we've all been told a million times that
we should include
more fiber in our diet and we're given
multiple reasons for this
the purpose of this video is to question
how much
fiber should we be getting in our diet
and more importantly what does the
research
actually say about this not necessarily
epidemiological observational research
that's based on food
frequency questionnaires but what does
actual randomized control research
say about the fiber question i'm dr ken
berry a family physician with 20 years
of clinical practice
and this video is going to help you
understand how much fiber do you need to
eat each and every day
all you have to do is turn on the
television or read a magazine article or
jump on twitter
and you're going to be told things over
and over like
eating more fiber helps support weight
loss lowers your cholesterol
lowers your blood sugar improves your
heart health prevents diabetes
completely
helps constipation decreases your risk
of colon cancer or my personal favorite
that it detoxes some part of your
body now people who have ever taken
too much fiber either from fiber
containing foods
or from a fiber supplement will tell you
that the side effects of having too much
fiber are
no fun whatsoever they include gas
lots of gas bloating constipation
diarrhea wait a minute constipation
yeah and cramping and actually worsening
of irritable bowel syndrome
symptoms so it's it's almost like your
bowel is telling you
hey don't eat all this fiber but
many powers that be including the fda
and the american heart association say
hey you need to eat lots of fiber
if you're a man you should eat from 30
to 38 grams each and every day if you're
a woman
you should eat 21 to 25 grams each and
every day
if you're a child between the ages of
one and eight you should eat 14 to 31
grams
each and every day so what does the
research say
but first let's talk about where this
idea even came from
who had the bright idea that we should
eat lots of fiber
in our diets it actually comes from a
british surgeon by the name of dennis
burkett
and he was a very very intelligent
surgeon
there's actually a childhood cancer
burkitt's lymphoma
named after him he was very prominent
british surgeon
he practiced in africa for years and he
noticed that the african natives
who were his patients had these
ginormous poops several times a day
and he also noticed that they ate a lot
of fiber in their diet
and he also noticed that they didn't
have colon cancer
very often and they definitely didn't
have constipation
and they didn't really seem to have any
other bowel issues
and so he came up with this hypothesis
that eating a high fiber diet
should protect the human body from lots
of things including constipation and
colon cancer
so this idea literally came from an
impromptu
hunch that a single individual had
he did not do any control research he
did not do
any meaningful research on this
whatsoever he just
wrote a book about this and became known
as the fiber guy
and lectured all over the world and
since as i
mentioned earlier he was a very
prominent british surgeon
and he had done some very good work in
other areas people
tended to take what he said as gospel
one thing that you need to understand is
that these africans that he was studying
and practicing on
they also didn't need any added sugar
whatsoever and they also didn't eat any
highly processed grains and they also
didn't eat
any vegetable oils so there's that
he also had one other hypothesis which i
tend to agree with
uh he hypothesized that squatting is a
better
position to take a bowel movement in
than sitting and that it would help with
constipation and other bowel problems
now
i think that hasn't been proven either
but i think he may have been onto
something there
now let's talk quickly about what fiber
actually is
fiber is plant matter that our gut
absolutely cannot digest it
is well basically it's the same exact
thing as sawdust
or cardboard okay so uh
when you start looking at some of these
claims like it prevents
it it helps you lose weight well if i
took you
where you're at right now and i replaced
10 or 20
of your diet with sawdust and every day
we just mix sawdust into your oatmeal
and into your corn flakes
and so you were getting 10 to 20 more
fiber a day
fiber that your body cannot break down
cannot use as nutrition in any way
whatsoever
doesn't contribute any calories
carbohydrates protein fat to your diet
well duh yeah you're going to lose
weight because i'm feeding you something
you cannot use
is nutrition right this is also the way
it lowers your blood sugar
because however much of your diet you're
replacing
with fiber is giving you no nutritional
benefit at all including no
carbohydrates so of course your blood
sugar is going to come down
as for the claim that it improves heart
health or decreases your risk of heart
attack or stroke
again we're replacing 10 to 20 percent
of your diet with
sawdust or cardboard every day so you're
not able to eat
that much in volume of sugars and grains
and vegetable oils so we're basically by
putting 10 to 20 sawdust into your diet
you're not able to eat the things that
are actually increasing your risk of
heart attack and stroke
so yeah that kind of makes sense now
there is the argument
that gut bacteria living in your large
intestine
can break down this fiber and use it
and then somehow magically you derive
nutrition from that now it is true that
the
the bacteria in your gut can break down
this fiber and they can use it as fuel
because they can actually break the
cellulose down
but you cannot now there is some limited
evidence that the short chain fatty
acids that these bacteria produce
from eating the cardboard and the
sawdust
can move across the cell membrane of
your enterocytes which are the cells
that line your gut wall
and you're parasites probably do benefit
from these short
chain fatty acids a little bit but
that's not really nutrition for you
that's just those cells now
the truth is those cells get plenty of
short chain fatty acids from your
circulation
like your cells are supposed to get
nutrition from right
and there's very little evidence that
your entire body actually benefits
from these short chain fatty acids
whatsoever now
what these bacteria also make in
addition to the short chain fatty acids
is they also produce lots of greenhouse
