Stumbled upon this Tedx talk by Mark Mattson during my searches on IF, low carb, and health:

http://tedxtalks.ted.com/video/Why-...ters-Brain-Powe

In getting some background on Mark, the more I learned, the more impressed I became:

https://en.m.wikipedia.org/wiki/Mark_Mattson

Some of this information will be familiar:



He's an active scientist who is making meaningful strides in health research that perpetuates the theme of food and its regulation as a superior prescription.

http://www.sciencedirect.com/scienc...550413113005032


I highlighted the portion in bold, as it brought to mind some of our threads that discussed IF and calorie restriction. I've often wondered what kind of role protein might play, and might its absence be the key during IF and the resulting positive impacts on insulin, BG, and cellular repair. While protein is essential, its periodic absence appears to be an enabling factor in metabolic healing.

Very interesting, I wonder why the restriction of essential amino acids would reduce IGF-1. Would a fat fast be almost as effective in dropping glucose, insulin and IGF-1?


How about not eat a diet of fat and glucose, supplemented with high-fructose corn syrup? Were they trying to replicate the SAD?, because this sounds like a good approximation.

Very nice TED talk. I'm speed reading the 1911 Upton Sinclair book right now that was mentioned.

https://books.google.com/books?id=j...epage&q&f=false

Oddly I've just started a three day fast after several weeks of 24 hours tuesday and Thursday jobs. I duno, I find it very difficult to limit my calories to 500 when doing these short fasts. Sinclair says fasting is easier after 2- 3 days and he would never do short fasts as the hunger gets in the way.

Agree on the short fast observation. I find that a 3-day or longer fast is easier, as I have no hunger after the first day, and on day 3 feel that I could go much longer if I wanted. At some point early in the new year, I'll try a 5-day fast.

Thanks for the link. I'm into the book now.

Good question, as the absence of protein is indicated as important. I read in some of his papers that protein elimination combined with caloric restriction has some benefits. I'm reading through a lot of this information. I always viewed a fast as total elimination of calories, so I never consumed anything other than water, broth, tea, coffee with no additives of fat sources or non-glucose contributing sweeteners. My thinking is that introducing any calories from fat or protein would defeat the purpose of the fast, which is to cause one's metabolism to obtain the required energy source from endogenous fat stores.

I'd also be interested to know if fat fasting could bring similar benefits. The longest fast I did was 7 days and I kept waiting for that day that the intense hunger would go away like other people had said, but for me that day never came.

I remember when there was all this fuss about calorie restriction... and it turns out carb restriction was just as useful. And a lot easier!

Dr. Mark Matson was featured in the TV documentary "Eat, Fast, and Live Longer" with Dr. Michael Mosley. You can watch this on youtube here. It also includes a segment with Valter Longo who researches calorie restriction and fasting and their effects on aging.

About IGF-1. GH stimulates the production of IGF-1 when GH hits the liver, where IGF-1 is produced. GH is inhibited by hyperglycemia. It follows therefore that when there's hyperglycemia, there's less GH, there's less IGF-1.

The effect seen where IGF-1 drops, it's the free IGF-1 that drops, not total IGF-1. Most of the IGF-1 is bound to some binding protein called IGFBP-x (where x is the number of this protein). This effect also comes with a concomitant increase in at least one of those binding proteins, as Rob cited in his original post here:

The correct phrasing here is: 50% decrease in free IGF-1, with a concomitant 5-fold or higher increase in one of the binding proteins (not "one of the principal IGF-1-inhibiting proteins"), IGFBP1. It is true that the binding protein renders the hormone inert or inactive (i.e. safe to keep it in the bloodstream, until received by any cell which can unbind it, so basically all cells), but it is not true that it inhibits it, in spite of what Wiki says about that. The term inhibition specifically applies to production and/or to its effect once received by cells through their receptors. For example, hyperglycemia inhibits GH production, or insulin inhibits ketogenesis, etc.

There's this idea that IGF-1 is somehow responsible for cancer growth. Not true. The primary culprits are glucose and insulin. Feinman did an experiment with cancer and KD. It has an effect on cancer growth. Maybe IGF-1 dropped, but I doubt it. Like I said, hyperglycemia inhibits GH, therefore inhibits IGF-1 downstream, therefore KD restores normal GH production, i.e. higher GH production than with hyperglycemia, therefore higher IGF-1 production. However, it's likely that KD is pretty much like fasting, so we'll get pretty much the same effect on the IGFBP-x as well. So the idea here is that in spite of an increase in IGF-1 production, we get a drop in free IGF-1 because there's more binding proteins to bind to that IGF-1.

Mind you, that's just how I understand it. I could be way off the mark on this one.

This bit is very telling:

Translation: Hyperglycemia, therefore a high-carb diet, adversely affects the brain.

That's all I need to conclude that it's not intermittent fasting or exercise that does what's done, instead it's the lack of carbs, the lack of excess insulin, and the presence of ketones that does what's done. That's all I need cuz it's very likely that all that work was done under the premise that a high-carb diet is good for us, that we need glucose for the brain, glucose is the preferred fuel, etc, etc, etc.

Is it just me or is this just wrong?:

If anything, stress was removed by intermittent fasting, since carbs were removed, hyperglycemia was removed, hyperinsulinemia was removed, ketones were added.

It's wondrous how even by starting with the wrong premise, the guy somehow stumbles into the right experiment.

Martin - I'm sure you're not wrong, but I'm reading it differently in regards to stress. If the base assumption here is that one's normal fuel is exogenous caloric consumption, then fasting introduces the stress required to convert a glucose-fueled metabolism to an endogenous fat fueled metabolism with the increase in ketone bodies. I can understand the use of "stress" in this case, but it's not the most clear way to describe what's happening. When stress caused by fasting results in increased ketones and reduced oxidative stress to the body and brain at the cellular level, the "stress" stimulates the metabolism to shift from glucose burning to fat burning. The word "stress" is used in two opposite ways here, and likely a better phrasing in explaining this is that the metabolism goes through an adaptive change due to fasting resulting in reduced oxidative stress and improved stress tolerance in the brain and body at a cellular level.

Thanks, Rob. I think you put it better than he did.

Re longer fasts, easier. I left out the huge "yeah, but." Tomorrow night I'll be with people, it's the weekend, etc.. Maybe if I start on on mondays and go thru Friday, the whole thing might work.

That's been my experience, as holidays, anniversaries, weekends are things I've got to navigate around. Starting with my last meal on a Sunday night seems to work for a few days, and I can bury myself in work during the course of the week.

Sort of related, here's a recent blog on the restriction of protein (specifically methionine) on aging.