Aging, Healthy Diet
Conditions
Keywords
added sugars, arterial stiffness, cerebrovascular function, cognitive function
Brief summary
This study will focus on improving brain health through dietary modification of added sugars in middle aged adults (50- 64 years old). Participants will be fed two 10-day diets (one diet containing 5% of total energy from added sugars and one diet containing 25% of total energy from added sugars) and examine blood vessel function, hippocampus structure using a MRI, and memory performance.
Detailed description
Aging is the primary risk factor for Alzheimer's disease (AD) which is the most common form of dementia and among the fastest growing causes of morbidity and mortality in the United States. The risk factors for AD emerge during midlife and are similar to cardiovascular and cerebrovascular diseases. The impact of midlife peripheral vascular changes on cardiovascular risk are worsened by poor lifestyle habits, including eating a diet that contains a lot of added sugars (defined as all caloric sweeteners added to food during processing or preparation). One effect of eating a high added sugar diet is an elevation in blood triglycerides (TGs), which impairs blood vessel function by causing inflammation; however, it is not known whether eating a lot of added sugars affects the blood vessels in the brain. The purpose of this project is to determine if there is a link between added sugar intake and brain health in midlife adults. Our hypothesis is that eating excess added sugar impairs the structure and function of an area of the brain called the hippocampus by increasing plasma TGs and systemic inflammation. To test this, we will have people eat a high and low sugar diet for 10 days each (in a random order) and test how each diet affects their blood vessel function, the structure of their hippocampus, and their memory performance. We expect to show that eating a diet that contains a lot of added sugars worsens brain health compared to a diet that contains few added sugars. The data generated from this project will help us better understand risk factors for dementia and will be used to support a future grant proposal to the National Institutes of Health aimed at lowering added sugar intake in mid-life adults and individuals with mild cognitive impairment.
Interventions
OTHERLow Added Sugar Diet
Consumption of 10 days of a diet low in added sugars (5% of total caloric intake)
Consumption of 10 days of a diet high in added sugars (25% of total caloric intake)
Sponsors
National Institute of General Medical Sciences (NIGMS)
University of Delaware
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
SINGLE (Investigator)
Intervention model description
A single-blind, randomized-crossover, controlled feeding study. Participants will be provided with 10-days each of a research diet containing low sugar (LS; 5% of energy from added sugars) vs. high sugar (HS; 25% of energy from added sugars) in a random order, separated by a 2-week washout.
Eligibility
Sex/Gender
ALL
Age
50 Years to 64 Years
Healthy volunteers
Yes
Inclusion criteria
* ability to provide informed consent; * men and postmenopausal women aged 50-64 years; * habitual intake of added sugars ≤15% of total calories; * systolic BP \< 130 mmHg; diastolic BP \< 90 mmHg; * body mass index (BMI) \<30 kg/m2 and % body fat \< 25% for men and \< 33% for women; * fasting triglycerides \< 200 mg/dl (\< 2.3 mmol/L); * LDL cholesterol \<160 mg/dl (4.14 mmol/L); * fasting plasma glucose \<126 mg/dl (\<7.0 mmol/L) and hemoglobin A1C \< 6.5% at screening; * weight stable in the prior 6 months (≤ 2 kg weight change); * blood chemistries indicative of normal liver enzymes and renal function (estimated glomerular filtration rate using the Modification of Diet in Renal Disease (MDRD) prediction equation must be \>60 ml/min/1.73 m\^2).
