In the U.S., 35.3 million adults have type 2 diabetes mellitus (T2DM) and 96 million have
prediabetes. Eight out of 10 people with T2DM die from cardiovascular disease. People
with T2DM also have a 50% higher risk of developing dementia compared to healthy
counterparts. Further, studies show that gut microbes play a major role in the
development of T2DM. Prevention and treatment of T2DM focus on lifestyle changes
including dietary modifications such as increased consumption of deep-colored fruits like
berries. Blueberries are rich in fiber and phytochemicals and have several health
benefits. We and others have shown that blueberry intake improves heart health in healthy
men, hypertensive postmenopausal women, and men and women with metabolic syndrome. Yet, a
comprehensive study in women with prediabetes that measures changes in cognitive
performance and the underlying heart and gut health has not been conducted to date. Thus,
the overall objective of this study is to investigate and bring forth evidence that
blueberries improve gut, cardiometabolic, and cognitive function in women with
prediabetes.
Therefore, this pilot six-week randomized, placebo-controlled parallel-arm clinical trial
aims to investigate whether daily consumption of 22 g of freeze-dried blueberry powder
improves gut, cardiometabolic, and cognitive function in women with prediabetes.
Investigators hypothesize that daily consumption of blueberries will improve
cardiometabolic parameters, gut dysbiosis, and cognitive impairments in our study
population. To test these hypotheses, the following specific aims are proposed. To
investigate whether daily consumption of 22 g of freeze-dried blueberry powder:
Reduces levels of fasting blood glucose (FBG), insulin, and HOMA-IR (homeostatic
model assessment of insulin resistance) and improves lipid profile in women with
prediabetes.
Reduces blood pressure and improves endothelial function in women with prediabetes.
Improves cognitive function (verbal memory and executive functions [inhibition,
working memory, cognitive flexibility]) in women with prediabetes.
Favorably modulates gut microbiota composition in women with prediabetes.
Improves serum markers of oxidative stress and inflammation in women with
prediabetes.
Additionally, whether changes in the gut microbiota are associated with changes in
cardiometabolic and cognitive function outcomes and whether changes in cardiometabolic
outcomes are associated with changes in cognitive function parameters will be explored.