Dr. Stephen Phinney on the Safety and Benefits of a Ketogenic Diet (Part 2)
– Nutritional ketosis
is a very powerful tool. And it can be used to achieve metabolic health and
well-being in people who have diseases associated with insulin
resistance or inflammation. Now, there are lots of
myths and misunderstandings about ketogenic diets and
about nutritional ketosis and I wanna really focus
on the scientific evidence around safety and efficacy of
this approach to nutrition. And I realize it's hard
for people to commit to this kind of endeavor if
people around you are saying, "Oh, this is dangerous so
you shouldn't be doing it." So you need to be confident
that if you undertake this that you're doing it in a
safe and efficacious way. In study after study,
not just ours but others, a well-formulated ketogenic
diet when compared to a standard calorie
restricted low fat diet has a greater effect on weight loss and particularly loss of
abdominal adipose tissue and it's the adipose tissue or
a fat mass within the abdomen that is the most dangerous
fat that we carry in our body.
For instance, a study that
I did with Dr. Jeff Volek and Dr. Cassandra Forsythe,
one of his graduate students, we compared a high carbohydrate low-fat calorie restricted diet
to a ketogenic diet that people followed
where their instruction was to eat to satiety,
that is not count calories and don't restrict calories but eat enough to feel like they had had enough food and they weren't hungry. And we ran the study for 12 weeks. And at the end of 12
weeks, the weight loss in the high carbohydrate
low-fat group was about half the weight loss in the
ketogenic diet group. Now, some critics will
say that well, when you go into ketogenic diet, a lot
of your weight loss is water. But we actually did careful
measurements of body fat and the water loss on the ketogenic diet was only about 1/5 of the difference so five kilograms on the
carbohydrate rich low-fat diet and 10 kilograms on the ketogenic diet and only about 1/5 of
that difference was water, the rest was body fat.
More importantly, we used
the dual x-ray absorptiometry so called DEXA technique to
measure body fat content. There is a significantly greater reduction in abdominal fat, so
it's not just total fat, it's not fat from under the skin, but it's some of the most dangerous fat is more rapidly mobilized
when someone gets the ketogenic diet right. The next most common effect is for people who have either slightly
or markedly elevated blood glucose levels, so
either prediabetes or diabetes, a prompt response of the ketogenic diet is a reduction in blood glucose.
Now, that makes sense because
if you eat less carbohydrate in a diet, there's
going to be less glucose produced by digestion and
the level of sugar coming into the blood is gonna be reduced, that's what we commonly see. However, in Dr. Forsythe’s study… Now, these are people with prediabetes but their blood sugars are
still slightly elevated. We saw a marked reduction in blood glucose in the people on the ketogenic diet and no change in blood
glucose in the people who were on the high
carbohydrate low-fat diet.
What's more interesting
is that we also measured blood insulin levels. And insulin's a hormone that
makes glucose go into cells, so if the blood sugar
came down, you'd think that the body was making more insulin to make it go into the cells. But it was the opposite of what we saw. And that is that insulin
level came down dramatically, blood glucose came down. And the only way you can
make sense out of that is that the ketogenic diet
improved insulin sensitivity, that is the body's response
to any one molecule of insulin is markedly greater. And that's a consistent finding we've seen across multiple studies and that's the finding that
has let us to the concept that we can actually
reverse the root cause of Type 2 diabetes. Another effect of a
well-formulated ketogenic diet is to change the blood lipid values that are characteristic
of metabolic syndrome.
And, by the way, metabolic
syndrome is also referred to as prediabetes. Typically we'd see with metabolic syndrome a reduced good cholesterol,
an increase in triglycerides and a greater proportion
of the small dense or bad LDL cholesterol. And when we looked at that in this cohort, we saw that triglycerides plummeted. Now, they went down in both groups but they went down more than twice as much in the patients on the ketogenic diet.
And by they way, they
were eating more fat, and yet the blood fat levels dropped. HDL went up about 13% which is greater than any
HDL response we can get from any drugs that we have available, that we can write as a prescription. So this is a pretty much unique benefit to a well-formulated ketogenic diet. And then the small dense LDL which are the most dangerous didn't go down. If anything they went
down slightly in the group who were eating the high carb low-fat diet and went down sharply in the group on the ketogenic diet.
