thanks again for joining us
Mediterranean diets they're healthy
they're in the news all the time how do
they compare to other kind of diets and
is there a little bit of mythology in
all of this what I thought I might do is
talk about Mediterranean diets and
contrast them with vegan diets and other
diets and I think what we're gonna see
is that it's not one versus the other
they overlap in big ways but let's have
a look a vegan diet means that you're
eating fruits and grains and legumes and
vegetables and it can be interpreted in
all different ways a vegan diet means
grains and fruits and vegetables legumes
could have nuts and seeds but it
excludes animal products and that could
be an Italian meal obviously that could
be Mexican with beans and rice and
veggie fajitas it could be interpreted
through Chinese cuisine so vegan is not
a cuisine obviously it's not a part of
the world it just means certain things
are excluded
it could be Japanese now a Mediterranean
diet actually means I'm driving down the
coast of Tuscany and I don't really care
what I eat because it's just so darn
beautiful here and the notion of a
Mediterranean diet as a term was coined
by Ansel keys who was at the University
of Minnesota and one February morning he
looked out of his window thinking why am
I here
and he thought wouldn't it be nice to be
in southern Italy and found through some
really innovative research at the time
that diet made a big difference in
whether you lived or died from
cardiovascular disease and Italy did not
do the best but it was pretty good if
you see on this graph Japan had the
lowest degenerative heart disease death
rates Italy was second so the idea of
the Mediterranean diet was born to look
at the diets of that region now the
Mediterranean region is vast it includes
all of North Africa parts of the Middle
East and all across the bottom of Europe
but what Keyes had in mind was really
southern Italy and its neighbors to the
east and to the west so Greece France
and maybe parts of Spain and the diet
has had all different kinds of meanings
but it has been codified to mean lots of
plant foods not so much processing
desert is not going to be pudding it'll
be fruit if you use fat it would be
olive oil dairy products are low eggs
are low meat is low and wine is consumed
in low to moderate amounts one thing is
important he when Kees was using
archetypal Italian villages to design
with the diet meant he was looking at a
place called Nicotero in particular the
fat content of their diet was 23% of
calories so in other words relatively
low for all those people who imagine
that a Mediterranean diet means opening
up a bottle of olive oil and drowning
your food in it not their fat content
was much less than ours is here in North
America ok so the basics let's go back
and just talk about what are we trying
to get a diet to accomplish with regard
to heart disease of course the higher
your cholesterol level the higher your
risk of dying of coronary disease and so
what makes your cholesterol go up well
saturated fat the solid fat every one
percent rise in your saturated fat
intake will lead to roughly a 2 percent
rise in LDL and despite the egg industry
trying to make cholesterol look ok
dietary cholesterol does contribute to
plasma cholesterol as well so which
foods have them and if you look at
animal products and if you contrast them
with plant products you see something
quite dramatic animal products have
cholesterol and they have a substantial
amount of saturated fat plant products
have no cholesterol and are
extraordinarily low in saturated fat in
most cases by the way let's take a look
at chinook salmon you see that up there
for all the people who imagine that
wild-caught Sam
is somehow low in saturated fat or low
in cholesterol it's much more like beef
than it is like broccoli okay
now what about things that we wish our
foods did have like fiber or vitamin C
so animal products are not plant derived
they don't have fiber they don't have
vitamin C but you see lots of it in
plant foods lots of fiber lots of
vitamin C and other antioxidants as well
okay so there have been a number of
clinical trials on plant-based diets and
Dean Ornish did his elegant studies and
although he described them yesterday I
want to just go back over some of the
really key points he wanted to see if we
could not prevent heart disease but
reverse it with a four step program of
vegetarian foods half hour walk managing
stress which is why no physicians were
in the study avoid tobacco and after a
year the experimental group had a
massive drop in total cholesterol and in
LDL compared to an untreated control or
a usual care control group their weight
loss was impressive despite the fact
that there was no calorie counting and
what made medical history was an
geographic evidence that the arteries
were opening up and you could see this
in a year's time with no medication in
82 percent of patients a similar trial
was done in India to see if in a very
different population
you could have similar results so in
Northwest India in Rajasthan the Mount
Abu open heart trial began patients with
moderate to severe coronary
atherosclerosis and they were given a
vegetarian diet that was near vegan and
exercises stress management was part of
it as well and then they asked the
people oh no use of medication
challenging to do that nowadays since
everyone is on vitamin L but nonetheless
when they the researchers did
angiography
at baseline and at two years they then
