“Vegetarians and Stroke Risk Factors
—Omega 3s?” In my last video we started to explore “What might explain the higher
stroke risk in vegetarians?” found in the EPIC Oxford study.
Lower risk of heart disease, and lower risk of cardiovascular disease
overall, but higher risk of stroke. We looked into vitamin D
levels as a potential mechanism, but that didn’t seem to be the case.
What about long-chain omega 3s, the fish fats like EPA and
DHA, found, not surprisingly, in markedly lower levels in
vegetarians and vegans? About 30% lower in vegetarians
and more like half as low in vegans. But according to the most
extensive systematic assessment of effects of omega-3 fats on
cardiovascular health to date, there is no benefit for stroke, combining
28 randomized controlled trials. In fact, there was evidence
that taking fish oil didn’t help with heart disease or
overall mortality either. This may be because on one
hand the omega 3s may be helping, but the mercury in fish
may be making things worse. That’s the constant challenge
among public health professionals, balancing the benefits
with the contaminant risks. For example, dietary exposure
to PCBs may be associated with increased risk of stroke.
In this study, for instance, neither fish nor intake of PCBs
was related to stroke risk. However, at the same fish intake,
dietary PCBs were associated with an increased risk of stroke; so, the PCB pollutants may
be masking the fish benefit. Thus, if we had a time
machine and could go back before the industrial
revolution and find that fish in an unpolluted state it
might protect against stroke, but looking at the data,
if fish really was protective then we might expect that the
pescatarians, those who eat fish, but no other meat, to be
down here or something, since they would have the fish
benefit without the meat risk, but no, they’re stuck out here. So, it doesn’t seem to
be the omega 3s either. Let’s take a closer look at what the
vegetarians were actually eating. When it comes to plant-based diets
for cardiovascular disease prevention, all plant foods are not created equal. There are basically two
types of vegetarians: those that do it for their
health, and those that do it for ethical reasons, like
global warming, or animals. And they tend to eat different diets. For example, health vegans tend
to eat more fruit and less sweets. You don’t tend to see
those doing it for health chowing down on vegan doughnuts. In the United States,
the primary motivations for meat reduction are health and cost. A middle-class American family
is four times more likely to reduce meat
for health reasons compared to environmental or animal
welfare concerns. But in the UK, where the
stroke study was done, the #1 reason given for becoming
vegetarian or vegan is ethics. We know plant-based diets that
emphasize higher intakes of plant foods and lower intakes of animal foods,
are associated with a lower risk of incident cardiovascular
disease, a lower risk of dying from all causes put together, but
that’s only for healthy plant foods. Eating lots of Wonder Bread,
soda, and apple pie isn’t going to be doing you many favors. For all types of plant-based diets
it’s crucial that the choice of plant foods is given
careful consideration. We should be choosing whole
grains over refined grains, whole fruits, avoiding trans
fats, and added sugars. Could it be that the veggie Brits
were just eating more chips? We’ll find out, next. Video source: https://www.youtube.com/watch?v=7u0jC1nQgpM
