You know the feeling you get when you learn something new
about a health problem you’ve been trying to reverse?
Maybe high blood pressure, diabetes, or heart disease.
Well, there’s nothing I like better than bringing you the information
that will help you do just that.
Welcome to the Nutrition Facts Podcast.
I’m your host, Dr. Michael Greger.
Today we discover the mighty power of oatmeal.
Did you know that before there was insulin,
there was the ‘oatmeal cure’?
The life of many diabetics was saved
or prolonged by Carl von Noorden’s oatmeal diet,
which he apparently stumbled upon accidentally.
Some of his diabetic patients had gastrointestinal issues;
so, he put them on oatmeal,
and instead of the sugars spilling over into their urine
getting worse, they started getting better.
He published his findings in 1903, which was received
with a great deal of skepticism.
But the skeptics were overcome, however, in the following years
by the weight of the evidence.
A turning point came when a doctor
as notable as James B. Herrick gave it a try.
Dr. Herrick is acclaimed for his description of sickle cell anemia,
which was originally known as Herrick's syndrome.
When Dr. Herrick began to try out the oatmeal diet on his patients,
he was very skeptical, but was astonished by the results.
Intense skepticism was how Herrick put it.
His first experience in prescribing it
was far from encouraging.
After taking one or two meals, the patient said,
“Doctor, I will die before I taste another spoonful of that oatmeal mush.”
And indeed, tragically, she did.
Other doctors echoed patient reticence
to tolerate so monotonous an equine diet.
But in general, Herrick said,
he went on to experience little difficulty
in putting patients on the oatmeal diet
and in keeping them there for a few weeks.
And nothing, he reported, was more surprising
or more gratifying than the salutary effects he witnessed
of the oatmeal diet in diabetes of the young,
leading to the 1909 proclamation that no case of juvenile
or adolescent diabetes should be deprived
of the benefits of the oatmeal cure.
The great Elliott Joslin, founder of the oldest
and largest diabetes clinic in the world,
described the effects of the oatmeal as sometimes magical,
describing the oatmeal cure as an unsolved mystery,
referred to back then as one
of the greatest puzzles in diabetes.
They did have some clues though.
They found that animal protein had to be strictly excluded,
as it annihilates the favorable action of oatmeal-type diets.
They used to use eggs with the oatmeal diet,
but they got better results without them.
And now we know, over a century later that indeed,
animal protein intake intensiﬁes insulin resistance,
which is the cause of prediabetes and type 2 diabetes,
whereas plant-based foods enhance insulin sensitivity,
which is the opposite.
Animal-protein intake is not just associated
with insulin resistance and a clear association
with an increased risk of type 2 diabetes
(and this included animal protein from meat, dairy, and ﬁsh—
higher insulin resistance and risk of prediabetes and type 2 diabetes).
But not just an association; you can put it to the test.
Swapping in beans for beef improves cardiometabolic risk factors.
And it doesn’t take much.
Replace just two servings of red meat with lentils, chickpeas,
split peas, or beans a few days a week,
and you can significantly improve fasting blood sugars and insulin levels,
along with the improvements you’d expect,
like lowering of cholesterol and triglycerides.
Based on over a dozen randomized controlled trials,
even just swapping like a third of protein
from animal to plant sources
can significantly improve blood sugar control.
What’s the difference
between animal protein and plant protein?
We think it’s the branched-chain amino acids
concentrated in animal protein.
How do we know branched-chain amino acids are playing a role?
Because if you give vegans branched-chain amino acid supplements,
you can make them as insulin resistant as meat eaters.
Their insulin sensitivity dropped to the level resembling omnivores
and only improved again after stopping the supplements.
But wait a second.
I thought insulin resistance stems from excess accumulation of fat
inside your muscle cells, particularly saturated fat.
Insulin resistance directly correlates
with increased saturated fat inside your muscles.
I’ve got tons of videos on this,
but basically you can show a substantial
and consistent impairment of insulin action,
substantial and consistent insulin resistance
after just a single day
consuming a diet high in saturated fat.
In fact, even a single meal rich in saturated fat
reduces insulin sensitivity.
A single dose of butter, for example,
impairs insulin sensitivity even in healthy subjects.
And over time, reducing cholesterol
and fat intake may even enhance the ability of your pancreas
to pump out insulin in the first place.
Now, the saturated fat getting lodged in your muscles
may come from the foods going into your mouth,
or if you have excess abdominal fat,
from previous meals spilling over into your blood stream.