separated the results based on adherence
to the
program and the high adherers had a 91%
91% of the high adherers had regression
of their lesions the low adherers only
12% and if you look at how many of them
had lesions regressing more than 10
percent 15 that was 51% of them and the
high adherence group and then if you
looked at the average diameter percent
diameter changes 18 absolute percentage
points in the high adherers this is like
really nice result so a Mediterranean
diet has been tested for primary
prevention and you heard about the
printed trial but let me walk you
through the weeds on what the trial was
attempting to do it occurred in Spain
starting in 2003 and it was a big trial
and very carefully put together more
than 7,000 participants and the average
person was overweight the average person
was 67 years old and they were split
into three groups one group got a
Mediterranean diet in a minute I'll tell
you what that meant to them plus olive
oil and the idea is the olive oils can
be healthy for you and they asked them
to have 50 grams of olive oil a day
about four tablespoons but what they
actually did was they delivered to each
participant a leader of olive oil per
week so they made sure that nobody was
low on olive oil the next group got the
Mediterranean diet but instead of olive
oil they were asked to have nuts roughly
an ounce a day of 30 grams and then
third group was the control group okay
so three groups and then what the
Mediterranean diet itself was was oil
nuts fruits vegetables fish legumes and
there's a tomato sauce that's popular in
Spain called sofrito and wine for people
who drank wine and the s/m not to have
sodas or baked goods or fatty spreads
like margarine butter and to favor white
meat over red meat but they weren't
necessarily pushing me so this is what
people actually ate and let me interpret
this for you the yellow bars that's the
group that was given the olive oil and
the brown bars are the group that was
given asked to eat nuts and the white
are the control group
so we could see the yellow bars on the
far left the extra-virgin olive oil in
take went way up in the group that was
asked to eat extra-virgin olive oil but
they reduced their risk of refined oils
so it wasn't that oily of a diet they
were eating the olive oil they were
given and not using other oils you'll
notice that their vegetable intake went
up in all the group's fruit intake went
up in all the group's fish went up a
little bit
meat went down dairy went down and lest
we imagine that the Mediterranean diet
is all red wine all the time alcohol did
not go up okay so this is three months
in let me show you the end of the study
pretty much the same olive oil way up in
the olive oil group nuts up in the nuts
group but meat and dairy down in both
and alcohol not really emphasized
alright so what happened well weight
loss didn't really work out so well they
lost about this is the first three
months of the study they lost about what
a quarter of a kilogram and ninety
percent of the participants are
overweight and to be on a special diet
to be monitored this way they only lost
about a quarter of a kilogram and then
when they looked at did you die this is
all cause mortality and you do see a
suggestion of a benefit for the olive
oil group but the p-value there 0.15
it's nowhere near significance and then
how about do you have you died of
cardiovascular disease once again a
suggestion of a benefit for the oil
group but there was so much variability
that the p-value was just not
significant so this couldn't be
differentiated from a chance result but
after about five years if you did a
composite of did you have a myocardial
infarction or stroke or did you die from
cardiovascular disease the control group
four point four percent
olive oil group three point eight
percent the nut group three point four
percent okay we're at least getting
somewhere and that was it that was the
headline that you got this rather modest
reduction from this composite endpoint
now I'm not saying it's bad or a poorly
done study
but some people were disappointed that
they couldn't get more out of it so the
researcher said well wait let's look at
those participants in the Preda med
trial who ate more or less like
vegetarians and the food the foods they
considered vegetarian foods were fruits
and vegetables and nuts and cereals
legumes olive oil potatoes including
french fries potato chips this wasn't a
question of quality it was just
are you eating these foods and avoiding
the animal products and they made a
score called the Pro vegetarian score
and what they showed was that the
further you went out the more you were
eating like a vegetarian they'll lower
your risk of dying of anything and the
p-value was 0.02 so statistically
significant and then specifically
cardiovascular mortality same story in
other words is this clear the more
people adhered to a vegetarian diet
avoiding the animal products and
including plant products the better they
did and the results were really quite
dramatic more so than the overall study
results and that matched what had been
seen right next door in Greece in the
epic cohort which is a large group of
people who have been studied when you
look at who lives and who dies in any
given window of time the foods that
reduce the risk of dying are vegetables
legumes fruits and nuts cereals and ma
high monounsaturated - saturated fat
ratio more olive oil less butter the
