Acute Effects of Added Sugar Intake on Cerebrovascular Function and Brain Integrity
Condition: Healthy Diet; Healthy Aging
Study type: Interventional

Summary: 
      This study will focus on acute effects of added sugars on brain health in a specific age
      group (30-64 years old). We will provide participants two meals (one meal containing 16 g of
      added sugars and the other containing 61 g of added sugars) and examine blood vessel function
      and brain structure using a MRI.
    

Detailed description: 
      Cardiometabolic risk factors are strongly influenced by lifestyle-related environmental
      factors including the consumption of an unhealthy Western diet (WD). Added sugars (i.e.,
      caloric sweeteners added to food during processing or preparation) have become a major
      component of the WD that are especially high in added fructose. Americans currently consume
      more calories from added sugars than is recommended by the American Heart Association (AHA),
      leading to an increased risk of cardiovascular disease (CVD), which in turn shares common
      risk factors with age-related memory loss and dementia. Whereas glucose is used as an
      immediate energy source or stored as glycogen, fructose is associated with the delayed
      production of triglycerides (TGs) and uric acid. Previous studies have shown that a single
      high-sugar meal can increase TGs in the blood 150-180 minutes after meal consumption.
      Increased blood TGs promote release of harmful substances that contribute to the reduction in
      blood vessel function and may also impact brain blood vessel function; however, these effects
      are not well established in humans. Our preliminary data has shown a positive association
      between high added sugars and plasma TG and uric acid concentration, which has been
      associated with reduced blood vessel function. However, the direct effects of acute added
      sugar intake on brain blood vessel function is currently unknown. We have also observed that
      high blood TGs are associated with reduced microstructural integrity of the hippocampus, a
      brain structure important for memory and other thinking abilities. Therefore, the purpose of
      this study is to establish a causal link between high added sugar consumption and reduced
      brain blood vessel function and microstructural integrity. We propose to examine the acute
      effects of high TGs and uric acid from a single high-sugar meal on brain blood vessel
      function and brain integrity. To test this hypothesis, we will conduct a
      randomized-controlled crossover trial of a high-sugar meal vs. a low-sugar meal. This project
      has the potential to identify future risk of dementia and other memory-related brain diseases
      caused from repetitive acute insults from high added sugar consumption and will help us
      inform the public to make better dietary choices.
    

Intervention name(s): Low Added Sugar Meal; High Added Sugar Meal
Intervention type(s): Other; Other
Intervention description(s): Consumption of a single 1,250 kcal meal containing 16 g of added sugars (5% of total energy); Consumption of a single 1,250 kcal meal containing 61 g of added sugars (20% of total energy)
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Health Services Research
Keywords: added sugars; brain blood vessel function; brain structure; MRI