Could eating blueberries help get rid of belly fat? And could
a blueberry-enriched diet stem the conditions that lead to
diabetes? A new University of Michigan Cardiovascular Center
study suggests so.
The new research, presented April 19 at the Experimental
Biology convention in New Orleans, gives tantalizing clues
to the potential of blueberries in reducing risk factors for
cardiovascular disease and metabolic syndrome. The effect
is thought to be due to the high level of phytochemicals –
naturally occurring antioxidants – that blueberries
The study was performed in laboratory rats. While the animal
findings suggest blueberries may be protective against two
health conditions that affect millions of Americans, more
research should be done.
The researchers studied the effect of blueberries (freeze
dried blueberries crushed into a powder) that were mixed into
the rat diet, as part of either a low- or high-fat diet. They
performed many comparisons between the rats consuming the
test diets and the control rats receiving no blueberry powder.
All the rats were from a research breed that is prone to being
In all, after 90 days, the rats that received the blueberry-enriched
powder, measured as 2 percent of their diet, had less abdominal
fat, lower triglycerides, lower cholesterol, and improved
fasting glucose and insulin sensitivity, which are measures
of how well the body processes glucose for energy.
While regular blueberry intake reduced these risks for cardiovascular
disease and metabolic syndrome, the health benefits were even
better when combined with a low-fat diet.
In addition to all the other health benefits, the group that
consumed a low-fat diet had lower body weight, lower total
fat mass and reduced liver mass, than those who ate a high
fat diet. An enlarged liver is linked to obesity and insulin
resistance, a hallmark of diabetes.
The rats in the study were similar to Americans who suffer
fatty liver disease and metabolic syndrome as a result of
high-fat diets and obesity. Metabolic syndrome is a group
of health problems that include too much fat around the waist,
elevated blood pressure, elevated blood sugar, high triglycerides,
and together these conditions increase the risk of heart attacks,
strokes and diabetes.
But were the health benefits seen in rats a result of losing
abdominal fat, or something else?
“Some measurements were changed by blueberry even if
the rats were on a high fat diet,” says E. Mitchell
Seymour, M.S., lead researcher and manager of the U-M Cardioprotection
Research Laboratory. “We found by looking at fat muscle
tissue, that blueberry intake affected genes related to fat-burning
and storage. Looking at muscle tissue, we saw altered genes
related to glucose uptake.”
Steven Bolling, M.D., a U-M heart surgeon and head of the
Cardioprotection Laboratory, says: “The benefits
of eating fruits and vegetables has been well-researched,
but our findings in regard to blueberries shows the naturally
occurring chemicals they contain, such as anthocyanins, show
promise in mitigating these health conditions.”
Although the current study was supported by the U.S. Highbush
Blueberry Council, which also supplied the blueberry powder,
the council did not play a role in the study’s conduct,
analysis or the preparation of the poster presentation.