stroke risk factors
Update on Vegetarian Stroke Risk
"Update on Vegetarian Stroke Risk" Healthy plant-based diets
have been associated with lower all-cause mortality,
up to a 34 percent lower risk of death from any cause over an average
of an eight-year period, just being in the top
versus bottom quarter of healthy plant-based consumption. If sustained, that could translate
into more than four extra years of life. A meta-analysis of a dozen studies
prospectively following more than a half a million people
for up to 25 years similarly found significantly lower
heart disease and overall death rates among those eating more plant-based.
No surprise,
a systematic review concluded since plant-based diets
may arrest or even reverse our number one killer—
cardiovascular disease. Those eating wholly plant-based
tend to be significantly slimmer with lower LDL cholesterol, triglycerides,
blood sugars, blood pressures, significantly less inflammation,
and less carotid artery wall thickening (a sign of atherosclerosis measured
via ultrasound in the neck), as good as what you see
in endurance athletes who’ve run an average of 50,000 miles,
which is like twice around the globe. And changes in risk factors
can happen fast, as evidenced by results
from one to three-week ad libitum (eat-all-you-want)
plant-based “kickstart” programs. For example, the results from the first
few hundred participants of the at-home
15-day Jumpstart program created by the nonprofit Rochester
Lifestyle Medicine Institute were recently published. On a whole food plant-based diet,
obese patients lost an average of 7 pounds without controlling portions
or counting calories or carbs.
Diabetics saw their fasting blood sugars
drop 28 points. Those with LDL cholesterol
over 100 experienced a 33-point drop (comparable to some statin drugs), and hypertensive individuals
experienced a 17-point drop in systolic blood pressure,
which is better than drugs, and all within just two weeks! Studies dating back nearly 40 years
show those eating meat-free diets also have improved blood “rheology,”
meaning fluidity or flowability, which may play a role
in cardiovascular protection. Subsequent interventional studies putting
the cross-sectional findings to the test, show that switching people
to a plant-based diet can improve rheology measurements
within three to six weeks. But might the blood of vegetarians flow
a bit too well, though? In 2019, a study of thousands
of British vegetarians called EPIC-Oxford found that they were at higher risk
of hemorrhagic (bleeding) stroke. They had such a lower risk
of heart disease that they still had less
cardiovascular disease overall (and a half dozen studies show no overall
increased risk of stroke mortality), but why the greater stroke incidence? I suggested it might be vitamin B12
deficiency, which can lead to excessive levels
of a stroke- associated metabolite called homocysteine
which is normally detoxified by B12. This is thought to be the reason
why vitamin B12 supplementation can improve artery function
of vegetarians.
Vitamin B12 supplements
or fortified foods are critical for anyone eating plant-based,
but my 12-part video series on vegetarians and stroke risk
triggered by the 2019 publication was all in vain. It turns out vegetarians don’t appear
to have higher stroke risk after all. In response to the EPIC-Oxford results,
researchers around the world scrambled to see if the findings
were merely a fluke. In 2020, UK Biobank, a massive study
following more than 400,000 volunteers, confirmed that vegetarians
had lower cardiovascular disease rates and importantly,
no increased incidence of stroke. And two studies from Taiwan
found vegetarians had significantly
lower risk of stroke. Following tens of thousands
of vegetarians for up to ten years, they only had about half the stroke risk
compared to nonvegetarians (including a 64 percent lower risk
specifically of hemorrhagic stroke). By 2021, Harvard researchers
had finished and published their analyses of the 200,000+ participants
of the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals
Follow-Up Study. They too found no increased stroke risk
for vegetarians and indeed a decreased risk of stroke among those eating
healthy plant-based diets.
A meta-analysis putting all the studies
together found that indeed the EPIC-Oxford data appeared
to be a fluke after all, finding, if anything, a lower risk
of stroke in a subgroup analysis. A 2022 systematic review
concluded that vegetarian and low-animal product diets are associated with a significantly
lower risk of bleeding strokes, a significantly lower risk
of clotting strokes, and a significantly lower risk
of total strokes across the board..
Video Transcript – As found on YouTube
Update on Vegetarian Stroke Risk
"Update on Vegetarian Stroke Risk" Healthy plant-based diets
have been associated with lower all-cause mortality,
up to a 34 percent lower risk of death from any cause over an average
of an eight-year period, just being in the top
versus bottom quarter of healthy plant-based consumption. If sustained, that could translate
into more than four extra years of life. A meta-analysis of a dozen studies
prospectively following more than a half a million people
for up to 25 years similarly found significantly lower
heart disease and overall death rates among those eating more plant-based.
No surprise,
a systematic review concluded since plant-based diets
may arrest or even reverse our number one killer—
cardiovascular disease. Those eating wholly plant-based
tend to be significantly slimmer with lower LDL cholesterol, triglycerides,
blood sugars, blood pressures, significantly less inflammation,
and less carotid artery wall thickening (a sign of atherosclerosis measured
via ultrasound in the neck), as good as what you see
in endurance athletes who’ve run an average of 50,000 miles,
which is like twice around the globe. And changes in risk factors
can happen fast, as evidenced by results
from one to three-week ad libitum (eat-all-you-want)
plant-based “kickstart” programs.
For example, the results from the first
few hundred participants of the at-home
15-day Jumpstart program created by the nonprofit Rochester
Lifestyle Medicine Institute were recently published. On a whole food plant-based diet,
obese patients lost an average of 7 pounds without controlling portions
or counting calories or carbs. Diabetics saw their fasting blood sugars
drop 28 points. Those with LDL cholesterol
over 100 experienced a 33-point drop (comparable to some statin drugs), and hypertensive individuals
experienced a 17-point drop in systolic blood pressure,
which is better than drugs, and all within just two weeks! Studies dating back nearly 40 years
show those eating meat-free diets also have improved blood “rheology,”
meaning fluidity or flowability, which may play a role
in cardiovascular protection. Subsequent interventional studies putting
the cross-sectional findings to the test, show that switching people
to a plant-based diet can improve rheology measurements
within three to six weeks.
