Eat vegetarian and you’ll live longer. No brainer, right?
Actually, it’s complicated.
Most studies suggest that a vegetarian lifestyle gives you longer life. But some vegetarians do better on some measures than meat eaters—but
there are also some vegetarians who do far better than other vegetarians.
Spoiler alert: based on our review of the biggest
studies, you should eat mostly vegetarian, but eat some dairy and fish, too.
You’ll live longer than by eating a pure vegan diet.
Certainly not what we expected. So, what’s going on?
Heart disease is a major killer. It seems clear from most studies that a vegetarian or
largely vegetarian diet is associated with lower heart disease, especially in
men. A famous series of British studies found that 1 in 20 vegetarian men have
hypertension, while 3 in 20 meat eaters do. The numbers are less stark for
women, but they still hold. American studies have similar results.
But ultimately, one way of looking at the data with respect
to heart disease is that this particular study did not find that the vegetarian
diet made all the difference—rather that body weight did. “Non-meat eaters,
especially vegans, have a lower prevalence of hypertension and lower systolic
and diastolic blood pressures than meat eaters, largely because of differences
in body mass index.”
There’s more on fatness and mortality here. And here’s another.
So, what’s going on there?
This related study found that if you’re eating a high-fiber
diet that’s low in protein, you’re less likely to be fat. And the previous
study says if you’re less likely to be fat, you’re less likely to have high
blood pressure.
But here is perhaps the more interesting and perplexing
study result: Despite a higher death rate for people with high blood pressure,
the British studies on more than 50,000 individuals showed that the overall death rate of vegetarians studied wasn’t
much different than that of meat eaters.
That’s weird, right? Because it flies in the face of accepted
logic.
Well, there are a couple of things going on. One is that
even the British non-vegetarians in these studies may have been eating better
than the average Brit, since meat-eaters in this study have better health
outcomes than the national average. (One clue: part of the study involved
meat-eaters who shop at health food stores.)
When the massive British study is paired with an even bigger
study of American Seventh-Day Adventists, the picture gains some clarity, but
some more complexit.
It seems that British vegetarians eat a different vegetarian
diet than American Seventh-Day Adventist vegetarians do. Maybe not as good a vegetarian diet, in terms of promoting long life.
The British results, from what’s known as the EPIC-Oxford
studies, are very different in overall mortality from American ones in the
American Seventh-Day Adventist study by Loma Linda University School of Public Health researchers.
This one was on more than 96,000 American Seventh-Day Adventists, half of whom
follow some version of a vegetarian diet, but about half of whom don’t.
The American study found death rates among vegetarians was
significantly lower than among meat-eaters, but that the rates differed between different kinds of vegetarians.
The American Loma Linda researchers knew about the British study, and
looked into the differences. Their finding: “It appears that British
vegetarians and US Adventist vegetarians eat somewhat differently.”
And that matters. “Although vegetarian diets are healthful
and are associated with lower risk of several chronic diseases, different types
of vegetarians may not experience the same effects on health.” So says this study.
A big difference: American Seventh-Day Adventist vegetarians
ate far more fiber, and far more vitamin
C. Close to 70 percent more fiber and Vitamin C in the Americans. Maybe there
are other differences, too. But those stood out.
“… the vegetarians in our study consume more fiber and
vitamin C than those of the EPIC-Oxford cohort: mean dietary fiber in
EPIC-Oxford vegans was 27.7 g/d in men and 26.4 g/d in women compared with 45.6
g/d in men and 47.3 g/d in women in AHS-2 vegans; mean vitamin C in EPIC-Oxford
vegans was 125 mg/d in men and 143 mg/d in women compared with 224 mg/d in men
and 250 mg/d in women in AHS-2 vegans,” the Loma Linda study says.
Loma Linda researchers also noted that there are a lot of
different kinds of vegetarian eaters. Here’s the list Loma Linda used to
describe their sample: vegan (No red meat, fish, poultry, dairy or eggs); lacto-ovo
vegetarian (Consume milk and/or eggs, but no red meat, fish or poultry); pesco-vegetarian
(Eat fish, milk and eggs but no red meat or poultry); semi-vegetarian (Eat red
meat, poultry and fish less than once per week); non-vegetarian (Eat red meat,
poultry, fish, milk and eggs more than once a week).
In general, the more meat you eat, the poorer your outcome in these studies—with
one major caveat. People who ate fish with their vegetarian fare, even when
they included milk and eggs, were even less likely to die early than vegans.
© Jan TenBruggencate 2016
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