But either way, what does animal protein have to do with it?
It turns out a branched-chain amino acid breakdown product
appears to stimulate fat uptake
and accumulation inside the muscle cells.
But oatmeal doesn’t have any saturated animal fat or animal protein.
Okay, but neither does any plant food.
Why might oatmeal work particularly well?
That’s the question I explore next.
It is now widely accepted that diets high in animal fat
and processed foods are an important risk factor
for development of type 2 diabetes.
And it’s not just animal fat, but animal protein intake
intensiﬁes insulin resistance,
which predisposes people to type 2 diabetes.
No wonder studies have shown that elevated consumption
of animal products and low intake of unprocessed plant foods
increases the risk of not only cardiovascular disease but diabetes.
But of all the whole plant foods to pick, why choose oatmeal
to treat diabetes, which, as I discussed in my last video,
was used for the treatment of diabetes before insulin was discovered.
We’ve long known that higher consumption of whole grains, including oats,
is associated with a lower risk of diabetes, but you don’t know...
until you put it to the test.
There have been over a dozen randomized controlled trials
looking at the metabolic effects
of oats intake in patients with type 2 diabetes,
and oats were found to significantly improve
both short-term blood sugar control and long-term blood sugar control
in addition to lowering cholesterol levels.
We think the benefits arise from a fermentable ﬁber in oats
called beta glucan, because you can get cholesterol-lowering
even if you just give the oat fiber straight,
as well as an improvement in blood sugar control
and insulin sensitivity in both type 2 diabetics,
as well as type 1 diabetics.
How exactly does the fiber do that?
Well, we know one of the underlying cholesterol-lowering mechanisms
of oatmeal consumption might be its microbiome-manipulating ability,
in other words, having a beneficial effect
on our intestinal bacteria.
The anti-inflammatory effects of the short-chain fatty acids
that our good gut flora make from fiber.
There are dozens of randomized controlled trials
showing the types of fiber found in oats
and beans can improve long-term blood sugar control in diabetics—
in fact, nearly double the FDA threshold
required for new blood sugar- lowering drugs. Why?
Because the gut bacteria selectively promoted by dietary fiber intake
can help alleviate type 2 diabetes.
In fact, on the basis of 50 distinct bacterial markers of the feces,
you can tell who does and does not have diabetes.
But change your diet, and you can change
your gut flora within one day.
We feed them with fiber, and in return,
they feed us right back with these short-chain fatty acids
like butyrate that have all these wonderful effects.
Put people on a diet packed with oats, beans, fruits, vegetables, and nuts,
and the number of fiber-feeders
churning out the beneficial short- chain fatty acids shoots up,
and fasting diabetic blood sugars drop about 25 percent within one month.
And the more fiber- feeders they fostered,
the better their blood sugar control.
When the fiber-promoted short-chain fatty acid producers
were present in greater diversity and abundance,
participants had better improvement in their hemoglobin A1c levels
(which is a measure of longer-term blood sugar control).
Then, before and after fecal transplant studies
helped nail down cause and effect.
The oat fiber itself has been shown to act as a prebiotic,
boosting the growth of beneficial bacteria
like lactobacillus and bifidobacteria.
So, between the lack of animal protein,
lack of animal fat,
and bursting at the seams with prebiotic fiber,
it’s no wonder that oatmeal diets grew to become
part of the clinical routine in the treatment of diabetics.
However, over time, this practice
has later become increasingly forgotten,
a disappearance that’s been compared to the fate
of unpopular theories in successive editions
of Soviet encyclopedias.
Despite advances in therapy, we still have many people
with poorly controlled diabetes.
Thankfully this forgotten tool is back.
I’ll review all the new oatmeal diet studies next.
Thousands of years ago in ancient Egypt, diabetes was described
as a “too great emptying of urine” or, more poetically,
as being “like the River Nile between the thighs.”
The recommended remedy, ironically, was a diet
consisting of wheat grains, grapes, honey, and berries.
The guy who coined the term “diabetes” about 500 years later
also prescribed a high-carbohydrate diet.
Then, right up until we had insulin,
doctors were saving the lives of diabetics with an oatmeal diet.
This wouldn’t make any sense until Sir Harold Himsworth arrived
on the scene, the first to separate out type 1 diabetes
from type 2 diabetes and define this concept of insulin resistance.
After just a few days on a high-fat diet,
you can get twice the blood sugar spike in response
to drinking sugar water,
compared to after eating a high-carb diet.
