Mediterranean-style diets, rich in healthy fats from
olive oil or nuts, may be better for the heart than
low-fat regimens, a new study shows.
Spanish researchers found that the traditional Mediterranean
diet bested a low-fat diet in helping older adults
improve their cholesterol, blood pressure and blood
sugar levels. The findings, published in the Annals
of Internal Medicine, add to evidence that diets rich
in healthy fats offer a better heart prescription
than diets that limit fat altogether.
Mediterranean-style eating generally means plenty
of fruits, vegetables and whole grains, limited amounts
of red meat and processed foods, and a relatively
high amount of fat from olive oil and nuts. Studies
have shown that people living in the Mediterranean
region have lower rates of heart disease, despite
their high fat intake.
Experts believe the benefit stems from the fact that
the unsaturated fats found in olive oil and nuts actually
help protect the cardiovascular system.
Olive oil is mostly monounsaturated fat, and virgin
olive oil -- which is minimally processed -- retains
the fruit's natural antioxidants, as well as nutrients
that may help reduce inflammation in the blood vessels.
Similarly, nuts contain unsaturated fats and other
nutrients thought to be heart-protective.
The researchers, lead by Dr. Ramon Estruch of the
University of Barcelona, found that it didn't matter
whether study participants got their healthy fat largely
from olive oil or from nuts. The subjects assigned
to either diet group that includes fats tended to
see greater improvements in cholesterol, blood pressure
and blood sugar than their peers who followed a low-fat
diet.
This means the effects of the Mediterranean diet
were moving "in the right direction," Estruch of the
University of Barcelona stated. Longer follow-up,
he said, is needed to see whether the benefits translate
into fewer heart attacks and strokes.
The study included 769 men and women between 55 and
80 years old who had type 2 diabetes or multiple other
risk factors for heart disease and stroke, such as
smoking, high blood pressure and heavy body weight.
For three months, participants followed one of three
diets: a low-fat regimen that advised cutting down
on all types of dietary fat; a Mediterranean diet
that emphasized virgin olive oil as the prime fat
source; or a Mediterranean diet in which walnuts,
hazelnuts and almonds provided a large amount of overall
dietary fat.
By the end of the study, those on either Mediterranean
diet showed small improvements in their "good" HDL
cholesterol levels, while the low-fat group showed
an HDL decline -- something that is known to happen
with low-fat diets.
Both Mediterranean diet groups also had an overall
improvement in blood pressure and blood sugar levels,
while those of the low-fat group were essentially
unchanged.
Men and women who got most of their fat from olive
oil also had a decline in a blood substance called
C-reactive protein, a marker of chronic inflammation
in the body.
The study did not assess whether virgin olive oil
or nuts were the healthier fat source, Estruch said,
and it's probably best to include both for a healthful
diet.
SOURCE: Annals of Internal Medicine, July 4, 2006.
