effects of whole blueberries in adults 70 years of age or older.
Detailed description
Although much is already known about the benefits of a healthy diet for the prevention of a wide range of chronic diseases, including the particular health benefits of anthocyanin-rich foods, these effects have been examined with much less frequency in older adults, who tend to be excluded from formal feeding studies and, until recently, have represented a small proportion of ongoing cohort studies. The proposed study will randomize approximately 46 women and 24 men, representative of the proportion of elderly women and men in the U.S. to consume either: 1. 1 cup of frozen blueberries daily for 12 weeks or 2. 2-3 dried dates daily for 12 weeks. Dates were chosen as a control food because they contain negligible polyphenols, proportionately high caloric content, and a convenient form for storage. After the 12-week intervention, researchers will repeat in-person study assessments from baseline.
Interventions
BEHAVIORALBlueberry Consumption
Participants will consume 1 cup of frozen blueberries daily for the 12 weeks of the intervention. The study dietitian will provide educational materials and monitor compliance through weekly check-ins. Participants will be instructed to avoid all other high-anthocyanin foods including other berries, cherries, currants, cabbage, red wine, and eggplant.
BEHAVIORALDried Date Consumption
Participants will consume 2-3 dried dates daily for the 12 weeks of the intervention, an isocaloric portion of fruit compared to the blueberry group. The study dietitian will provide educational materials and monitor compliance through weekly check-ins. Participants will be instructed to avoid all other high-anthocyanin foods including blueberries, other berries, cherries, currants, cabbage, red wine, and eggplant.
Sponsors
U.S. Highbush Blueberry Council
Beth Israel Deaconess Medical Center
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Outcomes Assessor)
Intervention model description
Individual, parallel-design, randomized trial
Eligibility
Sex/Gender
ALL
Age
70 Years to 100 Years
Healthy volunteers
Yes
Inclusion criteria
* 70 years old * Independent-living
Exclusion criteria
* Cardiovascular event or procedure within 3 months of randomization * AHA Class III-IV heart failure * Intolerance or allergy to blueberries or dates * History of gastric bypass surgery * Any planned hospitalization or vacation in the ensuing 4 months * Any current cancer treatment * End-stage renal disease * Any organ transplant * Uncontrolled diabetes mellitus with hemoglobin A1c \>9% * Systolic blood pressure \>200 mmHg * Inability to provide personal informed consent (e.g. cognitive impairment) * Investigator concern
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Ambulatory Blood Pressure Monitoring | 12 weeks after randomization | 24-hour wake-time ambulatory blood pressure monitoring |
| Orthostatic Hypotension | 12-weeks after randomization | Supine and standing blood pressure |
| Lower Extremity Functioning | 12 weeks after randomization | Short Physical Performance Battery |
| Cognition | 12 weeks after randomization | Cogstate Brief Battery of four core cognitive domains: processing speed, attention, visual learning, and working memory |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Immune System Diversity | 12 weeks after randomization | Measure in blood samples to show diversity of immune sequences |
| Fructosamine | 12 weeks after randomization | Measured in blood to estimate glucose levels over the previous 2-3 weeks. |
| Free Fatty Acids | 12 weeks after randomization | Measured in blood samples |
| C-Reactive Protein (CRP) | 12 weeks after randomization | Measured concentration in blood in response to inflammation |
| C-terminal telopeptide of type 1 collagen | 12 weeks after randomization | Measured in blood samples to assess bone turnover |
| T-Cell Receptor Portfolio | 12 weeks after randomization | Adaptive Immune Receptor Repertoire sequences in blood samples |
| Number of Self-Reported Falls | Weekly for 12 weeks between baseline and follow-up | Investigators will administer the Fall Follow-Up Questionnaire from the Study to Understand Fall Reduction and Vitamin D in You (STURDY) to participants that self-report falls to record details on each fall. |
| Grip Strength | 12 weeks after randomization | Bilateral grip strength measured by a dynamometer |
| Sleep | 12 weeks after randomization | Pittsburgh Sleep Quality Index. The 19 self-rated items are combined to form 7 component scores, each of which has a range of 0-3 points. In all cases, a score of 0 indicates no difficulty, while a score of 3 indicates severe difficulty. The 7 component scores are then added to yield one global score, with a range of 0-21 points, 0 indicating no difficulty and 21 indicated severe difficulties in all sleep areas. |
| Incontinence | 12 weeks after randomization | Questionnaire for Urinary Incontinence Diagnosis. The first 3 items focus on stress incontinence symptoms and the last 3 on urge incontinence symptoms. Each item includes 6 frequency-based response options, which are scored from 0 to 5 points. Scores are calculated in an additive fashion, resulting in separate Stress and Urge score, each ranging from 0-15 points. Higher scores indicate more severe incontinence symptoms. |
| Cardiac Ectopy | 12 weeks after randomization | Number of participants with atrial premature beats detected by a 24-hour Holter monitor |
| Troponin T (HS) | 12 weeks after randomization | Measured in blood sample |
| High Density Lipoprotein Cholesterol | 12 weeks after randomization | Measured in fasted blood as part of a lipid panel |
| Total Cholesterol | 12 weeks after randomization | Measured in fasted blood as part of a lipid panel |
| Derived Low Density Lipoprotein Cholesterol | 12 weeks after randomization | Measured in fasted blood as part of a lipid panel |
| Triglycerides | 12 weeks after randomization | Measured in fasted blood as part of a lipid panel |
| Estimated Glomerular Filtration Rate (eGFR) | 12 weeks after randomization | Measured in blood as part of basic metabolic panel |
| Albumin-to-Creatinine Ratio | 12 weeks after randomization | Measured in a spot urine sample to detect albuminuria |
Other
| Measure | Time frame | Description |
|---|---|---|
| Total and Direct Bilirubin | 12 weeks after randomization | Measured in blood samples |
| Fasting Glucose | 12 weeks after randomization | Measured in blood samples |
| Fasting Insulin | 12 weeks after randomization | Measured in blood samples |
| White Blood Cell Count | 12 weeks after randomization | Measured in blood samples as part of complete blood count |
| Liver Enzymes | 12 weeks after randomization | Measuring AST and ALT in blood samples |
Countries
United States
Outcome results
None listed