But might the blood of vegetarians flow
a bit too well, though? In 2019, a study of thousands
of British vegetarians called EPIC-Oxford found that they were at higher risk
of hemorrhagic (bleeding) stroke. They had such a lower risk
of heart disease that they still had less
cardiovascular disease overall (and a half dozen studies show no overall
increased risk of stroke mortality), but why the greater stroke incidence? I suggested it might be vitamin B12
deficiency, which can lead to excessive levels
of a stroke- associated metabolite called homocysteine
which is normally detoxified by B12.
This is thought to be the reason
why vitamin B12 supplementation can improve artery function
of vegetarians. Vitamin B12 supplements
or fortified foods are critical for anyone eating plant-based,
but my 12-part video series on vegetarians and stroke risk
triggered by the 2019 publication was all in vain. It turns out vegetarians don’t appear
to have higher stroke risk after all. In response to the EPIC-Oxford results,
researchers around the world scrambled to see if the findings
were merely a fluke. In 2020, UK Biobank, a massive study
following more than 400,000 volunteers, confirmed that vegetarians
had lower cardiovascular disease rates and importantly,
no increased incidence of stroke.
And two studies from Taiwan
found vegetarians had significantly
lower risk of stroke. Following tens of thousands
of vegetarians for up to ten years, they only had about half the stroke risk
compared to nonvegetarians (including a 64 percent lower risk
specifically of hemorrhagic stroke). By 2021, Harvard researchers
had finished and published their analyses of the 200,000+ participants
of the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals
Follow-Up Study. They too found no increased stroke risk
for vegetarians and indeed a decreased risk of stroke among those eating
healthy plant-based diets.
A meta-analysis putting all the studies
together found that indeed the EPIC-Oxford data appeared
to be a fluke after all, finding, if anything, a lower risk
of stroke in a subgroup analysis. A 2022 systematic review
concluded that vegetarian and low-animal product diets are associated with a significantly
lower risk of bleeding strokes, a significantly lower risk
of clotting strokes, and a significantly lower risk
of total strokes across the board..
Video Transcript – As found on YouTube
Update on Vegetarian Stroke Risk
"Update on Vegetarian Stroke Risk" Healthy plant-based diets
have been associated with lower all-cause mortality,
up to a 34 percent lower risk of death from any cause over an average
of an eight-year period, just being in the top
versus bottom quarter of healthy plant-based consumption. If sustained, that could translate
into more than four extra years of life. A meta-analysis of a dozen studies
prospectively following more than a half a million people
for up to 25 years similarly found significantly lower
heart disease and overall death rates among those eating more plant-based. No surprise,
a systematic review concluded since plant-based diets
may arrest or even reverse our number one killer—
cardiovascular disease. Those eating wholly plant-based
tend to be significantly slimmer with lower LDL cholesterol, triglycerides,
blood sugars, blood pressures, significantly less inflammation,
and less carotid artery wall thickening (a sign of atherosclerosis measured
via ultrasound in the neck), as good as what you see
in endurance athletes who’ve run an average of 50,000 miles,
which is like twice around the globe. And changes in risk factors
can happen fast, as evidenced by results
from one to three-week ad libitum (eat-all-you-want)
plant-based “kickstart” programs.
For example, the results from the first
few hundred participants of the at-home
15-day Jumpstart program created by the nonprofit Rochester
Lifestyle Medicine Institute were recently published. On a whole food plant-based diet,
obese patients lost an average of 7 pounds without controlling portions
or counting calories or carbs. Diabetics saw their fasting blood sugars
drop 28 points. Those with LDL cholesterol
over 100 experienced a 33-point drop (comparable to some statin drugs), and hypertensive individuals
experienced a 17-point drop in systolic blood pressure,
which is better than drugs, and all within just two weeks! Studies dating back nearly 40 years
show those eating meat-free diets also have improved blood “rheology,”
meaning fluidity or flowability, which may play a role
in cardiovascular protection.
Subsequent interventional studies putting
the cross-sectional findings to the test, show that switching people
to a plant-based diet can improve rheology measurements
within three to six weeks. But might the blood of vegetarians flow
a bit too well, though? In 2019, a study of thousands
of British vegetarians called EPIC-Oxford found that they were at higher risk
of hemorrhagic (bleeding) stroke. They had such a lower risk
of heart disease that they still had less
cardiovascular disease overall (and a half dozen studies show no overall
increased risk of stroke mortality), but why the greater stroke incidence? I suggested it might be vitamin B12
deficiency, which can lead to excessive levels
of a stroke- associated metabolite called homocysteine
which is normally detoxified by B12.
This is thought to be the reason
why vitamin B12 supplementation can improve artery function
of vegetarians. Vitamin B12 supplements
or fortified foods are critical for anyone eating plant-based,
but my 12-part video series on vegetarians and stroke risk
triggered by the 2019 publication was all in vain. It turns out vegetarians don’t appear
to have higher stroke risk after all. In response to the EPIC-Oxford results,
researchers around the world scrambled to see if the findings
were merely a fluke. In 2020, UK Biobank, a massive study
following more than 400,000 volunteers, confirmed that vegetarians
had lower cardiovascular disease rates and importantly,
no increased incidence of stroke.
