When it comes to heart health,
virgin olive oil may have an edge over other
vegetable fats, new research suggests.
Reporting in the Annals of Internal Medicine,
European researchers say virgin olive oil may
be particularly effective at lowering heart
disease risk because of its high level of antioxidant
plant compounds.
In a study of 200 healthy men, the researchers
found that virgin olive oil -- rich in antioxidants
called polyphenols -- showed stronger heart-health
effects than the more extensively processed
"non-virgin" variety.
The findings suggest that virgin olive oil
has more going for it than its supply of heart-healthy
monounsaturated fat, according to the study
authors. Polyphenols, they say, may account
for some of the health benefits that have
been attributed to the oil.
In fact, virgin olive oil is the only vegetable
oil that's rich in polyphenols, Dr. Maria-Isabel
Covas, the study's lead researcher stated.
"All vegetable oils other than virgin olive
oil are submitted to a (refining) process
in which polyphenols are practically lost,"
explained Covas, a researcher at the Municipal
Institute for Medical Research in Barcelona,
Spain.
Even "ordinary" olive oil has a lower polyphenol
content, she noted, because it's a mixture
of virgin olive oil and a more-processed form
of the oil.
For their study, Covas and her colleagues
had 200 young and middle-aged men use each
of three olive oils for three weeks apiece.
One oil was a virgin olive oil high in polyphenols;
the other two were more heavily processed
varieties with moderate to low polyphenol
levels.
The men used the oils in place of other dietary
fats.
At the end of the study, the researchers
found that the men's levels of "good" HDL
cholesterol were highest after their three
weeks on virgin olive oil. They also showed
a greater decline in markers of so-called
oxidative stress -- a process that helps deposit
particles of "bad" LDL cholesterol on the
artery walls and can lead to a hardening and
narrowing of the vessels supplying the heart.
Monounsaturated fat is well known to be a
healthier alternative to the saturated fat
found in animal products like butter, Covas
noted. That fact, along with the benefits
of polyphenols, she said, make olive oil "a
good source of fat."
But she stopped short of recommending virgin
olive oil as a replacement for other vegetable
oils, saying large clinical trials are needed
to see whether there's a health advantage.
SOURCE: Annals of Internal Medicine, September
5, 2006.
