Why is there still debate about whether intermittent fasting works
now many of you may remember it's been a long hard slog for docs that are way deep into the
science versus the docs that are just you know going through the motions every day
seeing as many patients as they can and writing prescriptions you know the right thing to do
is to understand the science and to spend time talking about the fact that lifestyle
is documented three times more effective than drugs surgeries supplements you can't
procedurize you can't stent you can't bypass you can't supplement you can't out-prescribe
a lifestyle problem and one of the major focuses on lifestyle the major focus far and away is diet
now there's a lot to diet and one of the things that has come up time and time again is this
concept of intermittent fasting in other words going through a cycle of fasting plus feeding as
you begin to look at that science to me it's just been piling up year after year after year that
it does help our body to go in cycles one of the terms that you hear when you hear the term
intermittent fasting most people basically on a practical basis mean skipping breakfast
there's a lot of other ways to do that it's actually more healthy if you can skip
dinner but again another way of looking at this daily intermittent fasting is time-restricted
eating TRE closing that eating window Valter Longo is one of the leaders in that space
so the day after Christmas everybody was still I think maybe most of us were overeating for the
holidays taking a little vacation the New England Journal the standard journal for the standard doc
it's going to be hard to argue with the New England Journal article at this point that
finally came out with a science review and so what it said was yeah it works it should become
a part of the standard of medicine for standard recommendations for lifestyle management so let's
get to exactly what that said preclinical studies clinical trials have shown that intermittent
fasting has broad spectrum benefits for many health conditions eating in a six-hour period
and fasting for 18 hours can trigger a metabolic switch from glucose-based to ketone-based energy
increase stress resistance increase longevity bring physical and cognitive effects benefits
decrease the incidence of diseases like cancer and obesity
in humans the three most widely studied intermittent fasting regimens are
alternate day fasting 5-2 intermittent fasting where you fast two days each week
and daily time-restricted eating now here's one of the images out of that article intermittent
fasting in the metabolic switch basically glucose and fatty acids are the major sources for energy
for ourselves after meals glucose is used for energy fat is stored in adipose or fat tissue
as triglycerides or fat during periods of fasting triglycerides are broken down
into fatty acids and glycerol which are used for energy fatty acids glycerol triglyceride
that's where it gets its name the liver then converts fatty acids into ketone bodies
which provide a major source of energy for many tissues especially the brain during fasting ketone
bodies are not just fuel used during periods of fasting they're potent signaling molecules with
major effects on cell and organ functions they regulate the expression and activity of many
proteins and molecules that are known to influence health and aging like NAD+ and sirtuins
and we're not going to go down that bunny hole right now of defining those we're going to assume
that you're familiar with those in other words biomarkers markers of metabolism ketone bodies
have profound effects on systemic metabolism by influencing these major cellular pathways
in the fed state not federal but having eaten fed state blood levels of ketone bodies are low
in humans they rise within eight to twelve hours after the onset of fasting benefits of
intermittent fasting due to the metabolic switch include improvements in glucose regulation blood
pressure heart rate efficacy of endurance training abdominal fat loss in other words
just a whole bunch of really good things so intermittent fasting and stress resistance
most if not all organ systems respond to IF in ways that enable the organism to tolerate and
overcome the challenge and then restore homeostasis in other words health a healthy
state cells respond to IF by engaging in a coordinated adaptive stress response that leads to
antioxidant defenses DNA repair protein quality control mitochondria biogenesis and autophagy
in other words cleaning up those mitochondria the powerhouse of the cell down regulation of
inflammation so decrease inflammation improved mitochondrial health improved protein quality
improved DNA antioxidant defense so a lot of really good things if stimulates autophagy
and mitophagy now wait a minute even if we know what autophagy is auto self phagy meaning to eat
the cell eating trash that it's created what is mitophagy mitophagy mito mitochondria so
what you're doing there with mitophagy is you're eating old beat up mitochondria while inhibiting
the MTOR remember that one mammalian target of rapamycin protein synthesis pathway we're
not going to go down that bunny trail either it's hard enough for me to keep on the straight
path here these responses enable cells to remove oxidatively damaged proteins and mitochondria and
recycle undamaged molecular constituents while temporarily reducing global protein synthesis
to conserve energy and molecular resources now intermittent fasting and aging after nearly a
century of research on caloric restriction in animals for example mice rats monkeys and humans
the overall conclusion was that reduced food intake robustly increases the lifespan in humans
IF ameliorates obesity insulin resistance dyslipidemia hypertension and inflammation
well if you improve all those items what do you think is going to happen to longevity in one
trial 16 healthy participants on alternate day fasting for 22 days lost two and a half percent
of their initial body weight and four percent of fat mass in other words they're losing more fat
with a 57% decrease in fasting insulin levels 57% decrease in fasting insulin that's a big deal
in two other trials overweight women were assigned to either a 5-2
IF regimen intermittent fasting regimen or a 25% reduction in daily caloric intake so
again we've got intermittent fasting versus caloric restriction the women in the two
groups lost the same amount of weight during the six-month period but in the group assigned
to the 5-2 intermittent fasting in other words fasting and then re-feeding fasting and re-feeding