And two studies from Taiwan
found vegetarians had significantly
lower risk of stroke. Following tens of thousands
of vegetarians for up to ten years, they only had about half the stroke risk
compared to nonvegetarians (including a 64 percent lower risk
specifically of hemorrhagic stroke). By 2021, Harvard researchers
had finished and published their analyses of the 200,000+ participants
of the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals
Follow-Up Study. They too found no increased stroke risk
for vegetarians and indeed a decreased risk of stroke among those eating
healthy plant-based diets. A meta-analysis putting all the studies
together found that indeed the EPIC-Oxford data appeared
to be a fluke after all, finding, if anything, a lower risk
of stroke in a subgroup analysis. A 2022 systematic review
concluded that vegetarian and low-animal product diets are associated with a significantly
lower risk of bleeding strokes, a significantly lower risk
of clotting strokes, and a significantly lower risk
of total strokes across the board..
Video Transcript – As found on YouTube
Update on Vegetarian Stroke Risk
"Update on Vegetarian Stroke Risk" Healthy plant-based diets
have been associated with lower all-cause mortality,
up to a 34 percent lower risk of death from any cause over an average
of an eight-year period, just being in the top
versus bottom quarter of healthy plant-based consumption. If sustained, that could translate
into more than four extra years of life. A meta-analysis of a dozen studies
prospectively following more than a half a million people
for up to 25 years similarly found significantly lower
heart disease and overall death rates among those eating more plant-based. No surprise,
a systematic review concluded since plant-based diets
may arrest or even reverse our number one killer—
cardiovascular disease. Those eating wholly plant-based
tend to be significantly slimmer with lower LDL cholesterol, triglycerides,
blood sugars, blood pressures, significantly less inflammation,
and less carotid artery wall thickening (a sign of atherosclerosis measured
via ultrasound in the neck), as good as what you see
in endurance athletes who’ve run an average of 50,000 miles,
which is like twice around the globe.
And changes in risk factors
can happen fast, as evidenced by results
from one to three-week ad libitum (eat-all-you-want)
plant-based “kickstart” programs. For example, the results from the first
few hundred participants of the at-home
15-day Jumpstart program created by the nonprofit Rochester
Lifestyle Medicine Institute were recently published. On a whole food plant-based diet,
obese patients lost an average of 7 pounds without controlling portions
or counting calories or carbs. Diabetics saw their fasting blood sugars
drop 28 points. Those with LDL cholesterol
over 100 experienced a 33-point drop (comparable to some statin drugs), and hypertensive individuals
experienced a 17-point drop in systolic blood pressure,
which is better than drugs, and all within just two weeks! Studies dating back nearly 40 years
show those eating meat-free diets also have improved blood “rheology,”
meaning fluidity or flowability, which may play a role
in cardiovascular protection. Subsequent interventional studies putting
the cross-sectional findings to the test, show that switching people
to a plant-based diet can improve rheology measurements
within three to six weeks. But might the blood of vegetarians flow
a bit too well, though? In 2019, a study of thousands
of British vegetarians called EPIC-Oxford found that they were at higher risk
of hemorrhagic (bleeding) stroke.
They had such a lower risk
of heart disease that they still had less
cardiovascular disease overall (and a half dozen studies show no overall
increased risk of stroke mortality), but why the greater stroke incidence? I suggested it might be vitamin B12
deficiency, which can lead to excessive levels
of a stroke- associated metabolite called homocysteine
which is normally detoxified by B12. This is thought to be the reason
why vitamin B12 supplementation can improve artery function
of vegetarians. Vitamin B12 supplements
or fortified foods are critical for anyone eating plant-based,
but my 12-part video series on vegetarians and stroke risk
triggered by the 2019 publication was all in vain. It turns out vegetarians don’t appear
to have higher stroke risk after all.
In response to the EPIC-Oxford results,
researchers around the world scrambled to see if the findings
were merely a fluke. In 2020, UK Biobank, a massive study
following more than 400,000 volunteers, confirmed that vegetarians
had lower cardiovascular disease rates and importantly,
no increased incidence of stroke. And two studies from Taiwan
found vegetarians had significantly
lower risk of stroke. Following tens of thousands
of vegetarians for up to ten years, they only had about half the stroke risk
compared to nonvegetarians (including a 64 percent lower risk
specifically of hemorrhagic stroke). By 2021, Harvard researchers
had finished and published their analyses of the 200,000+ participants
of the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals
Follow-Up Study. They too found no increased stroke risk
for vegetarians and indeed a decreased risk of stroke among those eating
healthy plant-based diets.
A meta-analysis putting all the studies
together found that indeed the EPIC-Oxford data appeared
to be a fluke after all, finding, if anything, a lower risk
of stroke in a subgroup analysis. A 2022 systematic review
concluded that vegetarian and low-animal product diets are associated with a significantly
lower risk of bleeding strokes, a significantly lower risk
of clotting strokes, and a significantly lower risk
of total strokes across the board..
Video Transcript – As found on YouTube
Do Vegetarians Really Have Higher Stroke Risk?
"Do Vegetarians Really
Have Higher Stroke Risk?" When ranked in order of importance,
among the interventions available to prevent stroke, the three
most important are probably diet, smoking cessation, and
blood pressure control. Most of us are doing pretty
good on smoking these days, less than half of us are exercising
enough, but according to the American Heart Association only 1
in a thousand Americans are eating a healthy diet, and fewer than 1 in 10
are even eating a moderately healthy diet. Why does it matter? Because diet is an important
part of stroke prevention. Reducing sodium intake, avoiding egg
yolks, limiting the intake of meat, and increasing the intake of whole grains,
fruits, vegetables and lentils. Like the sugar industry, the meat
and egg industries spend hundreds of millions of dollars on propaganda,
unfortunately with great success. I was excited to check out Box number 1,
and was then honored, when I did. The strongest evidence for stroke
protection is for increasing fruit and vegetable intake, with
more uncertainty regarding the role of whole grains, animal products, and
dietary patterns such as vegetarian diets. I mean one would expect they’d do great.
