Mediterranean Diet and Atherosclerosis

“Mediterranean Diet and Atherosclerosis” The heart of a traditional
Mediterranean diet is mainly vegetarian, much lower in meat and dairy,
and uses fruit for dessert. So no surprise, those eating that way
had very low heart disease rates compared to those eating
standard Western diets. This landmark study, though,
has been cited to suggest that all types of fat, animal or vegetable,
was associated with the appearance of new atherosclerotic lesions in our
coronary arteries feeding our hearts. About a hundred men were given
angiograms at baseline, and then two years later, looking for
the development of lesions like this, before and after, all the while
monitoring their diets every year. Only about 1 in 20 eating lower
fat diets had new lesions, compared to about 8 in 20
on more typical American diets — around 33% or more fat. When they drilled down, though,
only three types of fat appeared to significantly increase the likelihood
of the appearance of new lesions: lauric, oleic, and linoleic. Lauric acid is a saturated fat found
in coconut oil, and palm kernel oil, which is found in junk food—
whipped cream, candy bars. Oleic, from the Latin word
oleum for olive oil, but that’s not where these men
were getting their oleic acid from. The top sources for Americans are
basically cake, chicken, and pork. And linoleic comes
mostly from chicken. So the study really just showed that
people eating lots of junk, chicken, and pork tended to close
off their coronary arteries. To see if major sources of plant fats
like olive oil or nuts help or hurt, ideally we’d do a multi-year
randomized study where you take
thousands of people and have a third eat nuts,
a third eat more olive oil, and a third do essentially nothing
to see who does better. And that’s exactly what was done. The PREDIMED study
took thousands of people at high risk for heart disease in
Spain, who were already eating a Mediterranean-ish diet, and
randomized them into three groups for a couple years: one with
added extra virgin olive oil, one with added nuts, and
a third group that was told to cut down on fat,
but they didn’t, so basically ended up as a
no dietary changes control group. What happened to the amount of
plaque in their arteries over time? Whereas there was significant worsening
of carotid artery thickening and plaque in the no dietary change control group,
those in the added nuts group showed a significant reversal in thickening,
an arrest in plaque progression. There were no significant changes
in the added olive oil group. The richness of the plant-based
Mediterranean diet in potentially beneficial foods, such
as fruit, vegetables, beans, nuts, whole grains and olive oil, is believed
to explain its cardioprotective effects, though these results suggest that nuts
really are a preferable source of fat to olive oil, and may delay
the progression of atherosclerosis, the harbinger of future
cardiovascular events such as stroke. Adding nuts appeared to
cut the risk of stroke in half. Note, though, they were
still having strokes. Half as many strokes, so the
nuts appeared to be helping, but they were still eating a diet
conducive to strokes and heart attacks. All three groups had basically
the same heart attack rates, the same overall death rates. That’s what Dr. Ornish
noted when he wrote in: no significant reduction in the rates of
heart attack, death from cardiovascular causes, or death from any cause,
just that stroke benefit. But hey, that’s something. A Mediterranean diet is certainly better
than what most people are consuming, but even better may be a
diet based on whole plant foods, shown to reverse heart disease,
not contribute to it. The authors of the
study replied that they didn’t wish to detract
from Ornish’s work, noting that Mediterranean and
plant-based diets actually share a great number of
foods in common. Yes, Ornish’s diet may reverse heart
disease, but the Mediterranean diet proponents argue, the
major problem with Ornish’s diet is that it doesn’t taste good
and so hardly anyone sticks to it.

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