Eating Low-Fat Dairy Products Could Lower Blood Pressure, New Research Finds
There may be
an important link between eating low-fat dairy products and better
blood pressure, Harvard Medical School researchers say.
approaches to lowering blood pressure include exercise, weight loss and
the well-known Dietary Approaches to Stop Hypertension (DASH) diet,
which is low in salt and rich in fruits, vegetables and low-fat dairy
products. The DASH diet is also rich in the minerals potassium,
magnesium and calcium, which are found in dairy products.
studies on calcium have had inconsistent results, with several showing
no effect on blood pressure, said Luc Djoussé, M.D., M.P.H.,
D.Sc., lead author of the study and an assistant professor of medicine
at Harvard Medical School in Boston, Mass. The research was reported in
Hypertension: Journal of the American Heart Association.
need to find other dietary factors that could help prevent the
disease,” said Djoussé, who is also an associate
epidemiologist at Brigham and Women’s Hospital in Boston.
He noted that
although low-fat dairy products are considered beneficial, no
conclusive studies explain why. That has caused scientists to wonder
whether dairy’s calcium content or some other unidentified
components provide the apparent benefits.
products, such as cheese, yogurt, and milk, are excellent sources of
calcium,” Djoussé said. “However, some dairy
products also contain substantial amounts of saturated fat, which might
offset some of the beneficial effects of dairy products. In this study,
magnesium and potassium intake was associated with lower blood
pressure, but calcium was not.”
researchers used data from food questionnaires from 4,797 men and women
participants in the National Heart, Lung, and Blood Institute’s
Family Heart Study. Participants consisted of 45 percent men, 55
percent women with an average age of 52 years. Four percent of the
participants were black. The goal of this multi-center,
population-based study is to identify and evaluate genetic and
non-genetic causes of coronary heart disease, atherosclerosis and
cardiovascular risk factors, such as HBP.
“Our data showed that people who ate more dairy products had lower systolic blood pressure,” Djoussé said.
blood pressure is the first (higher) number in a blood pressure
reading; it indicates the pressure in the arteries when the heart
beats. The lower (diastolic) number represents the pressure when the
heart muscle is at rest between beats.
from the Framingham Heart Study have shown that systolic blood pressure
is a better predictor of cardiovascular disease in a dose-response
fashion,” Djoussé said. “This means the higher your
systolic pressure, the higher your risk of cardiovascular
divided participants into four groups based on their daily dairy
intake. The highest dairy group said they ate more than three servings
of dairy per day, while the lowest dairy group averaged less than half
a serving of dairy per day. Systolic blood pressure was 2.6 millimeters
of mercury (mm Hg) lower on average for people eating the most dairy
than for those eating the least dairy.
researchers divided the groups by those who ate below the average
amount of saturated fat and those who ate above the average amount of
saturated fat, the effects of high-dairy consumption on systolic blood
pressure was only seen in people who ate below the average amount of
saturated fat. In this group, those who ate the most dairy had a
systolic pressure that was 3.5 mm Hg lower than those who ate the least
in a multivariable model that controlled for age, gender, education,
energy intake, body mass index, alcohol consumption, history of
coronary heart disease, diabetes and other variables, those who ate the
most dairy had a 36 percent lower odds of having HBP than those who ate
the least dairy.
participants who ate below the average amount of saturated fat, those
who also ate the most dairy had 54 percent lower odds of HBP than those
who ate the least amount of dairy.
data showed that dairy consumption is inversely associated with
prevalent high blood pressure and resting systolic blood pressure,
mainly among individuals consuming less saturated fat and independent
of the amount of dietary calcium,” Djoussé said. “It
is possible that nutrients other than calcium found in dairy products
may be responsible for these findings.”
people who reported eating the least amount of dairy products may have
other dietary habits that account for their higher blood pressure. In
this study, participants in the low-dairy group reported eating more
butter, hot dogs, burgers and eggs than those in the higher dairy
group, he said.
cross-sectional design of this study limits the ability to draw a
causal relationship between dairy consumption and blood pressure, he
said, adding that further study is needed.
are James S. Pankow, Ph.D.; Steven C. Hunt, Ph.D.; Gerardo Heiss, M.D.,
Ph.D.; Michael A. Province, Ph.D.; Edmond K. Kabagambe, M.S., Ph.D.;
and R. Curtis Ellison, M.D.
The National Heart, Lung, and Blood Institute funded the study.
information on the American Heart Association visit
www.americanheart.org and for more information on the Harvard Medical
School, visit http://hms.harvard.edu/hms.