Meta-analyses have found that
vegetarian diets lower cholesterol and blood pressure, and enhance
weight loss, and blood sugar control, and vegan diets may work even better.
So, all the key biomarkers are going in the right direction, but
you may be surprised to learn that there hadn’t ever been any
studies on the incidence of stroke in vegetarians and vegans… until, now. And if you think that's surprising,
wait until you hear the results.
The risks of heart disease
and stroke in meat eaters, fish eaters, and vegetarians
over 18 years of follow-up. Yes, less heart disease
among vegetarians (by which they mean vegetarians and vegans combined) no surprise—been there, done
that, but more stroke. An understandable knee-jerk
reaction might be “Wait a second, who did this study?” But this is EPIC-Oxford, world-class
researchers whose conflicts of interest may be more likely to read “I was
a member of the Vegan Society.” What about overadjustment? If you crunch the numbers
over a ten-year-period they found 15 strokes for every thousand
meat-eaters compared to only 9 strokes for every thousand
vegetarians and vegans. Wait, so how can they say there
were more strokes in the vegetarians? This was after adjusting
for a variety of factors. For example, the vegetarians
were less likely to smoke; so, you want to cancel that
out by adjusting for smoking, so that you can effectively
compare the stroke risk of nonsmoking vegetarians
to nonsmoking meat-eaters.
If you want to know how a vegetarian
diet itself affects stroke rates, you want to cancel out these
non-diet-related factors. Sometimes, though, you can overadjust. The sugar industry does it all the time. This is how it works. Imagine you just got a grant
from the soda industry to study the effect of soda on
the childhood obesity epidemic. What could you possibly do after
putting all the studies together to arrive at the conclusion that
there was near zero effect of sugary beverage consumption
on body weight? Well, since you know that
drinking liquid candy can lead to excess calories that can lead
to obesity, if you control for calories, if you control for a factor
that’s in the causal chain, effectively only comparing soda
drinkers who take in the same number of calories as non-soda-drinkers
then you could undermine the soda-to-obesity effect, and
that’s exactly what they did.
That introduces overadjustment bias. Instead of just controlling
for some unrelated factor, you control for an intermediate
variable on the cause-and-effect pathway
between exposure and outcome. Overadjustment is how meat-and-
dairy industry funded researchers have been accused of obscuring
the true association between saturated fat and cardiovascular disease. We know that saturated
fat increases cholesterol which increases heart disease risk. Therefore, if you control for
cholesterol, effectively only comparing saturated fat eaters with the
same cholesterol levels as non-saturated-fat eaters,
you see how you could undermine the saturated fat-to-heart disease effect. Now let’s get back to this. Since vegetarian eating
lowers blood pressure, and a lowered blood pressure
leads to less stroke, controlling for blood pressure would be an
overadjustment, effectively only comparing vegetarians to meat-eaters
with the same low blood pressure. That’s not fair, since that’s one
of the benefits of vegetarian eating, not some unrelated factor like smoking; and so, it would undermine
the afforded protection. So, did they do that? No. They only adjusted for unrelated factors, like education, and socioeconomic class,
and smoking, and exercise, and alcohol. That’s what you want. You want to tease out the effects of a vegetarian diet on stroke risk…
you want to try to equalize everything else to tease out the
effects of just the dietary choice.
And since, for example, meat eaters
in the study were on average 10 years older than the vegetarians,
you can totally see how when you adjust for that
vegetarians could come out worse. Since stroke risk can increase
exponentially with age, you can see how having 9 strokes among
a thousand vegetarians in their 40s could be worse than 15 strokes among
a thousand meat-eaters in their 50s. The fact that vegetarians had
greater stroke risk despite their lower blood pressure suggests
there’s something about meat-free diets that so increases stroke risk it’s enough
to cancel out the blood pressure benefits, but even if that’s true you
still would want to eat that way. Stroke is our 5th leading cause of
death, whereas heart disease is #1. So, yes, in this study there
were this many more cases of stroke in vegetarians, but there were this many
fewer cases of heart disease, but if there is something increasing
stroke risk in vegetarians it would be nice to know what
it is in hopes of figuring out how to get the best of both worlds.
This is the question we'll turn to, next..
Video Transcript – As found on YouTube
Update on Vegetarian Stroke Risk
"Update on Vegetarian Stroke Risk" Healthy plant-based diets
have been associated with lower all-cause mortality,
up to a 34 percent lower risk of death from any cause over an average
of an eight-year period, just being in the top
versus bottom quarter of healthy plant-based consumption. If sustained, that could translate
into more than four extra years of life. A meta-analysis of a dozen studies
prospectively following more than a half a million people
for up to 25 years similarly found significantly lower
heart disease and overall death rates among those eating more plant-based. No surprise,
a systematic review concluded since plant-based diets
may arrest or even reverse our number one killer—
cardiovascular disease. Those eating wholly plant-based
tend to be significantly slimmer with lower LDL cholesterol, triglycerides,
blood sugars, blood pressures, significantly less inflammation,
and less carotid artery wall thickening (a sign of atherosclerosis measured
via ultrasound in the neck), as good as what you see
in endurance athletes who’ve run an average of 50,000 miles,
which is like twice around the globe.
