|
A Mediterranean diet—rich in root and green vegetables,
grains, beans, and fish—reduced the risk of a second
heart attack by up to 70%, researchers say in a follow-up
to the Lyon Diet Heart Study (Circulation. 1999;99:779-785).
“This is the diet we've been looking for,”
said Thomas A. Pearson, MD, MPH, PhD, Professor of Medicine,
University of Rochester School of Medicine.
“Unlike many diet studies, this one had clinical
endpoints, with striking reductions in recurrent events
and death rates.”
Heart attack survivors placed on an alpha-linolenic–rich
Mediterranean diet experienced marked reductions in
MI recurrence, other cardiac events, and overall mortality.
Alpha-linolenic acid, a polyunsaturated fat, was significantly
associated with an improved prognosis, suggesting that
it may be the type of fat, not the amount, that matters.
The Mediterranean diet contained about 30% total fat,
with only 8% saturated. Participants were instructed
to consume more bread, more root and green vegetables,
more fish, less meat, fruit at least once daily, canola-based
margarine, and olive oil as a fat source.
Several years after randomization, most patients were
still following the diet; in contrast, most low-fat
diets have poor compliance.
The Lyon Diet Heart Study was a secondary-prevention
trial designed to assess whether a Mediterranean-type
diet can reduce the rate of recurrence after a first
MI. Six hundred and five patients were randomized to
an experimental diet or instructed to continue on a
prudent Western-type diet.
After 27 months mean follow-up, the benefits were so
favorable that the study's ethics committee terminated
what was intended to be a 5-year study. A 70% reduction
in all-cause mortality was reported in the intermediate
findings (Lancet. 1994;343:1454-1459).
The investigators continued to follow participants
(mean 46 months). In the final analysis, they report
that the protective effects of the diet were maintained
for up to 4 years after the first MI, confirming the
intermediate results.
The rate of cardiac death and nonfatal MI in the treated
group was 1.24 per 100 patients per year compared with
4.07 in the control group. Combined cardiac death and
nonfatal MI was 14 events in the treated group versus
44 in the control, and 27 versus 90, respectively, for
secondary endpoints (unstable angina, stroke, heart
failure, pulmonary or peripheral embolism).
A cardioprotective diet should be part of a comprehensive
program to reduce modifiable risk factors, the investigators
conclude, calling for future trials combining dietary
and pharmacologic interventions.
|