Exclusion criteria
* current use of medications or supplements known to lower blood triglycerides or cholesterol (e.g., fibrates, statins, high dose niacin, high dose omega-3 supplement); * chronic clinical diseases (e.g., coronary artery/peripheral artery/cerebrovascular diseases, heart failure, diabetes, chronic kidney disease requiring dialysis, neurological or autoimmune conditions affecting cognition (e.g. Alzheimer's disease or other form of dementia, Parkinson's disease, epilepsy, multiple sclerosis, large vessel infarct); * major psychiatric disorder (e.g. schizophrenia, bipolar disorder); * major depressive disorder (PHQ-9 ≥ 10); * current or past (i.e., last 3 months) use of anti-hypertensive or other cardiovascular-acting medications known to influence vascular function and/or arterial stiffness; * current medication use likely to affect central nervous system (CNS) functions (e.g. long active benzodiazepines); * concussion within last 2 years and ≥ 3 lifetime concussions; * heavy alcohol consumption (defined by the Centers for Disease Control and Prevention and United States Department of Agriculture as ≥8 drinks/week for women and ≥15 drinks/week for men). * claustrophobia, metal implants, pacemaker or other factors affecting feasibility and/or safety of MRI scanning; * recent major change in health status within previous 6 months (i.e., surgery, significant infection or illness); * current smoking within the past 3 months; * High degree of physical activity as defined by ≥ 25 leisure metabolic equivalent (MET)-hours/week, within the past 3 months.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Seated Diastolic Blood Pressure (mmHg) | Day 10 of diet | Seated diastolic blood pressure taken with arm at heart level after a 10-minute rest. Results are average of triplicate measurements |
| Arterial Compliance (m^2 Kilopascal^-1) | Day 10 of the diet | Change in cross-sectional area of the common carotid artery (assessed using ultrasound) per 1 mmHg increase in carotid artery blood pressure (assessed by applanation tonometry). A lower carotid artery compliance is indicative of stiffer elastic arteries. |
| Cerebrovascular Reactivity (Percent Increase in Cerebral Perfusion Normalized to the Increase in PETCO2 | Day 10 of the diet | Cerebrovascular reactivity (CVR) is the relative (percent) change in total cerebral perfusion measured using pseudo-continuous arterial spin labeling per mmHg change in end-tidal carbon dioxide (ETCO2) during a brief period of hypercapnia. Hypercapnia was induced by prospective end-tidal targeting (RespirAct, Thornhill Medical) in which a target change in end-tidal CO2 of +9 millimeters of mercury (mmHg) was set. Data were only analyzed if ETCO2 changed by at least 6.5 mmHg. All data were then normalized to the absolute change in ETCO2. |
| Hippocampal Stiffness (kPa) | Day 10 of the diet | Noninvasive brain imaging using Magnetic Resonance Elastography (MRE) to estimate tissue mechanical properties. Stiffness values are derived from the propagation of shear waves delivered to the head using vibration at 50 Hertz (Hz) from an acoustic driver system (Resoundant, Inc, Rochester MN) and reflects the distribution and organization of neurons, axons, and glial cells. A higher brain stiffness indicates greater tissue integrity. A nonlinear inversion algorithm estimated mechanical properties in the brain from acquired MRE displacement data to map shear modulus, G = G'+iG, where G' is the storage modulus and G'' is the loss modulus. From these parameters, stiffness is calculated, μ = 2\*\|G\|\^2 / (\|G\|+G') |
| Hippocampal Damping Ratio (Unitless Ratio) | Day 10 of the diet | Noninvasive brain imaging using Magnetic Resonance Elastography (MRE) to estimate tissue mechanical properties. Damping Ratio is derived from the propagation of shear waves delivered to the head using vibration at 50Hz from an acoustic driver system (Resoundant, Inc, Rochester MN) and reflects the relative elasticity of the brain tissue. A lower damping ratio indicates greater tissue integrity. A nonlinear inversion algorithm estimated mechanical properties in the brain from acquired MRE displacement data to map shear modulus, G = G'+iG, where G' is the storage modulus and G'' is the loss modulus. From these parameters, damping ratio is calculated, ξ = G/2\*G' |
| Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Day 10 of the diet | The Revised Hopkins Verbal Learning Test (HVLT-R) assesses verbal learning and memory, immediate recall and delayed recall from a list of 12 words. Immediate recall takes place over 3 trials (out of 12 correct responses each) Total recall is the sum of trials 1-3 (out of 36 correct responses). Delayed recall takes place 20-25 minutes after trial 3 and the participant must recall the entire list of words (out of 12 correct responses). |
| Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Day 10 of the diet | The Revised Brief Visuospatial Memory Test (BVMT-R) assesses visuospatial memory and includes an immediate recall and delayed recall from images. Immediate recall takes place over 3 trials (out of 12 correct responses each) Total recall is the sum of trials 1-3 (out of 36 correct responses). Delayed recall takes place 20-25 minutes after trial 3 and the participant must recall or redraw all the images (out of 12 correct responses). |
| Seated Systolic Blood Pressure (mmHg) | Day 10 of diet | Seated systolic blood pressure taken with arm at heart level after a 10-minute rest. Results are average of triplicate measurements |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Pattern Comparison Processing Speed Test (Raw/Computed Score) | Day 10 of the diet | National Institute of Health (NIH) Toolbox Pattern Comparison Processing Speed Test Brief, computer-based assessment of processing speed in which participants quickly determine if two visual patterns are the same or different. For age 50-59, raw/computed score has a mean of 41.53 and standard deviation of 19.42 based on a normative dataset (Range = 11.00 - 65.00). For age 60-69, raw/computed score has a mean of 39.44 and standard deviation of 16.39 based on a normative dataset (Range = 7.00 - 64.00). A higher score indicates a better outcome. |
| Carotid-femoral Pulse Wave Velocity (CFPWV) (m/Seconds) | Day 10 of the diet | Carotid-femoral pulse wave velocity (CFPWV) assessed using applanation tonometry of the carotid artery and cuff-based assessment of the femoral pulse wave (SphygmoCor XCEL). CFPWV is calculated as the distance between the carotid and femoral pulse divided by the time-delay between pulses. A higher CFPWV is indicative of stiffer elastic arteries. |
| Flanker Test (Raw/Computed Score) | Day 10 of the diet | Brief, standardized assessment of attention and inhibitory control, which are key components of executive function. For age 50-59, raw/computed score has a mean of 8.21 and standard deviation of 1.73 based on a normative dataset (Range = 3.88 - 9.74). For age 60-69, raw/computed score has a mean of 8.16 and standard deviation of 1.60 based on a normative dataset (Range = 3.63 - 9.59). A higher score indicates a better outcome. |
| Triglycerides (mg/dL) | Day 10 of the diet | Blood biomarkers triglycerides in mg/dL |
Other
| Measure | Time frame | Description |
|---|---|---|
| Oxidative Stress | Day 10 of the diet | Blood biomarkers of oxidative stress (e.g. superoxide) using Electron Paramagnetic Resonance |
| Inflammatory Cytokines (%) | Day 10 of the diet | Biomarkers of inflammation (e.g. cytokines) from peripheral blood mononuclear cells |
| Sleep Quality (%) | Day 10 of the diet | Sleep quality will be continuously measured for 10 days using an Actiwatch. |
Countries
United States
Participant flow
Recruitment details
Participants were screened for inclusion in this study at the University of Delaware between January 11, 2022 - January 5, 2024. The study concluded on May 3, 2024.
Pre-assignment details
44 participants were consented and randomized. After baseline testing, but prior to starting the intervention, 5 participants withdrew \[MRI concerns (N=3) or unable to maintain the required time commitment (N=2)\]. 1 participant started the intervention, but was dropped due to a change in medication not-related to the study, thus making this participant ineligible. A total of 38 participants completed both the high and low sugar diet, with a ≥ 2-week washout in between.
Participants by arm
| Arm | Count |
|---|---|
| Low Sugar, High Sugar Diet Subjects will be provided with a diet that is low in added sugars followed by a diet that is high in added sugars.
1. Low Added Sugar Diet: Consumption of 10 days of a diet low in added sugars (5% of total caloric intake)
2. High Added Sugar Diet: Consumption of 10 days of a diet high in added sugars (25% of total caloric intake) | 18 |
| High Sugar, Low Sugar Diet Subjects will be provided with a diet that is high in added sugars followed by a diet that is low in added sugars.