And changes in risk factors
can happen fast, as evidenced by results
from one to three-week ad libitum (eat-all-you-want)
plant-based “kickstart” programs. For example, the results from the first
few hundred participants of the at-home
15-day Jumpstart program created by the nonprofit Rochester
Lifestyle Medicine Institute were recently published. On a whole food plant-based diet,
obese patients lost an average of 7 pounds without controlling portions
or counting calories or carbs. Diabetics saw their fasting blood sugars
drop 28 points. Those with LDL cholesterol
over 100 experienced a 33-point drop (comparable to some statin drugs), and hypertensive individuals
experienced a 17-point drop in systolic blood pressure,
which is better than drugs, and all within just two weeks! Studies dating back nearly 40 years
show those eating meat-free diets also have improved blood “rheology,”
meaning fluidity or flowability, which may play a role
in cardiovascular protection. Subsequent interventional studies putting
the cross-sectional findings to the test, show that switching people
to a plant-based diet can improve rheology measurements
within three to six weeks.
But might the blood of vegetarians flow
a bit too well, though? In 2019, a study of thousands
of British vegetarians called EPIC-Oxford found that they were at higher risk
of hemorrhagic (bleeding) stroke. They had such a lower risk
of heart disease that they still had less
cardiovascular disease overall (and a half dozen studies show no overall
increased risk of stroke mortality), but why the greater stroke incidence? I suggested it might be vitamin B12
deficiency, which can lead to excessive levels
of a stroke- associated metabolite called homocysteine
which is normally detoxified by B12. This is thought to be the reason
why vitamin B12 supplementation can improve artery function
of vegetarians. Vitamin B12 supplements
or fortified foods are critical for anyone eating plant-based,
but my 12-part video series on vegetarians and stroke risk
triggered by the 2019 publication was all in vain.
It turns out vegetarians don’t appear
to have higher stroke risk after all. In response to the EPIC-Oxford results,
researchers around the world scrambled to see if the findings
were merely a fluke. In 2020, UK Biobank, a massive study
following more than 400,000 volunteers, confirmed that vegetarians
had lower cardiovascular disease rates and importantly,
no increased incidence of stroke. And two studies from Taiwan
found vegetarians had significantly
lower risk of stroke. Following tens of thousands
of vegetarians for up to ten years, they only had about half the stroke risk
compared to nonvegetarians (including a 64 percent lower risk
specifically of hemorrhagic stroke). By 2021, Harvard researchers
had finished and published their analyses of the 200,000+ participants
of the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals
Follow-Up Study. They too found no increased stroke risk
for vegetarians and indeed a decreased risk of stroke among those eating
healthy plant-based diets.
A meta-analysis putting all the studies
together found that indeed the EPIC-Oxford data appeared
to be a fluke after all, finding, if anything, a lower risk
of stroke in a subgroup analysis. A 2022 systematic review
concluded that vegetarian and low-animal product diets are associated with a significantly
lower risk of bleeding strokes, a significantly lower risk
of clotting strokes, and a significantly lower risk
of total strokes across the board..
Video Transcript – As found on YouTube
Update on Vegetarian Stroke Risk
"Update on Vegetarian Stroke Risk" Healthy plant-based diets
have been associated with lower all-cause mortality,
up to a 34 percent lower risk of death from any cause over an average
of an eight-year period, just being in the top
versus bottom quarter of healthy plant-based consumption. If sustained, that could translate
into more than four extra years of life. A meta-analysis of a dozen studies
prospectively following more than a half a million people
for up to 25 years similarly found significantly lower
heart disease and overall death rates among those eating more plant-based. No surprise,
a systematic review concluded since plant-based diets
may arrest or even reverse our number one killer—
cardiovascular disease. Those eating wholly plant-based
tend to be significantly slimmer with lower LDL cholesterol, triglycerides,
blood sugars, blood pressures, significantly less inflammation,
and less carotid artery wall thickening (a sign of atherosclerosis measured
via ultrasound in the neck), as good as what you see
in endurance athletes who’ve run an average of 50,000 miles,
which is like twice around the globe. And changes in risk factors
can happen fast, as evidenced by results
from one to three-week ad libitum (eat-all-you-want)
plant-based “kickstart” programs.
For example, the results from the first
few hundred participants of the at-home
15-day Jumpstart program created by the nonprofit Rochester
Lifestyle Medicine Institute were recently published. On a whole food plant-based diet,
obese patients lost an average of 7 pounds without controlling portions
or counting calories or carbs. Diabetics saw their fasting blood sugars
drop 28 points. Those with LDL cholesterol
over 100 experienced a 33-point drop (comparable to some statin drugs), and hypertensive individuals
experienced a 17-point drop in systolic blood pressure,
which is better than drugs, and all within just two weeks! Studies dating back nearly 40 years
show those eating meat-free diets also have improved blood “rheology,”
meaning fluidity or flowability, which may play a role
in cardiovascular protection. Subsequent interventional studies putting
the cross-sectional findings to the test, show that switching people
to a plant-based diet can improve rheology measurements
within three to six weeks. But might the blood of vegetarians flow
a bit too well, though? In 2019, a study of thousands
of British vegetarians called EPIC-Oxford found that they were at higher risk
of hemorrhagic (bleeding) stroke.
They had such a lower risk
of heart disease that they still had less
cardiovascular disease overall (and a half dozen studies show no overall
increased risk of stroke mortality), but why the greater stroke incidence? I suggested it might be vitamin B12
deficiency, which can lead to excessive levels
of a stroke- associated metabolite called homocysteine
which is normally detoxified by B12. This is thought to be the reason
why vitamin B12 supplementation can improve artery function
of vegetarians.
