|
 “A Mediterranean diet rich in virgin olive oil improves the function
of high-density lipoproteins, HDL, popularly known as `good’
cholesterol,” said lead study author Dr. Alvaro Hernáez of the
Hospital del Mar Medical Research Institute in Barcelona.
This type of diet typically includes lots of fruits and legumes that
are rich in antioxidants as well as plenty of vegetables, whole
grains and olive oil. It also tends to favor lean sources of protein
like chicken or fish over red meat, which contains more saturated
fat.
“Our hypothesis is that these dietary antioxidants may bind to HDL
particles and protect them against different kinds of attacks,”
Hernáez said by email. “As HDLs are more protected, they can perform
their biological functions more efficiently and, therefore, they are
able to remove cholesterol from arteries or contribute to the
relaxation of blood vessels for longer.”
High levels of low density lipoproteins (LDL) or “bad” cholesterol
and fats known as triglycerides are associated with an increased
risk of heart and blood vessel diseases. HDL, or “good,” cholesterol
is associated with a lower risk because it helps remove excess LDL
from the bloodstream.
For the current study, Hernáez and colleagues examined data on 296
older adults at risk for cardiovascular disease who were randomly
assigned to one of three diets: a Mediterranean diet supplemented
with one liter per week (about 34 fluid ounces) of extra virgin
olive oil, a Mediterranean diet supplemented with 30 grams (1 oz) of
nuts a day, or a low-fat diet.
Participants were 66 years old on average, and they were asked to
follow their assigned diet for one year.
Only the low-fat diet was associated with reduced LDL and total
cholesterol levels, researchers report in a paper scheduled for
publication in the journal Circulation.
None of the diets increased HDL levels significantly.
But blood tests and lab work showed better HDL functioning in the
group assigned to the Mediterranean diet with extra olive oil.
While some previous research has linked a Mediterranean diet to
weight loss and a reduced risk of heart disease and some cancers,
scientists haven't conclusively proven that the diet itself is
responsible, instead of other lifestyle choices made by people who
eat this way.
[to top of second column] |
Limitations of the current study include the fact that all three
diets were relatively healthy, making it difficult to detect
meaningful differences in outcomes, the authors note.
Still, the findings add to a growing body of research suggesting
that HDL function may influence cardiovascular disease risk, Dr.
Daniel Rader of the University of Pennsylvania in Philadelphia
writes in an accompanying editorial.
“We know the Mediterranean diet reduces risk of heart disease but
still don't know exactly why,” Rader said by email. “There is
probably more than one reason, and this study suggests that one
mechanism might be that the Mediterranean diet improves the function
of HDL.”
Even without clear evidence explaining why the Mediterranean diet
may help the heart, eating this way can still make sense, Rader
added.
“For people who are interested in reducing their risk of heart
disease, the Mediterranean diet is probably the best proven diet to
reduce risk,” Rader said. “I think the majority of people who don't
have other major dietary concerns should look toward the
Mediterranean diet as a heart healthy diet.”
SOURCE: http://bit.ly/2kqo3WZ and http://bit.ly/2kqeUO5 Circulation,
released February 13, 2017.
[© 2017 Thomson Reuters. All rights
reserved.] Copyright 2017 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
 |
