"Plant-Based Diets and Artery Function"
Endothelial dysfunction is the initial step in the development
of peripheral artery disease, heart disease, and stroke.
The remarkable finding that progressive endothelial dysfunction,
the decline in the functioning of our arteries,
is not an inevitable consequence of aging,
that we can retain the arterial function we had in our 20's into our 60's
like the elderly Chinese, may in part be due to green tea.
But other important dietary differences include
increased consumption of vegetables and fish, with lower consumption
of other meat and dairy in the traditional Chinese diet, which may be
contributing to the protection observed in older Chinese arteries.
It's probably not the fish.
Pooling all the best double-blind, placebo-controlled studies found
that fish oil supplementation has no significant effect on endothelial function.
In by far the largest study done to date,
comparing doses of fish oil equivalent to 1, 2, or 4 servings of fish per week:
no effects of these long-chain omega 3 fats were found. This is consistent with
studies that have looked at whole fish consumption as well.
Overall, no significant association
between fish intake and endothelial function.
In fact, in women, those eating the most fish had the worst arterial function.
Women who ate fish more than twice a week had significantly impaired
endothelial function compared to those who never or only rarely ate fish.
So if it's not the fish, maybe it's the plants. Vegetarian diets appear to have
a directly beneficial effect on endothelial function.
Vegetarian arteries dilate four times better than omnivore arteries.
Maybe it's just because vegetarians tend to smoke less?
Within five minutes of smoking a single cigarette,
our endothelium is brought to its knees, completely clamped down,
and this happens if you're a smoker or simply breathing in second-hand smoke.
But this study excluded all smokers completely.
The beneficial effects were independent of non-dietary risk factors.
In fact, a healthy diet may even trump smoking.
The perseveration of endothelial function in older Chinese
may help explain why they have such low heart attack rates,
despite their high prevalence of cigarette smoking.
And the improved arterial function was well correlated
with the duration of eating vegetarian.
The longer they ate healthy,
the better their endothelial function appeared to be.
This was a cross-sectional study though, a snapshot in time,
so you can't prove cause and effect.
What we need is an interventional trial.
Put people on a plant-based diet and see if their arterial function improves,
which is exactly what Dr. Dean Ornish did,
showing a significant boost in arterial function compared to control.
Is this just some intangible risk factor test result though,
or does it actually have real world implications?
Are their arteries naturally dilating so much better
that their chest pain actually improves?
Ornish showed that on his plant-based diet and lifestyle program
cardiac patients had a 91% reduction in angina attacks.
In contrast, control group patients who were instead told to follow the advice
of their physicians had a 186% increase in reported angina attacks.
This marked reduction in frequency, severity, and duration
of angina chest pain was sustained five years later,
of five years of eating healthy.
A long-term reduction in angina comparable to that of surgery,
but without the knife.
But this was back in the '90s when Ornish was only studying
a few dozen patients at a time.
How about a thousand patients put on a healthy lifestyle track
with a whole-food, plant-based diet?
Within three months, nearly three-quarters of angina patients
became angina free.