Vitamin B12 supplements
or fortified foods are critical for anyone eating plant-based,
but my 12-part video series on vegetarians and stroke risk
triggered by the 2019 publication was all in vain. It turns out vegetarians don’t appear
to have higher stroke risk after all. In response to the EPIC-Oxford results,
researchers around the world scrambled to see if the findings
were merely a fluke. In 2020, UK Biobank, a massive study
following more than 400,000 volunteers, confirmed that vegetarians
had lower cardiovascular disease rates and importantly,
no increased incidence of stroke. And two studies from Taiwan
found vegetarians had significantly
lower risk of stroke. Following tens of thousands
of vegetarians for up to ten years, they only had about half the stroke risk
compared to nonvegetarians (including a 64 percent lower risk
specifically of hemorrhagic stroke).
By 2021, Harvard researchers
had finished and published their analyses of the 200,000+ participants
of the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals
Follow-Up Study. They too found no increased stroke risk
for vegetarians and indeed a decreased risk of stroke among those eating
healthy plant-based diets. A meta-analysis putting all the studies
together found that indeed the EPIC-Oxford data appeared
to be a fluke after all, finding, if anything, a lower risk
of stroke in a subgroup analysis. A 2022 systematic review
concluded that vegetarian and low-animal product diets are associated with a significantly
lower risk of bleeding strokes, a significantly lower risk
of clotting strokes, and a significantly lower risk
of total strokes across the board..
Video Transcript – As found on YouTube
Do Vegetarians Really Have Higher Stroke Risk?
"Do Vegetarians Really
Have Higher Stroke Risk?" When ranked in order of importance,
among the interventions available to prevent stroke, the three
most important are probably diet, smoking cessation, and
blood pressure control. Most of us are doing pretty
good on smoking these days, less than half of us are exercising
enough, but according to the American Heart Association only 1
in a thousand Americans are eating a healthy diet, and fewer than 1 in 10
are even eating a moderately healthy diet. Why does it matter? Because diet is an important
part of stroke prevention. Reducing sodium intake, avoiding egg
yolks, limiting the intake of meat, and increasing the intake of whole grains,
fruits, vegetables and lentils. Like the sugar industry, the meat
and egg industries spend hundreds of millions of dollars on propaganda,
unfortunately with great success. I was excited to check out Box number 1,
and was then honored, when I did. The strongest evidence for stroke
protection is for increasing fruit and vegetable intake, with
more uncertainty regarding the role of whole grains, animal products, and
dietary patterns such as vegetarian diets.
I mean one would expect they’d do great. Meta-analyses have found that
vegetarian diets lower cholesterol and blood pressure, and enhance
weight loss, and blood sugar control, and vegan diets may work even better.
So, all the key biomarkers are going in the right direction, but
you may be surprised to learn that there hadn’t ever been any
studies on the incidence of stroke in vegetarians and vegans… until, now. And if you think that's surprising,
wait until you hear the results. The risks of heart disease
and stroke in meat eaters, fish eaters, and vegetarians
over 18 years of follow-up.
Yes, less heart disease
among vegetarians (by which they mean vegetarians and vegans combined) no surprise—been there, done
that, but more stroke. An understandable knee-jerk
reaction might be “Wait a second, who did this study?” But this is EPIC-Oxford, world-class
researchers whose conflicts of interest may be more likely to read “I was
a member of the Vegan Society.” What about overadjustment? If you crunch the numbers
over a ten-year-period they found 15 strokes for every thousand
meat-eaters compared to only 9 strokes for every thousand
vegetarians and vegans.
Wait, so how can they say there
were more strokes in the vegetarians? This was after adjusting
for a variety of factors. For example, the vegetarians
were less likely to smoke; so, you want to cancel that
out by adjusting for smoking, so that you can effectively
compare the stroke risk of nonsmoking vegetarians
to nonsmoking meat-eaters. If you want to know how a vegetarian
diet itself affects stroke rates, you want to cancel out these
non-diet-related factors. Sometimes, though, you can overadjust. The sugar industry does it all the time. This is how it works. Imagine you just got a grant
from the soda industry to study the effect of soda on
the childhood obesity epidemic.
What could you possibly do after
putting all the studies together to arrive at the conclusion that
there was near zero effect of sugary beverage consumption
on body weight? Well, since you know that
drinking liquid candy can lead to excess calories that can lead
to obesity, if you control for calories, if you control for a factor
that’s in the causal chain, effectively only comparing soda
drinkers who take in the same number of calories as non-soda-drinkers
then you could undermine the soda-to-obesity effect, and
that’s exactly what they did. That introduces overadjustment bias. Instead of just controlling
for some unrelated factor, you control for an intermediate
variable on the cause-and-effect pathway
between exposure and outcome. Overadjustment is how meat-and-
dairy industry funded researchers have been accused of obscuring
the true association between saturated fat and cardiovascular disease. We know that saturated
fat increases cholesterol which increases heart disease risk. Therefore, if you control for
cholesterol, effectively only comparing saturated fat eaters with the
same cholesterol levels as non-saturated-fat eaters,
you see how you could undermine the saturated fat-to-heart disease effect.
Now let’s get back to this. Since vegetarian eating
lowers blood pressure, and a lowered blood pressure
leads to less stroke, controlling for blood pressure would be an
overadjustment, effectively only comparing vegetarians to meat-eaters
with the same low blood pressure. That’s not fair, since that’s one
of the benefits of vegetarian eating, not some unrelated factor like smoking; and so, it would undermine
the afforded protection. So, did they do that? No. They only adjusted for unrelated factors, like education, and socioeconomic class,
and smoking, and exercise, and alcohol. That’s what you want. You want to tease out the effects of a vegetarian diet on stroke risk…
you want to try to equalize everything else to tease out the
effects of just the dietary choice.