So again, all the lipid changes are going in the right direction in
favor of the ketogenic diet. So again, the concern about
eating a high fat diet, eating maybe eggs and meat and dairy which contains cholesterol, the actual, the cholesterol in the blood and the blood lipids are
changing all in a beneficial way when one gets this diet right. If you're eating low carbohydrate
and moderate protein, the majority of your dietary
calories come from fat. And a lot of the fats
that people eat typically come from animal products or from dairy and cocoa butter and things,
which are saturated fats.
And so the question is is
eating a lot of saturated fat dangerous when you're on a ketogenic diet? And the reason people
propose it as dangerous is that we know that when
you measure blood levels of saturated fat, that
the higher the blood level of saturated fat, the
greater the risk of diabetes, a heart attack and overall mortality. And so if you assume that
eating saturated makes makes the blood level go up, that would suggest this is dangerous. But people hadn't ever
actually looked at what happens to the blood levels with saturated fat when they're going to
ketogenic diet, so we did. And what we found was,
even though, the people on the high fat diet, the ketogenic diet were eating three times as
many grams of saturated fat per day, their blood
levels of saturated fat actually were lower than the group eating the lower saturated
fat intake high carb diet.
And again, this is a head scratcher. It appears that we've disconnected intake from blood levels. And that violates the law
that all dietitians tell you that you are what you eat. In actuality, you are what
you save from what you eat. And the neat thing
about the ketogenic diet is it teaches your body to
burn fat more effectively. How effectively? Well, we did a study where we looked at highly trained athletes
some of whom were following a traditional high carbohydrate
loading diet regimen and the other half of them were following a well-formulated ketogenic diet. And these people had been
following these diets for at least six months or longer, which means that they
were fully keto-adapted for the ones on the low
carbohydrate or ketogenic diet. And when we looked at the resting rate of fat oxidation, it was about double as much on the low carbohydrate ketogenic diet as it was on the high carbohydrate diet.
So again, highly trained
athletes, theoretically, their bodies are highly
conditioned to burn fat for fuel during exercise and yet,
just the difference of diet doubled the bodies' ability
to burn fat for fuel. And then as they… We had them do greater and
greater levels of exercise, the people on the
ketogenic diet demonstrated remarkable ability to use fat for fuel. The athletes like that
because they can run on body fat stores much
better than trying to eat and load with carbohydrate which means that when you're keto-adapted, your body has a capability of
getting rid of saturated fat and so the amount you
eat is not important, it's how much your body
saves from what you eat. And clearly, the body
doesn't save saturated fat when you're keto-adapted, which means that saturated
fats are not harmful when consumed, if you're keto-adapted.
Another very important
area of current research is in the topic of
inflammation because we know that when we measure
biomarkers of inflammation, and there have been
some that we've measured over the last century,
like white blood cell count and some that are more
recent additions to our ways of measuring inflammation. That those levels predict
the later onset of diseases like heart disease, Type 2 diabetes, Alzheimer's disease and many
of the common forms of cancer. And so in doing the study
with Dr. Volek and Forsythe, we actually measured every
biomarker we could think of and we came up with 14 different
biomarkers of inflammation. And when we compared them for the people in the high carb diet
versus people adapted to the low carb high fat diet, none of the levels of
inflammation went down more in the people who were on
the high carb low fat diet. In contrast, 7 of those 14
were significantly reduced for the people on the
well-formulated ketogenic diet. That is on average there
was a marked reduction in inflammation with the
ketogenic diet, indicating that this has a wide-ranging
antiinflammatory effect.
Now, up until recently,
that's been what we scientists call a phenomenon. We see it's happening
but we don't know why. And it turns out that
there is a particular gene, it's kind of like a traffic cop gene, it regulates the flow of
traffic around inflammation. And this gene is targeted
directly by the ketone that we have circulating… A primary ketone in our blood which is called β-hydroxybutyrate, or BHB. And this is a place where
ketones talk to your genes and your genes turn down
the heat, if you will, through a regulated series of events to reduce inflammation of the body and that has the likelihood of
having very positive effects not just on reducing insulin resistance but also reducing other common
chronic diseases, as well.
