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Does IF damage the heart?

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I'm trying to find Michael Rae's very old post about this topic and I could be mistaken that he mentioned in the distant past that IF may damage the heart. Unfortunately, I am having difficulty finding the original post from the old imminst forums before it became longecity.

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I don't know about that post, but I don't recall seeing a study which suggests so.

Perhaps there is confusion because during fasting, cholesterol levels in the blood shoot up?

"... The participants' low-density lipoprotein cholesterol (LDL-C, the "bad" cholesterol) and high-density lipoprotein cholesterol (HDL-C, the "good" cholesterol) both increased (by 14 percent and 6 percent, respectively) raising their total cholesterol -- and catching the researchers by surprise.

"Fasting causes hunger or stress. In response, the body releases more cholesterol, allowing it to utilize fat as a source of fuel, instead of glucose. This decreases the number of fat cells in the body," says Dr. Horne. "This is important because the fewer fat cells a body has, the less likely it will experience insulin resistance, or diabetes.""

https://www.sciencedaily.com/releases/2011/04/110403090259.htm

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I read through that longecity thread, and it's fair to say "it's complicated" (isn't everything in medical science?). First and foremost, this is EOD - so if you are practicing every other day fasting, then it might be relevant - I think few of us are. People sometimes practice limited window feeding (4, 6, 8 hours), resulting in 16+/- hours of fasting within a 24 hour window - and call it "intermittent fasting" - that is NOT the same thing.

The second problem is that this is a study in rats. Sorry, I know a lot of CR results do appear to translate roughly from rats to humans, but these are still rats, and therefore you simply cannot say "because result X translates to humans therefore we assume that result Y will too". I find the objection "it's rats!" particularly relevant in this case - because it hits at one of the weak points of translatability to humans - time scale and circadian rhythms. EOD in a rat is not the same as EOD in a human - a 24 hour fast in rats is much more stressful for a rat physiology than it is for a human.You would not take the same absolute amount of a drug and administer it to both a rat and a human and declare the results equivalent, so why would you administer the same amount of time (24 hours) in an intervention and expect it to be equivalent in effect in rat and human. In conclusion, I say yet again - to hell with results in rats/animals; give me results in humans or I put it on "ignore". 

Does IF damage the heart? - this is an example of Betteridge's Law of Headlines which says, "Any headline that ends in a question mark can be answered by the word no."

In this case the evidence cited for possible concern is derived from RAT studies. That right there - yeah, no thanks. 

My principle - which I've been promoting endlessly on these boards - is: Result in RATS/animals ---->IGNORE.

Personally, I find this result to be irrelevant to my life. YMMV, obviously. 

 

 

Edited by TomBAvoider

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2 hours ago, TomBAvoider said:

...

Personally, I find this result to be irrelevant to my life. YMMV, obviously. 

 

 

Yep. Some older rat studies, generally contradicted by other rat studies and more recent human studies (I cited one above, but there are more, and more recent ones that I've come across).

I just haven't seen anything notable to lend significant support to the "Mess Up Your Heart..." headline. I am not a big faster, but I have seen enough studies to lend pretty strong support to the practice.

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Quote

TomBAvoider:   People sometimes practice limited window feeding (4, 6, 8 hours), resulting in 16+/- hours of fasting within a 24 hour window - and call it "intermittent fasting" - that is NOT the same thing.

 

Valter Longo recommends a 11-14hr eating window, citing possible side effects, including cardiovascular disease, for longer periods.   I don't have time at the moment to track down the scientific basis for those concerns.
 

Quote

Another common practice adopted by many centenarian groups is time-restricted eating, or confining all meals and snacks to within eleven to twelve hours or less a day. The efficiency of this method has been demonstrated in both animal and human studies. 6 Typically you would eat breakfast after 8 a.m. and finish dinner before 8 p.m. A shorter eating window (of ten hours or less) can be even more effective for weight loss, but it is much harder to maintain and may increase the risk of side effects, such as developing gallstones and possibly increasing the risk of cardiovascular disease. You should also not eat within three to four hours of going to sleep.

  The Longevity Diet (p. 64).  Kindle Edition.

Edited by Sibiriak

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On 6/11/2019 at 6:59 AM, Sibiriak said:

...possibly increasing the risk of cardiovascular disease

Now, after the recent thread on postprandial tachycardia, a mechanistic principle for CVD hazard may be invoked simply by the fact that larger meals (inevitable situation when intake is not spread out throughout the day) may cause significant increase in heart BPMs. This may become more pronounced with a single meal per day. As I commented in the other thread, I could not eat a single meal because of the bloating and the consequent heart rate increase. Is such a BPMs increase comparable to physical activity? I believe not, that's pretty unpleasant in my experience.

Re. Gallstones, just today I've been talking meals with a medical colleague at work, the mechanistic cause of gallstones might be the concentration of the gall fluid when it is not secreted  with a certain frequency and the easier precipitation of salts and minerals in it.

Edited by mccoy

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