The primary objectives are to investigate in older adults the effect of 16-week wild blueberry consumption on (regional) vascular function and insulin-sensitivity in the brain, while we will also focus on changes in cognitive performance as assessed…
ID
Source
Brief title
Condition
- Glucose metabolism disorders (incl diabetes mellitus)
- Cognitive and attention disorders and disturbances
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary endpoint is the difference at follow-up in the cerebral blood flow
response before and after intranasal insulin administration between
interventions.
Secondary outcome
Cognitive performance that will be assessed with a neuropsychological test
battery is the secondary endpoint.
Background summary
Impaired brain vascular function precedes the development of reduced cognitive
performance, while brain insulin-resistance is associated with cognitive
decline. Evidence from epidemiological studies has already suggested beneficial
effects of wild blueberry consumption on cognitive performance. However,
underlying mechanisms have not yet been established, while well-controlled
trials on longer-term effects of wild blueberries on cognitive performance are
highly needed. We hypothesize that longer-term wild blueberry intake improves
(regional) brain vascular function and insulin-sensitivity, thereby improving
cognitive performance in older men and women.
Study objective
The primary objectives are to investigate in older adults the effect of 16-week
wild blueberry consumption on (regional) vascular function and
insulin-sensitivity in the brain, while we will also focus on changes in
cognitive performance as assessed with a neuropsychological test battery (i.e.,
secondary objective). Cerebral blood flow responses before (brain vascular
function) and after the administration of intranasal insulin spray (brain
insulin-sensitivity) will be non-invasively quantified by the non-invasive gold
standard magnetic resonance imaging (MRI)-perfusion method Arterial Spin
Labeling (ASL).
Study design
This intervention study will have a double-blind, randomized, controlled
cross-over design. The total study duration will be 40 weeks, including two
16-week interventions, separated by a wash-out period of at least 8 weeks.
Intervention
Study participants will receive, in a random order, daily 26 g of freeze-dried
wild blueberry powder (wild blueberry intervention) or a matched placebo
(control intervention) for sixteen weeks, separated by a wash-out period of
minimal eight weeks.
Study burden and risks
Subjects will be screened to determine eligibility during one visit of 20
minutes. During these screening visits, anthropometric measurements will be
performed and blood pressure will be determined. In addition, a fasting blood
sample (5.5 mL) will be drawn. During the wild blueberry intervention, adults
will receive daily 26 g of freeze-dried wild blueberry powder for sixteen
weeks. These regimens were well-tolerated in previous trials and are safe, and
there are no expected side effects related to wild blueberry consumption.
During the trial at different occasions, tests will be performed and blood will
be sampled (a total of 425.5 mL during the whole trial). During these tests,
subjects have to stay at the university and are not allowed to eat. Some study
subjects may report pain during venipuncture. Insertion of the cannula can
cause some discomfort and possibly a hematoma or bruise. Some adults may also
report pain during the insertion of the cannula. Arterial Spin Labeling
perfusion MRI non-invasively records cerebral blood flow without any
significant risks. MRI measurements will be performed on a Siemens 3.0 Tesla
Magnetom Prisma Fit scanner. No contrast medication or radioactive tracer
substance will be administered to the participants. Brain insulin-sensitivity
will be assessed by quantifying acute effects of insulin as nasal spray on
cerebral blood flow, which is safe and has already been used in several studies
from our research group before. Other measurements are routine and are not
expected to lead to physical side effects. Participants that not fully adhere
to the study protocol will be excluded from the statistical analyses, because a
per protocol analysis will be performed. The total time investment is 23 hours
(1380 minutes), excluding travel time.
Universiteitssingel 50
Maastricht 6229 ER
NL
Universiteitssingel 50
Maastricht 6229 ER
NL
Listed location countries
Age
Inclusion criteria
- Men and women, aged between 60-75 years
- BMI between 25-35 kg/m2 (overweight or obese)
- Fasting plasma glucose < 7.0 mmol/L
- Fasting serum total cholesterol < 8.0 mmol/L
- Fasting serum triacylglycerol < 4.5 mmol/L
- Systolic blood pressure < 160 mmHg and diastolic blood pressure < 100 mmHg
- Stable body weight (weight gain or loss < 3 kg in the past three months)
- Willingness to give up being a blood donor from 8 weeks before the start of
the study, during the study and for 4 weeks after completion of the study
- No difficult venipuncture as evidenced during the screening visit
Exclusion criteria
- Allergy or intolerance to berries
- Left-handedness
- Current smoker, or smoking cessation < 12 months
- Diabetic patients
- Familial hypercholesterolemia
- Abuse of drugs
- More than 3 alcoholic consumptions per day
- Use of food products or dietary supplements known to interfere with the main
outcomes as judged by the principal investigators
- Use medication to treat blood pressure, lipid, or glucose metabolism
- Use of an investigational product within another biomedical intervention
trial within the previous 1-month
- Severe medical conditions that might interfere with the study, such as
epilepsy, asthma, kidney failure or renal insufficiency, chronic obstructive
pulmonary disease, inflammatory bowel diseases, auto inflammatory diseases, and
rheumatoid arthritis
- Active cardiovascular disease like congestive heart failure or
cardiovascular event, such as an acute myocardial infarction or cerebrovascular
accident
- Contra-indications for MRI imaging (e.g., pacemaker, surgical
clips/material in body, metal splinter in eye, claustrophobia)
Design
Recruitment
Medical products/devices used
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| Other | ClinicalTrials.gov registratie zal plaatsvinden na goedkeuring door METC |
| CCMO | NL87039.068.24 |