gases
like methane and carbon dioxide and you
experience this
in the form of gas and farts and so by
eating a high fiber diet
are you actually contributing to global
warming
now let's look at the actual research
to support all these claims about fiber
so the weight loss claim with regards to
eating more fiber
has literally never been proven there
are some epidemiological studies that
show a possible
association but there is no control
research showing any causation
whatsoever
so mark that one off your list what
about preventing diabetes and lowering
blood sugar
well i talked about earlier how this
might happen if i made you eat twenty
percent of your diet as
cardboard well yeah you're not getting
any carbohydrates that you can use
so therefore your blood sugar is going
to come down and your you won't develop
diabetes
but that's kind of a weird way to
prevent diabetes and
surely there's a better way than that
what about improving your heart health
well uh there's literally no research
that's that's of a controlled fashion
that proves this or shows any
kind of causation it's all
epidemiological research
now the detox thing anybody anytime
anybody
on the planet says hey buy my product
and it will
detox your liver or your kidneys or
whatever
you can officially hit the unfollow
button right
there or the block button because that's
[ __ ]
okay if you want to detox any part of
your body
you fast that's how you do that that
it's cheap easy free
side effect free you never buy a product
to detox your body
what about the claim about constipation
eating more fiber helps with
constipation
anybody who has irritable bowel c or
chronic constipation or idiopathic
constipation they'll answer this
question for you anybody
who's tried to eat more fiber for
constipation put put in the comments
what your actual results were
because the results are always more gas
more bloating
maybe more constipation or diarrhea and
cramping
those are not solutions okay just
because you're putting more
roughage in that your body has to expel
as quickly as possible
that doesn't mean you're you're
meaningfully treating the constipation
there's actually a a very well done a
little study on this let me read you the
conclusion
this was a study done in 63 patients and
what they did was they gave them
different and they all suffered from
idiopathic constipation
and the researchers gave them different
amounts of
fiber and and one group they gave no
fiber and then they they kind of swapped
them around and kept playing with this
and here's their conclusion idiopathic
constipation and its associated symptoms
can be effectively reduced
by stopping or even lowering the intake
of dietary fiber so
there's a link down in the show notes if
you want to read the whole study it
i know really you're probably sitting
there going wait what
i thought what what yeah exactly so
fiber does not help in any meaningful
way with idiopathic constipation chronic
constipation
or ibs c
it doesn't help with any of those it's
going to make you have worse symptoms
the more you cut your fiber the better
your symptoms will be
now let's talk about colon cancer
because that's really once you've
narrowed some a pro fiber person down
this is the one they're always going to
cling to is that it decreases your risk
of colon cancer
so let's talk about a study and again
the links are down in the show notes
below so you can check this out for
yourself
it's a meta-analysis of five randomized
control
trials in humans that's important right
and so they they analyzed these five
different studies
that purported to well they had the
hypothesis that that eating more fiber
decreased your risk of colon cancer
here's the conclusion from this study
there is currently
no evidence from randomized controlled
trials to suggest that increased dietary
fiber intake
will reduce the incidence or recurrence
of adenomas polyps within a two to four
year period
adenominous polyps are the precursors of
colon cancer so
no evidence no rcts to even suggest this
okay now let's go to another study this
study was published in
the journal of the american medical
association it was a meta-analysis of
13 cohort studies very very large
studies
and after they crunched all the numbers
here's the conclusion they found
in this large pooled analysis dietary
fiber intake was inversely associated
with
risk of colorectal cancer in
age-adjusted analysis
however however that's an important word
after accounting for other dietary risks
high dietary fiber intake was not
associated
with a reduced risk of colorectal cancer
yep you heard me right so now let me
answer the question that was asked in
the title of this video
how much fiber do you need each day well
according to the randomized controlled
trials and the actual research on actual
human beings
you don't need any okay if you happen to
eat some fiber occasionally i don't
think it's dangerous or bad
it's probably not a big deal it may lead
to increased
gas bloating constipation diarrhea and
cramping if you eat too much
but do you need to try to get the the 21
to 38 grams that the american heart
association
recommends no you don't there's zero
research
reports supporting this so why did the
aha say this
i'm not sure maybe we should ask them in
a tweet the fda
said the same thing what research did
they base it on
none it is all based on an impromptu
hypothesis had by a very famous british
surgeon
decades ago and there has never been a
credible study
to show causation between fiber and any
of the things
that you will hear as potential benefits
for getting more fiber
in your diet therefore stop trying to
get fiber in your diet
if you're taking a fiber supplement
throw that crap in the garbage it's a
waste of money
if you're trying to eat high fiber foods
that you don't really like
stop doing that okay just eat more fatty
meat
you don't need fiber fiber's never been
proven to help you in any meaningful way
now your gut bacteria they appreciate it
when you eat fiber
and they make carbon dioxide and methane
to warm the
the atmosphere when you do so maybe
think
twice before taking another fiber
supplement or eating another high fiber
food
i sure hope this video has cleared up
some confusion you may have had about
fiber
in your diet if you haven't already done
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