no documentario culpam o consumo de proteinas, aconselho a terem cuidado pois os cientistas estao sempre a inventar teorias da treta contra o consumo de carne
aqui fica outro ponto de vista (bem mais realista)
▪ IGF (insulin-like growth factor): a growth factor that can mimic the effects of
insulin. Acts locally, and concentrations change slowly over days or weeks,
reflecting long-term food supply.
▪ likely the key player in cancer; shutting down IGF receptors strongly (if
not totally) suppresses tumor growth
▪ IGF is mostly bound to proteins in the bloodstream, and inactive; only a
small percentage is unbound and active
▪ insulin reduces the amount of binding proteins, freeing up more
IGF
▪ carbs raise insulin, which raises IGF, which promotes cancer
▪ tumor cells have 2-3 times as many IGF receptors
▪ IGF may even inhibit or override the programmed cell death mechanism
(fail-safe mechanism to prevent damaged cells from multiplying)
▪ extra insulin receptors provide the extra glucose for fuel, extra IGF receptors
provide the strong stimulus to proliferate.
▪ cancer is caused by the internal conditions that nurture cancerous
cells (not by mutations, which are inevitable)
▪ problem is with the endocrine and growth factor environment, not
"carcinogens"
• Longevity
◦ caloric restriction dramatically increases the lifespans of rodents, worms, fruit flies, and
more
▪ not because they have less fat or weigh less — genetically obese mice live as long
as normal lean mice when both are calorie restricted (even though they're 4 times
fatter)
▪ longevity correlates with food consumption, not the degree of adiposity
▪ caloric restriction reduces oxidative stress (from free radicals), but this is only a
secondary phenomena
◦ insulin and IGF: primary role in longevity
▪ long-lived organisms in the lab (due to caloric restriction) all have reduced insulin
resistance; very low blood sugar, insulin and IGF.
▪ low blood sugar also means less AGE formation
▪ genetic studies have found that mutations to the genes that control insulin
and IGF signaling bestow extreme longevity
▪ insulin and IGF respond to food availability, regulating metabolism, fat storage,
and reproduction
▪ IGF regulates cell division and growth; insulin regulates metabolism by
partitioning fuel for use or storage
▪ longevity implications: when food is abundant, insulin and IGF
activity increases and stimulates growth, maturity and
reproduction; when food is scarce, such activity is reduced and
long-term survival is favored over immediate reproduction.
▪ evolutionary logic: if food is abundant, organisms can successfully
multiply; if food is scarce, reproduction will be useless as parent
and offspring will die of starvation. The food-sensing mechanism
extends lifespan to increase the chances of being alive and fertile
when food returns.
▪ Cynthia Kenyon found that feeding worms glucose shortened their lives
▪ she personally went low-carb with great results: weight loss; lower blood
pressure, trigs, and blood sugar; HDL increased
◦ the mainstream accepts the insulin-IGF research, but avoids any possible dietary
implications, instead focusing solely on drug or gene therapies
▪ another common approach accepts the insulin-disease connection, but then
assumes that hyperinsulinemia is caused by insulin resistance which is caused by a
