RHEUMATOID ARTHRITIS AND EATING HABITS
NEW YORK -- Results of a study of people living in
southern Greece suggest that eating hearty amounts of
olive oil and cooked vegetables may reduce the risk of
developing rheumatoid arthritis, researchers report.
Rheumatoid
arthritis is a
chronic inflammatory disease
of the joints. Its cause is unknown, but genes,
infectious agents, hormones, and diet have been
suggested as possible causes.
Some
reports have suggested
that fish oil and
vegetable oil in the diet may help relieve arthritis
symptoms, but research has not confirmed that these
foods have a protective effect. The new study findings
suggest that olive oil and cooked vegetables may, in
fact, reduce arthritis risk.
"Consumption
of both cooked
vegetables and olive oil
was inversely... associated with risk of rheumatoid
arthritis," according to the team of Greek and US
researchers, meaning that individuals who had higher
levels of these oils in their diets had a lower risk
of developing rheumatoid arthritis.
The
team did not find
evidence
that fish consumption
reduced the risk.
The
study was based on data
from 145 patients with
rheumatoid arthritis and 188 people who did not have
the disease. All of the study participants lived in
southern Greece and provided demographic,
socioeconomic, family and medical information.
The
consumption of more than
100 food items was
determined through interviews. The research team, led
by Athena Linos of the University of Athens Medical
School in Greece, estimated the number of days per
year that subjects consumed olive oil and tallied
these numbers to estimate consumption over a lifetime.
They then calculated the likelihood of developing
rheumatoid arthritis in relation to consumption of
olive oil, fish, vegetables, and other food groups.
The
investigators found that
people who consumed the
least olive oil were 2.5 times more likely to develop
rheumatoid arthritis than those who consumed the most
olive oil.
Further,
those who consumed
the
most cooked vegetables
had a 75% lower risk of developing rheumatoid
arthritis, they note.
Although
the mechanism by
which
these foods might
lower the risk remains unclear, the authors suggest
that antioxidant substances could play a role. Olive
oil is rich in vitamin E, which has "a beneficial
biological role as (a free) radical quencher." Free
radicals are molecules involved in several chronic
diseases as well as aging.
"It is
possible that heat
destroys the cell walls of
cooked vegetables, helping the body to absorb more of
a potentially beneficial substance," the team writes
in the December issue of the American Journal of
Clinical Nutrition. But they add that the "specific
beneficial substances in cooked vegetables remain to
be identified."
Linos
and colleagues also
note
that the typical
American diet is rich certain types of fat that are
broken down to hormones that promote inflammation. The
fatty acid in olive oil, on the other hand, is broken
down to hormones that inhibit inflammation.
SOURCE: American Journal of
Clinical Nutrition
1999;70:1077-1082.
