Men who have metabolic syndrome can
help protect their hearts by eating grapes, according to new research published
in the Journal of Nutrition. Researchers found that men who ate grapes reduced
blood pressure, improved blood flow and reduced inflammation. Natural
components found in grapes, known as polyphenols, are thought to be responsible
for these beneficial effects.
The randomized, placebo-controlled,
crossover study conducted at the Department of Nutritional Sciences of the
University of Connecticut, recruited men between 30 and 70 years of age with
metabolic syndrome. The study is believed to be the first to look at the impact
of grapes on metabolic syndrome.
Metabolic syndrome is a cluster of
conditions that occur together – increased blood pressure, a high blood sugar
level, excess body fat around the waist or low HDL (the good cholesterol) and
increased blood triglycerides – significantly increasing the risk for heart
disease, stroke and diabetes. Metabolic syndrome is a major public health
concern, and is on the rise in the United States.
In this study, participants were
randomly assigned to consume grapes, in the form of a freeze-dried whole grape
powder, or a placebo powder, for four weeks. Then, following a 3-week
"washout" period where neither grapes nor placebo were consumed,
individuals were allocated to the alternate treatment. This powerful study
design allowed investigators to compare the response of each individual to
consumption of both the placebo and grapes.
The study results showed that for
each of the study's subjects, grape consumption resulted in significant
decreases in blood pressure, improved blood flow (greater vasodilation), and
decreases in a compound associated with inflammation.
"These results suggest that
consuming grapes can improve important risk factors associated with heart
disease, in a population that is already at higher risk," said principal
investigator Dr. Maria Fernandez. "This further supports the accumulating
evidence that grapes can positively influence heart health, and extends it to
men with metabolic syndrome."