A WebMD Health piece on the Fast Mimicking Diet (FMD),
written awhile back for a “consumer audience,” was, I thought, a little too “thin”
(in substance). The research paper referenced in Cell,
however, was a little too “thick.” Still, it was interesting, so I wrote about
it here
in #382, “Can fasting ‘wake-up’ the pancreas?”
My editor thought I could do better, though, so she
sent me this BBC piece, “Behind
the Headlines – Health News from NHS Choices.” This time the porridge was neither
“too thin” nor “too thick.” I was just right!
The BBC lede jumps right to the conclusion: “‘The
pancreas can be triggered to regenerate itself through a type of fasting diet,
say US researchers.” Pithy, hey what? Here are key excerpts, for your
elucidation:
“Mice were fed for four days on a low-calorie,
low-protein and low-carbohydrate but high-fat diet, receiving half their normal
daily calorie intake on day one, followed by three days of 10% of their normal
calorie intake.”
“Researchers repeated this fast on three occasions
with 10 days of re-feeding in between to ensure they regained their body weight
before the next fasting cycle.”
“They then examined the pancreas. They found in mice
modeled to have both type 1 and type 2 diabetes, insulin production was
restored, insulin resistance was reduced, and beta cells could be regenerated.”
“Researchers also recruited healthy human adult volunteers
without a history of diabetes, who underwent three cycles of a similar four-day
fasting regimen. Their blood samples were applied to the cultured pancreatic
human cells. The results in the human cell samples suggested similar findings
to those seen in mice.”
The BBC summed it up: “The researchers concluded that,
‘These results indicate that an FMD promotes the reprogramming of pancreatic
cells to restore insulin generation in islets from T1D patients and reverse
both T1D and T2D phenotypes in mouse models.’” “This is good science,” a
professor at Cambridge commented.
The Fast Mimicking Diet (FMD) employed in the study
and reported on in Cell was conducted
at the University of Southern California (USC) and the Koch Institute at MIT,
plus in Italy. It was funded by grants from the US National Institutes of
Health and the US National Institute on Aging. It was high fat, low carb, low
protein and, okay, very low calorie, especially in the last 3 of the 4 days. In
that sense, it “mimics” a “water-only” fast; that is, the biomarkers had the
same physiological effects on the body as the more extreme “water only” fast.
The FMD is a way to eat that tricks the body into
thinking that a person is fasting. The 3 salient biomarkers that the body
produces are 1) lower levels of IGF-1, a hormone with a molecular structure
similar to insulin, 2) lower levels of glucose and 3) an increase in ketone
bodies. The hypothesis is that a more
extreme “water-only” fast would produce the same effects, but is unnecessary if
you’re unwilling to go there, yet.
The effect of the HIGH FAT, LOW CARB and LOW PROTEIN
FMD used in the USC/MIT study on mice and men was to “reboot” the pancreas to help
the insulin-producing cells repair themselves and start producing the hormone
(insulin) again. The study in Cell
said, “During periods of fasting, the cells go into ‘standby’ mode. When
feeding begins again, new cells are produced that have the potential to become
insulin-producing.”
From
an evolutionary standpoint, the ability of animals to survive food deprivation
is an adaptive response accompanied by the atrophy of many tissues to minimize
energy expenditure. Thus periodic cycles of fasting, leading to the oxidation
of pancreatic fat cells, the removal of impaired tissue (autophagy) and the death
of other cells by apoptosis (pre-programmed death), “induced by the stepwise
expression of certain genes,” are regulators of cell metabolism which enable
the pancreas to reprogram itself to restore insulin production and regenerate
stem cells similar to those observed during pancreatic development. Might FMD be
worth a try?
So does the FMD also accomplish the other things that fasting does: reducing fat in the organs themselves (liver, etc) which in turn reduces/maybe cures insulin resistance?
ReplyDeleteThe way I read it, the answer is "yes" to the first part of your question, but "not addressed" to the second part. Type 2 diabetes has 2 components: The IR at the cellular receptor part of glucose uptake, and the blocked (or destroyed) ability of the islets to make insulin in the beta cells. These findings address the second (pancreatic) part but do not appear to address the IR part. Remember, the IR comes before the pancreas is asked to make more insulin and eventually is unable to because the beta cells are killed (or blocked by fat cells in the pancreas). But if the ability to make beta cells is restored by the FMD, that does not address the damage to the insulin receptors at the cellular glucose uptake level.
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