Now we not only know that
the inflammation goes down, but we know why it goes down
and why it is so effective and even modest levels
of ketones, the levels that you achieve just by
restricting carbohydrates to less than 5% of total calories
and keeping protein moderate. We're doing a study with
Indiana University Health where we recruited over 260
people with Type 2 diabetes and put them on a
well-formulated ketogenic diet. This study will be going on for two years, but I want to show you just the early data from the first 10 weeks of the study. All these people had the
diagnosis of Type 2 diabetes. Some were poorly controlled, some were pretty well controlled, some were very tightly controlled. So we divided the biomarker
of diabetes control called hemoglobin A1c or HBA1c into high levels, intermediate levels and well controlled levels. And in all three cases, after 10 weeks, there was a reduction in
the level of hemoglobin A1c and this effect was greatest in the people who had the highest levels. So people who had the poorest
control of their diabetes got the greatest effect, but
all three groups had an effect.
And the result was that over
half of these people moved from having hemoglobin A1c
levels in the diabetes range into the non-diabetes range. What's really intriguing is normally in medical care diabetes, you
get better glucose control by giving people more drugs. In this case, we took
away most of the drugs from five of the seven classes
of diabetes medications. And the two most dangerous which are insulin and sulfonylurea, those are the two classes of drugs that are most likely to cause hypoglycemia which is probably the most
threatening side effect, short-term side effect
of in diabetes management that we either stopped or markedly reduced the majority of those
medicines in these patients. And so here, again, we have the paradox, less medication, better control. And the reason we can get better control with less medication is β-hydroxybutyrate in ketones, in general, speak to the genes and
change fundamentally how the body functions,
including changing how the body responds to insulin so the body
can get much greater benefit from far less insulin.
And then as a side effect of this, again, we told people to eat to satiety. It limited carbs, protein in moderation, as much fat as they needed, and again, they can put butter on their meat, they can put butter or
dressing on their vegetables and dip with vegetables, things like that. And so they were eating to satiety, and yet 75% of these patients lost more than 5% of their body weight. And on average, the body weight loss was as a little bit over 7%. And that was just in the first 10 weeks. At six months in this cohort, the weight loss went from 7% to 12%. So this is not a short-term
quick loss and then regain, but it appears to be a
sustained long-term effect.
Because, again, people who
are six months into our study are doing the same thing we
told them to do at the onset and that is limit carbohydrate,
protein in moderation, eat fat to satiety and that
gives the body permission to burn a lot of body fat
stores because the body has become so efficient
in burning fat for fuel. Just to mention other
conditions that we've seen that show improvement
with the ketogenic diet, just general muscle and
join aches and pains. Irritable bowel syndrome
typically gets better.
Polycystic ovary syndrome in women. People with migraine, headaches mention that either their frequency is down, the intensity is down and some
people get complete remission of their migraines when they
get the ketogenic diet right. As we showed from the
study of Dr. Forsythe, metabolic syndrome or
prediabetes has improved along with that liver fat levels go down which is a side effect of
poorly controlled diabetes. And we see improvements in fluid retention and blood pressure, as well. This is a very powerful tool. It can have very beneficial effects on a number of chronic conditions, but when a person's taking medicines for these chronic conditions, those beneficial effects usually mandate a sharp and rapid reduction in medication.
And that can be dangerous,
unless you have the assistance of a physician who
understands this type of diet and understands how to
manage the medications. This cannot be done in a casual way, you can't start a diet and go
back and see your physician six weeks later and say, "So
what do you think I should do with my diabetes medication?" Because typically we
have most of the changes in the first six days when
people get the diet right. The concern is finding a
doctor who understands this and that is sometimes difficult, but we see increasing
interest in physicians, so if you look carefully,
you can probably find someone who can help you, if you
need that kind of assistance when you're following
this type of regimen. So again, for our conclusion is a well formulated diet is not only safe but it can be very effective
in reversing disease. These effects are so powerful. However, this has to be started
with careful monitoring. Stated in this directly,
you have to find a physician who can help you manage your medications in the proper way that this
be done where the benefits far outweigh any potential risks involving changes in medication use.