And since, for example, meat eaters
in the study were on average 10 years older than the vegetarians,
you can totally see how when you adjust for that
vegetarians could come out worse. Since stroke risk can increase
exponentially with age, you can see how having 9 strokes among
a thousand vegetarians in their 40s could be worse than 15 strokes among
a thousand meat-eaters in their 50s. The fact that vegetarians had
greater stroke risk despite their lower blood pressure suggests
there’s something about meat-free diets that so increases stroke risk it’s enough
to cancel out the blood pressure benefits, but even if that’s true you
still would want to eat that way. Stroke is our 5th leading cause of
death, whereas heart disease is #1. So, yes, in this study there
were this many more cases of stroke in vegetarians, but there were this many
fewer cases of heart disease, but if there is something increasing
stroke risk in vegetarians it would be nice to know what
it is in hopes of figuring out how to get the best of both worlds.
This is the question we'll turn to, next..
Video Transcript – As found on YouTube
Update on Vegetarian Stroke Risk
"Update on Vegetarian Stroke Risk" Healthy plant-based diets
have been associated with lower all-cause mortality,
up to a 34 percent lower risk of death from any cause over an average
of an eight-year period, just being in the top
versus bottom quarter of healthy plant-based consumption. If sustained, that could translate
into more than four extra years of life. A meta-analysis of a dozen studies
prospectively following more than a half a million people
for up to 25 years similarly found significantly lower
heart disease and overall death rates among those eating more plant-based.
No surprise,
a systematic review concluded since plant-based diets
may arrest or even reverse our number one killer—
cardiovascular disease. Those eating wholly plant-based
tend to be significantly slimmer with lower LDL cholesterol, triglycerides,
blood sugars, blood pressures, significantly less inflammation,
and less carotid artery wall thickening (a sign of atherosclerosis measured
via ultrasound in the neck), as good as what you see
in endurance athletes who’ve run an average of 50,000 miles,
which is like twice around the globe. And changes in risk factors
can happen fast, as evidenced by results
from one to three-week ad libitum (eat-all-you-want)
plant-based “kickstart” programs. For example, the results from the first
few hundred participants of the at-home
15-day Jumpstart program created by the nonprofit Rochester
Lifestyle Medicine Institute were recently published.
On a whole food plant-based diet,
obese patients lost an average of 7 pounds without controlling portions
or counting calories or carbs. Diabetics saw their fasting blood sugars
drop 28 points. Those with LDL cholesterol
over 100 experienced a 33-point drop (comparable to some statin drugs), and hypertensive individuals
experienced a 17-point drop in systolic blood pressure,
which is better than drugs, and all within just two weeks! Studies dating back nearly 40 years
show those eating meat-free diets also have improved blood “rheology,”
meaning fluidity or flowability, which may play a role
in cardiovascular protection.
Subsequent interventional studies putting
the cross-sectional findings to the test, show that switching people
to a plant-based diet can improve rheology measurements
within three to six weeks. But might the blood of vegetarians flow
a bit too well, though? In 2019, a study of thousands
of British vegetarians called EPIC-Oxford found that they were at higher risk
of hemorrhagic (bleeding) stroke. They had such a lower risk
of heart disease that they still had less
cardiovascular disease overall (and a half dozen studies show no overall
increased risk of stroke mortality), but why the greater stroke incidence? I suggested it might be vitamin B12
deficiency, which can lead to excessive levels
of a stroke- associated metabolite called homocysteine
which is normally detoxified by B12. This is thought to be the reason
why vitamin B12 supplementation can improve artery function
of vegetarians. Vitamin B12 supplements
or fortified foods are critical for anyone eating plant-based,
but my 12-part video series on vegetarians and stroke risk
triggered by the 2019 publication was all in vain.
It turns out vegetarians don’t appear
to have higher stroke risk after all. In response to the EPIC-Oxford results,
researchers around the world scrambled to see if the findings
were merely a fluke. In 2020, UK Biobank, a massive study
following more than 400,000 volunteers, confirmed that vegetarians
had lower cardiovascular disease rates and importantly,
no increased incidence of stroke. And two studies from Taiwan
found vegetarians had significantly
lower risk of stroke. Following tens of thousands
of vegetarians for up to ten years, they only had about half the stroke risk
compared to nonvegetarians (including a 64 percent lower risk
specifically of hemorrhagic stroke). By 2021, Harvard researchers
had finished and published their analyses of the 200,000+ participants
of the Nurses’ Health Study, the Nurses’ Health Study II, and the Health Professionals
Follow-Up Study. They too found no increased stroke risk
for vegetarians and indeed a decreased risk of stroke among those eating
healthy plant-based diets.
A meta-analysis putting all the studies
together found that indeed the EPIC-Oxford data appeared
to be a fluke after all, finding, if anything, a lower risk
of stroke in a subgroup analysis. A 2022 systematic review
concluded that vegetarian and low-animal product diets are associated with a significantly
lower risk of bleeding strokes, a significantly lower risk
of clotting strokes, and a significantly lower risk
of total strokes across the board..
Video Transcript – As found on YouTube
Vegetarians and Stroke Risk Factors—Vegan Junk Food?
"Vegetarians and Stroke Risk Factors
—Vegan Junk Food?" Plant-based diets are
associated with a lower risk of cardiovascular disease, mortality, and
dying from all causes put together. This study of a diverse sample
of 12,000 Americans found that “progressively increasing
the intake of plant foods by reducing the intake of
animal foods may be associated with benefits on cardiovascular
health and mortality…”, but when it comes to plant-based diets
for cardiovascular disease prevention, all plant foods are not created equal. Were the vegetarians in the
British study that found the higher stroke risk just
eating a lot of vegan junk food? Any diet devoid of certain
animal food sources can be claimed to be a
vegetarian or vegan diet; so, it’s important to see
what they’re actually eating. One of the first things I look
at when I’m trying to see how serious a population is
about healthy eating is look at something undeniably, uncontroversially
bad: soda, liquid candy. Anyone drinking straight
sugar water obviously doesn’t have health top of mind. In the big study of plant-based
eaters in America, where people tend to cut down
on meat for health reasons far more than ethics… flexitarians
drink fewer sugary beverages than regular meat-eaters, as do
pescatarians, vegetarians, and vegans.