1. High Added Sugar Diet: Consumption of 10 days of a diet high in added sugars (25% of total caloric intake)
2. Low Added Sugar Diet: Consumption of 10 days of a diet low in added sugars (5% of total caloric intake) | 20 |
| Total | 38 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Protocol Violation | 0 | 1 |
| Overall Study | Withdrawal by Subject | 2 | 3 |
Baseline characteristics
| Characteristic | High Sugar, Low Sugar Diet | Low Sugar, High Sugar Diet | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 20 Participants | 18 Participants | 38 Participants |
| Age, Continuous | 57 years STANDARD_DEVIATION 4 | 57 years STANDARD_DEVIATION 4 | 57 years STANDARD_DEVIATION 4 |
| Body mass index (BMI) | 24.4 kg/m^2 STANDARD_DEVIATION 3.1 | 26.0 kg/m^2 STANDARD_DEVIATION 3.4 | 25.2 kg/m^2 STANDARD_DEVIATION 3.3 |
| Body mass (kg) | 71.2 kg STANDARD_DEVIATION 11.4 | 77.1 kg STANDARD_DEVIATION 16.4 | 74.0 kg STANDARD_DEVIATION 14.2 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 20 Participants | 18 Participants | 38 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Height (cm) | 170.5 cm STANDARD_DEVIATION 8 | 171.4 cm STANDARD_DEVIATION 10.6 | 170.9 cm STANDARD_DEVIATION 9.2 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants | 0 Participants | 1 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 18 Participants | 16 Participants | 34 Participants |
| Region of Enrollment United States | 20 Participants | 18 Participants | 38 Participants |
| Seat diastolic blood pressure (mmHg) | 70 mmHg STANDARD_DEVIATION 7 | 70 mmHg STANDARD_DEVIATION 8 | 70 mmHg STANDARD_DEVIATION 7 |
| Seated systolic blood pressure (mmHg) | 113 mmHg STANDARD_DEVIATION 10 | 116 mmHg STANDARD_DEVIATION 9 | 114 mmHg STANDARD_DEVIATION 10 |
| Sex: Female, Male Female | 13 Participants | 11 Participants | 24 Participants |
| Sex: Female, Male Male | 7 Participants | 7 Participants | 14 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 38 | 0 / 38 |
| other Total, other adverse events | 0 / 38 | 0 / 38 |
| serious Total, serious adverse events | 0 / 38 | 0 / 38 |
Outcome results
Primary
Arterial Compliance (m^2 Kilopascal^-1)
Change in cross-sectional area of the common carotid artery (assessed using ultrasound) per 1 mmHg increase in carotid artery blood pressure (assessed by applanation tonometry). A lower carotid artery compliance is indicative of stiffer elastic arteries.
Time frame: Day 10 of the diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Arterial Compliance (m^2 Kilopascal^-1) | 0.824 m^2 kilopascal^-1 | Standard Deviation 0.28 |
| Low Sugar Diet | Arterial Compliance (m^2 Kilopascal^-1) | 0.772 m^2 kilopascal^-1 | Standard Deviation 0.201 |
Primary
Cerebrovascular Reactivity (Percent Increase in Cerebral Perfusion Normalized to the Increase in PETCO2
Cerebrovascular reactivity (CVR) is the relative (percent) change in total cerebral perfusion measured using pseudo-continuous arterial spin labeling per mmHg change in end-tidal carbon dioxide (ETCO2) during a brief period of hypercapnia. Hypercapnia was induced by prospective end-tidal targeting (RespirAct, Thornhill Medical) in which a target change in end-tidal CO2 of +9 millimeters of mercury (mmHg) was set. Data were only analyzed if ETCO2 changed by at least 6.5 mmHg. All data were then normalized to the absolute change in ETCO2.
Time frame: Day 10 of the diet
Population: 5 participants did not have a CVR test with a ETCO2 changed by at least 6.5 mmHg.~2 participants did not perform the CVR test (due to discomfortable from the mask or not adequate space in the head coil).~MRI was quenched (not working) for 2 participant during both diets.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Cerebrovascular Reactivity (Percent Increase in Cerebral Perfusion Normalized to the Increase in PETCO2 | 4.035 percent increase in cerebral perfusion n | Standard Deviation 2.486 |
| Low Sugar Diet | Cerebrovascular Reactivity (Percent Increase in Cerebral Perfusion Normalized to the Increase in PETCO2 | 6.075 percent increase in cerebral perfusion n | Standard Deviation 3.789 |
Primary
Hippocampal Damping Ratio (Unitless Ratio)
