Cranberry, already known for its urinary
tract benefits, contains flavonoids (antioxidants) that have been found in
other studies to be associated with lower blood pressure and to reduce risk of
In this randomized controlled
trial, Janet Novotny at the U.S. Department of Agriculture in Beltsville,
Maryland, and her colleagues, measured the blood pressure effects of drinking
low-calorie cranberry juice on 56 healthy non-hypertensive subjects with mean
age of 51 and BMI of 28.4 kg / sqm. The subjects were given two 8-ounce glasses
of low calorie cranberry juice every day for 8 weeks.
Blood pressure was measured and
recorded thrice - on day 1, at 4 weeks, and at the end of the study.
Results showed that blood
pressure dropped from an average of 121/73 mmHg to 118/70 mmHg in the cranberry
juice group but there were no changes in the placebo group.
Both systolic and diastolic blood
pressure fell by an average of 3 mmHg when the trial ended. Most studies 'show
a systolic effect without a diastolic impact when lowering blood pressure'
according to Novotny. In this study, the researchers found that the average
diastolic blood pressure was lower in the cranberry juice group at 69 mmHg
whereas in the placebo group it was 72 mmHg at the end of the treatment.
Cranberry juice is helpful as
long as it does not increase the calorie intake. So the researchers suggested
drinking low-calorie cranberry juice to get maximum benefits.
'If they are trying to reduce
blood pressure through diet, low-calorie cranberry juice would be something
that would be good and healthful to include in the diet' says Novotny.
'We are trying to replace less
healthful fruit juices with more healthful fruit juices. So, we chose cranberry
because of more health benefits including blood pressure', she added.
'Regular calorie cranberry juice
can be quite high in added sugar and high in calories, so I do recommend that
people look for the lower-calorie option in cranberry juice' advised Dr Rachel
Johnson, a professor of nutrition and medicine at the University of Vermont in
Burlington and chair of the American Heart Association's nutrition committee.
This study was published as an
abstract and presented at the American Heart Association's High Blood Pressure
Research 2012 Scientific Sessions. The study is yet to be published in a peer
The study was funded by Ocean Spray Cranberries,
which provided the study drink. Also, one of the co-authors was an employee of
Ocean Spray Cranberries.
1. American Heart Association News Tip - Abstract 299