foods that are associated with mortality
are fish dairy meat and people who don't
drink enough and people who drink too
much so sort that out however you want
to alright so Mediterranean diets have
also been used for secondary prevention
the Leone trial looked at individuals in
around the old France 600 of them they
had already had a myocardial infarction
and the question is are you gonna have
another one are you gonna die and so
they split them into two groups and one
group got a Mediterranean diet plus a
margarine that was loaded with al
alpha-linolenic acid this is the omega-3
the 18 carbon omega-3 that your body
hopefully lengthens and the other group
got nothing so what happened when you
look at their dietary intake both groups
increase their vegetables then they
increase their fruit a lot and both
groups are eating some fish and some
meat and some high-fat dairy but after
27 months there wasn't much of any
effect on weight and I didn't include
baseline weight they didn't they were
actually heavier during the intervention
in both groups than they were at
baseline and if you look at their blood
pressure you don't see much advantage if
you look at their lipids do you make
anything out of that really not I mean
their total cholesterol in the two
groups about the same same with LDL
however if you look at their plasma
linolenic acid it went up and their EP a
which is the 20 carbon omega-3 that
comes from it that went up and their
plasma ascorbic acid vitamin c went up
too okay so their lipids aren't any
better really and their blood pressures
not better and their weight isn't any
better but something is happening in
their blood so let's look at see cardiac
deaths be in the experimental group
there were three deaths in the control
group 16 okay
cardiac deaths and non-fatal mi-8 in the
experimental group 33 in the control
group okay now this is looking
impressive despite the fact that our
typical measures weren't really
improving very much so if you ask the
authors why did the participants do
better on this diet despite the fact
they didn't lose any weight and their
lipids were no better they would say we
gave them a margarine that was loaded
with omega-3 and that helped them it's
anti thrombotic and anti-arrhythmic and
with vitamin C and vitamin E you've got
an antioxidant effect that's going to
help them as well okay yesterday dr.
Freeman talked about heart failure and
the medet a hf study looked at heart
failure it was an observational study
991 patients everybody had heart failure
mean age 80 years old
and they classified the patients these
heart failure patients as either
adherent to a Mediterranean pattern or
not adherent to a Mediterranean pattern
the question was does a Mediterranean
dietary pattern help you if you have
heart failure and here's what they found
for whether you're gonna die of anything
then non-adherent people did marginally
worse than the adherent people or to put
it the other way the adherent people did
a little better but not statistically
significant difference on the other hand
if you looked at were you hospitalized
again okay we're getting somewhere that
was a significant reduction in the
likelihood of being back in the hospital
so that suggests that a Mediterranean
dietary pattern ought to be helpful for
heart failure
so the predamond researcher said alright
let's look at that we're not an
observational study we're an
intervention trial and we can see if it
helps so again they brought the
individuals in who were average age 67
years old and as a sub study they looked
at the heart failure and I have to say
they didn't find much of anything
there was a modest suggestion of a
benefit for the olive oil group but it
was nowhere near statistical
significance unfortunately so their
conclusion was at least in their hands
doing the Mediterranean diet in this way
it was not really an effective treatment
for heart failure that does not mean
that I cannot be effective for heart
failure but some would argue that we got
to go a little bit further so let me
shift gears a little bit and talk about
tackling the risk factors first is
weight loss our research team brought in
64 overweight women and asked them to
change their diets either a vegan diet
or a National cholesterol education
programs step 2 diet that's chicken and
fish and no calorie limits no exercise
no food given to them they had to make
their own food but the typical day's
meals are things that would be familiar
to you like blueberry pancakes the fat
intake dropped in both groups especially
the vegans carbohydrates went way up in
the vegan group down in the other group
however the vegan group lost
substantially more body weight five
point eight kilograms compared to three
point eight kilograms in the other group
that was significant after two years the
control group regained its weight the
vegans never did they were skinny or at
two years than before and when you look
at every study ever done on plant-based
diets and body weight they show a very
consistent finding the zero line is on
the right all the studies show weight
loss okay all right why well the first
is you're eating more fiber fiber has
effectively no calories so your foods
are less energy dense and fat has nine
calories in every gram as opposed to
carbohydrate which has only four so if
you're eating more carbs you're getting
fewer calories and that's part of why
when you emphasize these plant-based
foods with the low fat intake people
tend to lose weight all right