In the UK study, though, where the
increased stroke risk was found, where folks are more likely to go
veg or vegan for ethical reasons, the pescatarians are drinking less soda, but the vegetarians and
vegans are drinking more. I’m not saying that’s
why they had more strokes; it just might give us an idea of
how healthy the people were eating. In the UK study, the vegetarians and
vegan men and women were eating about the same amount of
desserts, cookies, and chocolate, and about the same total sugar.
In the U.S. study, the average
non-vegetarian is nearly obese, even the vegetarians
are a little overweight, and the vegans were the
only ideal weight group. In this analysis of the UK study, though,
everyone was about the same weight— in fact the meat-eaters
were skinnier than the vegans. The EPIC-Oxford study seems to
have attracted a particularly health conscious group of meat-eaters weighing substantially less
than the general population. Let’s look at some particular
stroke-related nutrients. Dietary fiber appears beneficial
for the prevention of cardiovascular disease
including stroke, and it appears the more the better. Based on studies of nearly a half
a million men and women there doesn’t seem to be any
upper threshold of benefit; so, the more, the better. More than
25 grams of soluble fiber, 47 grams of insoluble dietary
fiber and you can really start seeing a significant drop
in associated stroke risk. So, one could consider these
as the minimal recommendable daily intakes to prevent
stroke at a population level. That’s what you see in people
eating diets centered around minimally processed plant foods.
Dean Ornish got up around there with his whole food plant-based diet.
Maybe not as much as
we were designed to eat, based on the analyses of fossilized feces, but that’s the kind of neighborhood
where we might expect significantly lower stroke risk. How much were the
UK vegetarians getting? 22.1. Now, in the UK they measure
fiber a little differently; so, that may actually
be closer to 30 grams, but not the optimal level
for stroke prevention. So little fiber that the vegetarians
and vegans only beat out the meat-eaters by about 1
or 2 bowel movements a week, suggesting they were eating
lots of processed foods.
The vegetarians were only
eating about a half serving more of fruits and vegetables,
thought to reduce stroke risk in part because of
their potassium content, yet the UK vegetarians at
higher stroke risk were evidently eating so few greens and beans they
couldn’t even match the meat-eaters, not even reaching the
recommended minimum daily potassium intake of 4700 mg a day. And what about sodium? The vast
majority of the available evidence indicates that elevated salt intake is
associated with higher stroke risk. There’s like a straight-line
increase in the risk of dying from a stroke
the more salt you eat. Even just lowering sodium intake
by a tiny fraction every year could prevent tens of
thousands of fatal strokes. Reducing sodium intake to prevent stroke:
time for action, not hesitation, but the UK vegetarians and
vegans appeared to be hesitating, as did the other dietary groups.
All groups exceeded the advised less than 2400 mg daily sodium intake—
and that doesn’t even account for salt added at the table, and
the American Heart Association recommends under just 1500 a day;
so, they were all eating lots of processed foods.
So, no wonder
the vegetarian blood pressures were only 1 or 2 points lower;
high blood pressure is perhaps the single most important modifiable
risk factor for stroke. What evidence do I have that if the
vegetarians and vegans ate better their stroke risk would go down?
Well, in rural Africa where they were able to nail the fiber intake that
our bodies were designed to get by eating so many whole healthy plant
foods— fruits, vegetables, grains, greens and beans, their protein
almost entirely from plant sources, not only was heart disease, our
#1 killer, almost non-existent, so apparently, was stroke, surging
up from out of nowhere with the introduction of salt
and refined foods to their diet. Stroke also appears to be
virtually absent in Kitava, a quasi-vegan island culture
near Australia where diet was very low in salt and
very rich in potassium, because it was a vegetable-based diet.
They ate fish a few times a week, but the other 95% or so
of their diet was lots of vegetables, fruits, corn, and beans,
and they had an apparent absence of stroke, even despite their
ridiculous rates of smoking.
After all, we evolved eating
as little as less than an 8th of a teaspoon a day of salt
and our daily potassium consumption is thought to have been
as high as like 10,000 mg. We went from an unsalted, whole-food
diet to salty processed foods depleted of potassium
whether we eat meat or not. Caldwell Esselstyn at the
Cleveland Clinic tried putting about 200 patients with established
cardiovascular disease on a whole food plant-based diet. Of the 177 that stuck with the diet
only one went on to have a stroke in the subsequent few years
compared to a hundred-fold greater rate of adverse events—
including multiple strokes and deaths in those that
strayed from the diet.
“This is not vegetarianism,”
Esselstyn explains. Vegetarians can eat a lot
of less-than-ideal foods. This new paradigm is exclusively whole
food, plant-based nutrition. Now this entire train of thought,
that the reason typical vegetarians don’t have better stroke statistics
is because they’re not eating particularly stellar diets, may
explain why they don’t have significantly lower strokes rates,
but that still doesn’t explain why they might have higher stroke rates.
Even if they’re eating similarly
crappy, salty, processed diets at least they’re not eating meat,
which we know increases stroke risk; so, there must be something
about vegetarian diets that so increases stroke risk that
it offsets their inherent advantages? We’ll continue our hunt, next..
Video Transcript – As found on YouTube
