Hypertension (HTN), or high blood pressure (BP) is a major modifiable risk factor for
heart disease, the leading cause of death worldwide. In the U.S., 121.5 million adults
have high BP and only 25% have their BP under control. The 2022 Heart Disease and Stroke
Statistics indicated that the incidence of high BP was higher among non-Hispanic Black
(NHB) compared to non-Hispanic White (NHW) adults. Berries are rich in fiber and
phytochemicals and have several health benefits. A 14-year follow-up of the Nurses'
Health Study I and II and the Health Professional Follow-Up Study revealed a significant
reduction in the risk of HTN (8%) among individuals in the highest quintile of
anthocyanin intake compared to the lowest quintile. Blueberries are rich in fiber and
phytochemicals that may be responsible for their health benefits. Studies have shown that
daily blueberry consumption improves heart, cognitive, and intestinal health in different
populations. Yet, a comprehensive study exploring and comparing the effectiveness of wild
blueberries for cardiovascular, intestinal, and cognitive function parameters and their
association in NHB and NHW adults with high BP has not been conducted to date.
Thus, the overall objective of this timely study is to determine and compare the
effectiveness of a freeze-dried wild blueberry intervention on cardiovascular and gut
health in NHB and NHW adults with high BP and assess whether these health benefits are
associated with improvements in memory and other important thinking abilities for
productivity and quality of life.
Therefore, this 8-week randomized, placebo-controlled parallel-arm clinical trial aims to
assess whether daily consumption of 22 g of freeze-dried wild blueberry powder improves
gut, cardiovascular, and cognitive function in NHB and NHW adults with elevated blood
pressure and stage 1 hypertension. Investigators hypothesize that daily consumption of
wild blueberries will improve cardiovascular parameters, gut dysbiosis, and cognitive
function. To test these hypotheses, the following specific aims are proposed. To
investigate whether daily consumption of 22 g of freeze-dried wild blueberry powder:
Reduces BP, improves endothelial function, arterial stiffness, and microcirculation.
Favorably modulates gut microbiota composition.
Improves cognitive function (verbal memory and executive functions [inhibition,
working memory, cognitive flexibility]).
Improves serum markers of oxidative stress and inflammation.
Additionally, investigators will also explore 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 globally and within each race.