cheese unfortunately a 70% fat for any
worse it would be Vaseline the next
thing fat in foods adds easily to body
fat your body can turn bread into body
fat but that's a challenge for it it
would much rather use it for blood sugar
or turned it into glycogen but it's
really easy for cheese to go to body fat
it's already fat and and I oh this is a
Kevin hall study that he mentioned
yesterday where Hughes used isocaloric
diets low fat low carb the low fat group
lost about 89 grams of fat per day which
was more than the low carb group
our research team under Hannah's
Direction has looked at the after meal
calorie burned the thermic effect of
food in patients when you eat lunch or
breakfast your calorie burn always
increases for three four or five hours
but after people have been on a low-fat
vegan diet it's substantially higher
about 16% higher so what we are
suggesting is that a fatty diet slows
metabolism let me walk you through why
that is
this was done at Pennington in Louisiana
they brought individuals in game of 50%
50% fat diet and showed that their
mitochondrial biogenesis slowed down
what I mean is in your cells you've got
mitochondria they burn things when you
fill yourselves with grease the
mitochondria don't work as well anymore
here all these mitochondria are trying
to function but as your diet packs fat
into the cells the mitochondria work
less effectively fat in cells slows down
your after meal burn so on a low-fat
vegan diet the fat dissipates the
mitochondria recover you get a better
burn so another possibility comes from
the gut microbiome and this is somewhat
speculative but the bacteria in your gut
make endotoxins that can pass into your
bloodstream and they can interfere with
the cells and at Virginia Tech
researchers gave a high-fat diet to
volunteers and their idea was that it
might the endotoxin from the bacteria in
the gut
would pass through the digestive tract
more easily on a high-fat diet and that
that in turn would disrupt cellular
metabolism is that true well they used a
55% fat diet for exactly five days and
what they showed is that this the amount
of endotoxin in the blood went right up
okay this is the bacterial poisons
getting into the blood and then they
looked at if I have a meal does my
glucose oxidation rise as it should or
does it not normally you eat you oxidize
and in the left before the high-fat diet
they did but after the high-fat diet
they did not so that what's what we
think is happening is a high-fat diet
somehow causes endotoxins to be swept
from the digestive tract into the
bloodstream interfering with cellular
metabolism theory but stand by okay just
finishing up LDL drops very consistently
blood pressure drops very consistently
on plant-based diets and a1c drops in
I'm gonna skip through this in interest
of time when fat gets into the muscle
cells and the liver cells it interferes
with insulins
ability to work and that's why if a
person has diabetes you don't want to
tell them to not eat rice and not eat
beans you want to tell them to stop
eating cheese and meat and other foods
that pack fat into the cells that allows
insulin sensitivity to improve okay it
and diets have been compared through a
study called the car to veg diet a
carnival study they compared a
Mediterranean diet to a vegetarian diet
118 overweight adults they had high
lipids or high glucose no medication use
three months diet period and they were
isocaloric diets either Mediterranean or
vegetarian and what they showed is that
total cholesterol dropped more in the
vegetarian diet than the Mediterranean
which is what you'd expect and LDL
dropped more as well triglycerides went
up a little bit in the vegetarian group
but really relatively trivially from
about 110 to about 115 and HDL didn't
really do much of anything in either one
mike Danziger at tufts compared four
different diets for their weight loss
effect low-carb macronutrient balance
which is a little bit like Mediterranean
versus a caloric restriction or an
orange type diet and showed the diets
are all about the same with regard to
long-term weight loss although there was
a little bit of an advantage for the
Ornish diet but when you put weight loss
together for all of these studies
whether it's the leone trial or the
printer med trial Mediterranean diets
really are not good for weight loss but
plant-based diets are really rather
consistently good so where does this
leave us there is a whole range of diets
out there from Western to prudent all
the way out to say vegan macrobiotic or
raw those are ideas of what would be in
the diet but they can be interpreted
through Mediterranean cuisine Asian
cuisine African cuisine Latin American
cuisine in other words you can be
Mediterranean and vegan or a
Mediterranean and an omnivore so what I
take from this is that the Mediterranean
pattern is a good one
but we want to have it
be as plant-based as possible so summary
we want to shift from animal-based foods
to plant-based foods
Mediterranean diets are heart healthy to
the extent that they emphasize plant
foods but we have lots of issues that
the research and doing this properly so
anyway I hope this has been helpful to
you and thank you very much
[Applause]
What's healthier: a vegan diet or the Mediterranean Diet? Neal Barnard, M.D., clears up the confusion in a presentation from the International Conference on Nutrition in Medicine on Aug. 10, 2018 in Washington, D.C. Learn more about a plant-based diet at PCRM.org.