The Effects of Added Sugar Intake on Brain Blood Flow and Hippocampal Function in Midlife Adults

NCT ID: NCT05211726

Last Updated: 2025-06-12

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 44 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-01-11
• Study Completion Date: 2024-05-03

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.

Conditions

Aging; Healthy Diet

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: HEALTH_SERVICES_RESEARCH
• Blinding Strategy: SINGLE

Study Groups

Low Added Sugar Diet

Subjects will be provided with a diet that is low in added sugars.

Group Type: EXPERIMENTAL

Low Added Sugar Diet

Intervention Type: OTHER

Consumption of 10 days of a diet low in added sugars (5% of total caloric intake)

High Added Sugar Diet

Subjects will be provided with a diet that is high in added sugars.

Group Type: EXPERIMENTAL

High Added Sugar Diet

Intervention Type: OTHER

Consumption of 10 days of a diet high in added sugars (25% of total caloric intake)

Interventions

Low Added Sugar Diet

Consumption of 10 days of a diet low in added sugars (5% of total caloric intake)

Intervention Type: OTHER

High Added Sugar Diet

Consumption of 10 days of a diet high in added sugars (25% of total caloric intake)

Intervention Type: OTHER

Eligibility Criteria

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.

• Minimum Eligible Age: 50 Years
• Maximum Eligible Age: 64 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

National Institute of General Medical Sciences (NIGMS)

NIH

Sponsor Role: collaborator

University of Delaware

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Christopher Martens, Ph.D.

Role: PRINCIPAL_INVESTIGATOR

University of Delaware

Locations

University of Delaware

Newark, Delaware, United States

Countries

United States

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

P20GM113125

Identifier Type: NIH

Identifier Source: secondary_id

View Link

1760500

Identifier Type: -

Identifier Source: org_study_id