Noninvasive brain imaging using Magnetic Resonance Elastography (MRE) to estimate tissue mechanical properties. Damping Ratio is derived from the propagation of shear waves delivered to the head using vibration at 50Hz from an acoustic driver system (Resoundant, Inc, Rochester MN) and reflects the relative elasticity of the brain tissue. A lower damping ratio indicates greater tissue integrity. A nonlinear inversion algorithm estimated mechanical properties in the brain from acquired MRE displacement data to map shear modulus, G = G'+iG, where G' is the storage modulus and G'' is the loss modulus. From these parameters, damping ratio is calculated, ξ = G/2\*G'
Time frame: Day 10 of the diet
Population: MRI was quenched (not working) for 2 participant during both diets. The resoundant acoustic driver system did not work for 2 participants during the LS diet.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Hippocampal Damping Ratio (Unitless Ratio) | 0.18186 unitless ratio | Standard Deviation 0.02949 |
| Low Sugar Diet | Hippocampal Damping Ratio (Unitless Ratio) | 0.18794 unitless ratio | Standard Deviation 0.02982 |
Primary
Hippocampal Stiffness (kPa)
Noninvasive brain imaging using Magnetic Resonance Elastography (MRE) to estimate tissue mechanical properties. Stiffness values are derived from the propagation of shear waves delivered to the head using vibration at 50 Hertz (Hz) from an acoustic driver system (Resoundant, Inc, Rochester MN) and reflects the distribution and organization of neurons, axons, and glial cells. A higher brain stiffness indicates greater tissue integrity. A nonlinear inversion algorithm estimated mechanical properties in the brain from acquired MRE displacement data to map shear modulus, G = G'+iG, where G' is the storage modulus and G'' is the loss modulus. From these parameters, stiffness is calculated, μ = 2\*\|G\|\^2 / (\|G\|+G')
Time frame: Day 10 of the diet
Population: MRI was quenched (not working) for 2 participant during both diets. The resoundant acoustic driver system did not work for 2 participants during the Low Sugar Diet.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Hippocampal Stiffness (kPa) | 3.09473 kPa | Standard Deviation 0.29062 |
| Low Sugar Diet | Hippocampal Stiffness (kPa) | 3.04559 kPa | Standard Deviation 0.306 |
Primary
Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score
The Revised Brief Visuospatial Memory Test (BVMT-R) assesses visuospatial memory and includes an immediate recall and delayed recall from images. Immediate recall takes place over 3 trials (out of 12 correct responses each) Total recall is the sum of trials 1-3 (out of 36 correct responses). Delayed recall takes place 20-25 minutes after trial 3 and the participant must recall or redraw all the images (out of 12 correct responses).
Time frame: Day 10 of the diet
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| High Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Trial 2 Recall | 8.0 correct responses | Standard Deviation 2.3 |
| High Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Total Recall | 22.9 correct responses | Standard Deviation 6.3 |
| High Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Trial 3 Recall | 9.3 correct responses | Standard Deviation 2 |
| High Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Delayed Recall | 8.9 correct responses | Standard Deviation 2.1 |
| High Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Trial 1 Recall | 5.6 correct responses | Standard Deviation 2.4 |
| Low Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Delayed Recall | 9.9 correct responses | Standard Deviation 1.8 |
| Low Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Trial 1 Recall | 6.3 correct responses | Standard Deviation 2.1 |
| Low Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Trial 2 Recall | 8.9 correct responses | Standard Deviation 2.2 |
| Low Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Trial 3 Recall | 10.2 correct responses | Standard Deviation 1.8 |
| Low Sugar Diet | Revised Brief Visuospatial Memory Test (BVMT-R) Total Recall Score | Total Recall | 25.2 correct responses | Standard Deviation 5.5 |
Primary
Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory
The Revised Hopkins Verbal Learning Test (HVLT-R) assesses verbal learning and memory, immediate recall and delayed recall from a list of 12 words. Immediate recall takes place over 3 trials (out of 12 correct responses each) Total recall is the sum of trials 1-3 (out of 36 correct responses). Delayed recall takes place 20-25 minutes after trial 3 and the participant must recall the entire list of words (out of 12 correct responses).