Now that type 2 diabetes is like the Black Death of the 21st century
in terms of devastating health impacts,
what about revisiting the almost forgotten,
short-term dietary oatmeal intervention as an economical,
yet—spoiler alert— highly effective tool to achieve
better blood sugar control in patients with type 2 diabetes?
Basically, patients are offered up to about
two and a half cups of oatmeal three times a day
as their meals with nothing but some herbs
and maybe small amounts of raw vegetables just to mix things up.
For how long? Just a couple of days.
Note that’s only like a thousand calories;
so, the result is a hypocaloric, plant-based dietary intervention
that is low in fat—in fact, no added fat—no salt,
and excludes animal protein.
Is a few days of oatmeal really going
to make much of a difference?
Check out this case report of an oatmeal intervention
for severe insulin resistance in the ICU.
Within 48 hours of admission, the patient developed
such severe insulin resistance she required
more than 200 units of insulin per day.
Up until then, the patient received standard diabetic tube feeds,
which obviously were not working.
So instead, they dropped oatmeal and vegetables down the tube instead,
presumably using a really good blender.
And lo and behold, it worked.
But you've got to see the numbers.
Yeah, her first blood sugars of the day dropped
from up around 250 down to about 100 five days later.
But that near-normal blood sugar was on 160 fewer units of insulin,
down from over 200 units a day.
Lower blood sugars on 160 fewer units of insulin!
Okay, I can see how if you’re trying to save a life in the ICU,
an oatmeal diet can be near-miraculous.
But just in regular diabetics,
what good is eating oatmeal for a few days
if you just go back to your regular diet?
Several studies have suggested that the beneficial effects
could last like a month after the few days of oatmeal.
For example, in this randomized controlled crossover trial
not only did insulin needs drop about 40 percent in just two days
compared to just restricting calories alone
with a hypocaloric diabetic diet,
but also a measure long-term blood sugar control
taken four weeks later reflected the benefit.
So, we’re talking a highly significant reduction
of required daily insulin doses
with beneficial effects shown weeks later.
Who cares if you have to take huge doses of insulin though?
Because insulin causes weight gain,
which just makes the underlying insulin resistance worse.
So, it’s like this vicious cycle.
But instead, with the oatmeal you’re actually treating the cause,
not to mention the incidence of cancer and overall mortality
associated with having such high levels of insulin
in your body all the time.
Other new studies have shown the same thing.
Two days of oatmeal significantly reducing the required amount
of insulin and improved blood sugar levels
with beneficial effects noted for up to four weeks.
For example, here.
Patients with uncontrolled type 2 diabetes,
with the two-day oatmeal diet
leading to a 40 percent reduction of insulin dose,
accompanied with almost normalization of average blood sugars.
Although the intervention only lasted for two days,
they observed a lasting significant reduction of insulin dosage
and ameliorated mean blood sugars for weeks
after they were dismissed from the study.
And this was after they resumed their regular diets.
Look at this. A massive drop in insulin needs
after the oatmeal for two days, but look, a month later
they were still needing like 40 percent less insulin.
Wait a second. How could this short intervention lead
to such dramatic results that somehow continue on for weeks?
Although short-term dietary oatmeal interventions
cannot be compared to whole food, plant-based diets
in terms of maximizing the intake of protective foods—
I mean that’s ideally what people should try to eat
to reverse their type 2 diabetes completely—
but they both strictly exclude the animal-based foods
that seem to increase the risk of developing diabetes.
So, even cutting out saturated fat for like two days
may so reduce insulin resistance you can free ride
on that for at least a few weeks, even if you go back to eating crap.
WARNING, though. If you try this oatmeal diet,
your physician has to be ready to rapidly deprescribe
your blood sugar drugs else you become dangerously overmedicated.
Imagine if this woman was still getting 200 units of insulin.
Her sugars would crash so low she’d be dead.
So, oatmeal interventions should not be performed
in patients that might have difficulties
in reporting symptoms of low blood sugars,
who you can’t closely monitor.
So, the downside of trying oatmeal days
is that it may work a little too well;
so, it must be done under close medical supervision.
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Go to nutritionfacts.org/testimonials.
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To see any graphs, charts, graphics, images, or studies mentioned here,
please go to the Nutrition Facts Podcast landing page.
There you’ll find all the detailed information you need –
plus, links to all of the sources we cite for each of these topics.
My last two books are “How to Survive a Pandemic”
and the “How Not to Diet Cookbook”.
Stay tuned for December 5, 2023
for the launch of my new one, How Not to Age.
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