those women had a greater increase in insulin sensitivity and a larger reduction in waist
circumference physical and cognitive effects of intermittent fasting in animals and humans
physical and cognitive effects or functions are improved with IF young men who fast daily
for 16 hours lose fat while maintaining muscle mass during two months of resistance training
in a clinical trial older adults on a short-term regimen of caloric restriction had improved verbal
memory in a study involving overweight adults with mild cognitive impairment 12 months of
caloric restriction led to improvements in verbal memory executive function and global cognition so
even caloric restriction appears to be having significant improvement with cognitive performance
in older adults now let's talk about obesity and diabetes on the island of Okinawa the traditional
population typically maintains an IF regimen fast intermittent fasting has low rates of obesity
low rates of diabetes and extreme longevity you remember read the book The Blue Zones or
just look it up on your computer or your iPhone the blue zones the architectural blue zone is
Okinawa what's another one Calabria Italy where Valter Longo was born
okay so members of the Caloric Restriction Society who follow the CRON Calorie Restriction with
Optimal Nutrition diet have low rates of diabetes with low rates of IGF-1 growth hormone and markers
of inflammation and oxidative stress wait a minute what's IGF-1 insulin-like growth
factor again these are all things that increase cell growth they also increase inflammation and
you get a decrease of that with both caloric restriction and with intermittent fasting how
about neurodegenerative disorders not so easy for me to say huh epidemiological data suggests that
excessive energy intake particularly in midlife increases the risk of stroke in other words
take in too much energy you way too much increase the risk of stroke Alzheimer's and Parkinson's
cancer a trial of daily caloric restriction in men with prostate cancer showed excellent
adherence 95 percent no adverse effects several case studies involving patients with glioblastoma
that's a very very aggressive brain cancer killed my grandfather on my mother's side it
also killed a fellow named Frank Polk who was the age researcher that I worked with at Johns Hopkins
several case studies involving patients with this suggest that
intermittent fasting can suppress tumor growth and extend survival cardiovascular disease
IF improves multiple indicators of cardiovascular health than animals and humans like blood pressure
resting heart rate HDL LDL triglycerides glucose and insulin in addition it reduces markers
of systemic inflammation and oxidative stress associated with atherosclerosis
the CALERIE Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy
CALERIE study showed that 12% reduction in daily calorie intake for two years improves
cardiovascular risk factors now why are we going through all these details that's all known right
as I said and here's a spoiler alert there was just an article recently that came out and said
maybe that's not true we'll talk about it in just a minute but let's just go into a little
bit more here so a diet of three meals with snacks every day is so ingrained in our culture
a change in this eating pattern will rarely be contemplated by patients or docs we need
to change that that's what the pro-IF guys like myself would say on switching to an IF regimen
many people will experience hunger irritability and a reduced ability to concentrate during
periods of food restriction however these initial side effects usually disappear within a month
and patients should be advised to this fact most physicians are not trained to prescribe
specific IF interventions physicians can advise patients gradually over a period of several months
reduce the time window during which the patients consume food each day with the goal of fasting
for 16 to 18 hours a day now here's so everybody's all happy finally moving in the right direction
with standardizing intermittent fasting and here comes this study on September 28th of this year
Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters in Women and Men
with Overweight and Obesity the TREAT randomized clinical trial in JAMA Internal Medicine and
here's the link if you want to look it up it was a 12-week randomized clinical trial including 116
participants 70 men 46 women 18 to 64 with BMIs between 27 and 43 participants were
randomized into consistent meal timing CMT group eating three structured meals per day or the TRE
group time-restricted eating group eat ad libitum you know eat whenever you want from 12 p.m to 8
p.m and completely abstain from 8 p.m to 12 p.m the following day the primary outcome that they
looked for was weight loss secondary outcomes were the things that we've been talking about
changes in weight fat mass lean mass fasting insulin fasting glucose A1c levels estimated
energy intake in other words how much total food are you eating total energy expenditure resting
energy expenditure now as you notice there's not a whole lot about other markers like IGF-1 and that
sort of thing the conclusions on this study were TRE did not confer weight loss or cardiometabolic
benefits and TRE was associated with a moderate decrease in weight but it was not significantly
different from the decrease in the control group what the heck are we supposed to make of that
continue to get great feedback regarding the webinars and here's why you know on the
Internet when you hear a webinar you expect for somebody to try to sell you something we're not
doing that we're trying to tell you something people are coming in with their labs from Quest
inflammation panel OGTT insulin survey response and then they're finding out do
I have inflammation do I have insulin resistance and where does that fit in terms of other folks
we're getting ready to start one for CIMT as well so again people are really excited about finding
out their own status looking forward to seeing you there thanks continue to get great feedback
regarding the webinars and here's why you know on the internet when you hear a webinar you expect
for somebody to try to sell you something we're not doing that we're trying to tell you something
people are coming in with their labs from Quest inflammation panel OGTT insulin survey response and
then they're finding out do I have inflammation do I have insulin resistance and where does that
fit in terms of other folks we're getting ready to start one for CIMT as well so again people
are really excited about finding out their own status looking forward to seeing you there thanks