Time frame: Day 10 of the diet
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| High Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Trial 2 Recall | 9.7 correct responses | Standard Deviation 1.7 |
| High Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Total Recall | 28.2 correct responses | Standard Deviation 4 |
| High Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Trial 3 Recall | 10.9 correct responses | Standard Deviation 1.3 |
| High Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Delayed Recall | 9.9 correct responses | Standard Deviation 1.9 |
| High Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Trial 1 Recall | 7.6 correct responses | Standard Deviation 1.6 |
| Low Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Delayed Recall | 10.5 correct responses | Standard Deviation 1.7 |
| Low Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Trial 1 Recall | 7.8 correct responses | Standard Deviation 1.8 |
| Low Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Trial 2 Recall | 10.2 correct responses | Standard Deviation 1.5 |
| Low Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Trial 3 Recall | 11.1 correct responses | Standard Deviation 1.2 |
| Low Sugar Diet | Revised Hopkins Verbal Learning Test (HVLT-R) Total Recall Memory | Total Recall | 29.2 correct responses | Standard Deviation 3.9 |
Primary
Seated Diastolic Blood Pressure (mmHg)
Seated diastolic blood pressure taken with arm at heart level after a 10-minute rest. Results are average of triplicate measurements
Time frame: Day 10 of diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Seated Diastolic Blood Pressure (mmHg) | 70 mmHg | Standard Deviation 7 |
| Low Sugar Diet | Seated Diastolic Blood Pressure (mmHg) | 67 mmHg | Standard Deviation 7 |
Primary
Seated Systolic Blood Pressure (mmHg)
Seated systolic blood pressure taken with arm at heart level after a 10-minute rest. Results are average of triplicate measurements
Time frame: Day 10 of diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Seated Systolic Blood Pressure (mmHg) | 115 mmHg | Standard Deviation 10 |
| Low Sugar Diet | Seated Systolic Blood Pressure (mmHg) | 111 mmHg | Standard Deviation 10 |
Secondary
Carotid-femoral Pulse Wave Velocity (CFPWV) (m/Seconds)
Carotid-femoral pulse wave velocity (CFPWV) assessed using applanation tonometry of the carotid artery and cuff-based assessment of the femoral pulse wave (SphygmoCor XCEL). CFPWV is calculated as the distance between the carotid and femoral pulse divided by the time-delay between pulses. A higher CFPWV is indicative of stiffer elastic arteries.
Time frame: Day 10 of the diet
Population: 1 participant did not have an accessible carotid artery via applanation tonometry for both diets
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Carotid-femoral Pulse Wave Velocity (CFPWV) (m/Seconds) | 7.92 m/seconds | Standard Deviation 1 |
| Low Sugar Diet | Carotid-femoral Pulse Wave Velocity (CFPWV) (m/Seconds) | 7.71 m/seconds | Standard Deviation 1.01 |
Secondary
Flanker Test (Raw/Computed Score)
Brief, standardized assessment of attention and inhibitory control, which are key components of executive function. For age 50-59, raw/computed score has a mean of 8.21 and standard deviation of 1.73 based on a normative dataset (Range = 3.88 - 9.74). For age 60-69, raw/computed score has a mean of 8.16 and standard deviation of 1.60 based on a normative dataset (Range = 3.63 - 9.59). A higher score indicates a better outcome.
Time frame: Day 10 of the diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Flanker Test (Raw/Computed Score) | 8.35 score on a scale | Standard Deviation 0.66 |
| Low Sugar Diet | Flanker Test (Raw/Computed Score) | 8.52 score on a scale | Standard Deviation 0.55 |
Secondary
Pattern Comparison Processing Speed Test (Raw/Computed Score)
National Institute of Health (NIH) Toolbox Pattern Comparison Processing Speed Test Brief, computer-based assessment of processing speed in which participants quickly determine if two visual patterns are the same or different. For age 50-59, raw/computed score has a mean of 41.53 and standard deviation of 19.42 based on a normative dataset (Range = 11.00 - 65.00). For age 60-69, raw/computed score has a mean of 39.44 and standard deviation of 16.39 based on a normative dataset (Range = 7.00 - 64.00). A higher score indicates a better outcome.
Time frame: Day 10 of the diet
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Pattern Comparison Processing Speed Test (Raw/Computed Score) | 45.50 score on a scale | Standard Deviation 8.2 |
| Low Sugar Diet | Pattern Comparison Processing Speed Test (Raw/Computed Score) | 47.89 score on a scale | Standard Deviation 6.29 |
Secondary
Triglycerides (mg/dL)
Blood biomarkers triglycerides in mg/dL
Time frame: Day 10 of the diet
Population: 2 participants had missed blood draws on the High Sugar Diet.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| High Sugar Diet | Triglycerides (mg/dL) | 102.9 mg/dL | Standard Deviation 31 |
| Low Sugar Diet | Triglycerides (mg/dL) | 91.2 mg/dL | Standard Deviation 28.3 |
Other Pre-specified
Inflammatory Cytokines (%)
Biomarkers of inflammation (e.g. cytokines) from peripheral blood mononuclear cells
Time frame: Day 10 of the diet
Other Pre-specified
Oxidative Stress
Blood biomarkers of oxidative stress (e.g. superoxide) using Electron Paramagnetic Resonance
Time frame: Day 10 of the diet
Other Pre-specified
Sleep Quality (%)
Sleep quality will be continuously measured for 10 days using an Actiwatch.
Time frame: Day 10 of the diet