Mild Cognitive Impairment
Conditions
Keywords
lutein, avocados, chickpeas, potatoes, elderly
Brief summary
Cognitive impairment is also a major risk factor for development of dementia later in life. Findings from the investigators studies suggest that the carotenoids, lutein and zeaxanthin may be important in cognitive function in the elderly. Avocados are a source of these carotenoids. The investigators study evaluates long-term avocado intervention as a treatment strategy for age-related cognitive impairment which could possibly prevent the onset of dementia. The investigators have also shown that lutein supplementation significantly improved verbal fluency scores in healthy older women. Based on these findings, the next logical step will be to investigate the ability of lutein and zeaxanthin contained in avocados to influence cognitive function in older adults. The investigators hypothesize that there will be a significant increase in cognitive function measures in older adults provided with meals containing 1 avocado/day at the end of 6 months, while no significant improvements will be observed in older adults given daily meals containing chickpeas and/or potatoes. The proposed study is designed as a randomized, placebo controlled trial that tests the effects of 6 month supplementation with 1 avocado/day on cognitive function in older adults. Secondary analyses will determine whether baseline macular pigment (lutein in retina which canbe measured non invasivley) density predicts relative effectiveness of the intervention on cognitive function. Secondary outcomes include plasma biomarkers of oxidative stress and inflammation.
Detailed description
The study is designed as a placebo controlled trial that tests the effects of 6 month supplementation with daily meals containing 1 avocado or isocaloric amounts of chickpeas and/or potatoes on cognitive function in older adults. Subjects will be randomly assigned to one of the two groups. Secondary analyses will determine whether baseline macular pigment density (a non invasive measure of lutein and zeaxanthin in neural tissue) predicts relative effectiveness of the intervention on cognitive function. Secondary outcomes include plasma biomarkers of oxidative stress and inflammation. Participants will be recruited from community-dwelling men and women aged \>50 yr, and potential participants will be screened to meet cognitive and functional criteria. Participants will be pre-screened by telephone; those who appear to meet criteria will undergo further screening. The study will include baseline (0 month), 3 and 6 month visits for study procedures, and monthly telephone calls. Given that there is a visible difference between the two interventions, a blinded study is not possible.
Interventions
OTHERavocado
1 avocado/day for 6 months
OTHERpotato or chickpea
1 cup potatoes or chickpeas/day for 6 months
Sponsors
Tufts University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* men and women age \> 50 years * BMI 19-30 kg/m2 * lutein intake of \< 3 mg/d * Docosahexaenoic acid intake \< 250 mg/d (including supplements) * Mini mental state exam (MMSE) score \> 24 * Macular pigment density \< 0.4 at 0.5 degrees * Beck Depression Inventory \< 20 * free of known disease * BMI 19-29 kg/m2 * must be able to give written informed consent * have normal hematologic parameters * normal values of plasma albumin * normal values for liver and kidney function (Appendix A) * no use of carotenoid, n3 fatty acid, multivitamin/mineral, (\> 2 months).
Exclusion criteria
* history of active small bowel disease or resection * atrophic gastritis * hyperlipidemia (LDL \>120 mg/dL or triglycerides \>150 mg/dL) * hypertension (\>150/90 mm Hg) * diabetes, alcoholism (\>2 drinks/d or 14 drinks/week) * pancreatic disease * anemia, and bleeding disorders (as determined by screening interview) * avocado, potato or chickpea allergy * pregnancy or lactation * diseases that interfere with fat absorption, e.g. colitis, celiac disease, Crohn's disease, cystic fibroids (as determined by screening interview) * medications that interfere with fat absorption, e.g. bile sequestrants (as determined by screening interview) * use of antipsychotic, antimanic, anti-inflammatory, monoamine inhibitors, or dementia medications * smoking or use of nicotine patches or gum (within past 6 months) * use of drugs suspected of interfering with metabolism of blood clotting, e.g. warfarin (as determined by screening interview) * subjects having extremely high dietary intakes of carotenoids as indicated by screening plasma values \> NHANES 95th percentile for lutein/zeaxanthin, beta-carotene, cryptoxanthin, or lycopene * stroke,head injury with loss of consciousness or seizures. * Non English speaking: This is a small study with a sample size. Logistically and financially, getting materials translated for such a small study is not feasible.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Cognition | 6 months | measures of sustained attention will be made using CANTAB, a sensitive computerized program. Signal detection measured on a scale from 0 to 1(bad to good). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Inflammation | 0 months | C-reactive protein |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Chickpeas/Potatoes 1 cup chickpeas/potatoes for 6 months | 20 |
| Avocados 1 avocado/day for 6 months | 20 |
| Total | 40 |
Baseline characteristics
| Characteristic | Chickpeas/Potatoes | Avocados | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 5 Participants | 8 Participants | 13 Participants |
| Age, Categorical Between 18 and 65 years | 15 Participants | 12 Participants | 27 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Black or African American | 4 Participants | 5 Participants | 9 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) White | 14 Participants | 13 Participants | 27 Participants |
| Region of Enrollment United States | 20 participants | 20 participants | 40 participants |
| Sex: Female, Male Female | 11 Participants | 13 Participants | 24 Participants |
| Sex: Female, Male Male | 9 Participants | 7 Participants | 16 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 23 | 0 / 25 |
| other Total, other adverse events | 0 / 23 | 0 / 25 |
| serious Total, serious adverse events | 0 / 23 | 0 / 25 |
Outcome results
Primary
Cognition
measures of sustained attention will be made using CANTAB, a sensitive computerized program. Signal detection measured on a scale from 0 to 1(bad to good).
Time frame: 6 months
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Chickpeas/Potatoes | Cognition | baseline - rapid visual information processing | .90 units on a scale | Standard Deviation 0.05 |
| Chickpeas/Potatoes | Cognition | 3 mo - rapid visual information processing | .92 units on a scale | Standard Deviation 0.05 |
| Chickpeas/Potatoes | Cognition | 6 mo - rapid visual information processing | .92 units on a scale | Standard Deviation 0.05 |
| Avocados | Cognition | baseline - rapid visual information processing | .86 units on a scale | Standard Deviation 0.21 |
| Avocados | Cognition | 3 mo - rapid visual information processing | .92 units on a scale | Standard Deviation 0.04 |
| Avocados | Cognition | 6 mo - rapid visual information processing | .93 units on a scale | Standard Deviation 0.04 |
Secondary
Inflammation
C-reactive protein
Time frame: 0 months
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Chickpeas/Potatoes | Inflammation | 1.3 mg/L | Standard Deviation 1 |
| Avocados | Inflammation | 2.0 mg/L | Standard Deviation 2.8 |
Secondary
Inflammation
C-reactive protein
Time frame: 3 month
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Chickpeas/Potatoes | Inflammation | 2.3 mg/L | Standard Deviation 2.4 |
| Avocados | Inflammation | 2.0 mg/L | Standard Deviation 2.8 |
Secondary
Inflammation
C-reactive protein
Time frame: 6 month
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Chickpeas/Potatoes | Inflammation | 1.6 mg/L | Standard Deviation 1.6 |
| Avocados | Inflammation | 1.7 mg/L | Standard Deviation 1.8 |