Please note, I am not really considering doing it- I am only interested in the objective science of what an extended water-only fast would mean for long-term health and longevity.
I've read here and there about how when you are fasted for this long, the body will essentially dissolve any and all diseased/useless/harmful tissue, build-ups etc. Would things such as tumors, arterial plaques etc be ridden by a long-term fast?
Does anyone have any personal experience, or scientific/medical information to support/refute any of these notions?
And also, I am aware of several studies/references that discuss the effects on an individual's offspring after prolonged periods of food deprivation... but I am not interested in that with this question either.
asked byDaniel_2 (545)
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on February 09, 2011
at 04:49 PM
Does anyone have any personal experience...
Yes, I've fasted (water only) for 30 days. My fast is described in this entry on the Perfect Health Diet blog.
...or scientific/medical information to support/refute any of these notions?
There are many peer-reviewed papers on fasting going back to the nineteenth century... hundreds of them. Nobody can summarize this literature here; there's too much information. Here's a good general review article on fasting from the medical literature:
Here's a fascinating article about the longest fast in the medical literature. This guy fasted for 382 days.
You ask about absorption of unwanted tissue. This is called autophagy. Fasting induces high levels of ketosis, and ketosis promotes autophagy, so yes, most likely fasting does promote resorption of some unhealthy material in the body. Whether that material includes atheromas, I don't know. I don't recall seeing any papers on that subject but there may be some.
Edit: It just occurred to me that if any such paper exists, it would be cited in Joel Fuhrman's book Fasting and Eating for Health (see citation below). Sure enough, on page 113 he claims that there is one paper that showed regression of atheromas in fasted nonhuman primates.
However I just read the paper and it shows no such thing. The nonhuman primates weren't fasted; they were put on either a low-fat diet or a diet supplemented with a particular kind of fat. Fuhrman misrepresents the study. Here's the paper if anybody wants to check:
There is evidence that fasting (or deep ketosis induced by extreme ketogenic diets) can kill some types of cancer cells. (Fasting and extreme ketogenic diets are related because ketogenic diets simulate fasting.) Just a couple of months ago, the first paper was published describing a successful use of this therapy in a human patient. This patient's brain tumor shrank. However it probably didn't shrink because of autophagy. It probably shrank because the cancer cells starved to death, due to the fact that cancer cells cannot use ketones for nourishment. The paper is here:
One of the scientists who is involved in this anti-cancer work is named Thomas Seyfried. He advocates fasting for seven to ten days once a year as a preventative measure for cancer. If you google his name, you'll find a couple of interesting interviews with him. For example:
I'm describing peer-reviewed science here. There are also popular books written by doctors who have lots of clinical experience supervising therapeutic fasts. They make many interesting claims about cures of various diseases. Whether these claims are true, I don't know. The best recent book of this type is this one:
Furhman, Joel. Fasting and Eating for Health (1995). St. Martin's Griffin: New York.
Finally, let me give you a link to a fascinating interview with a woman whose unremitting 16 year headache (due to inflammation of the dura mater) was cured by fasting. She's a patient, not a doctor or scientist, but she's extremely intelligent and articulate.
on May 07, 2013
at 08:17 AM
I did a 24 day water fast about two years ago and now do a yearly 5-7 day water only fast.
I was 36% body fat at the time, which made it very easy as hunger goes away after two days if you have adequate fat stores and skeletal muscle. I estimated that I loss 1/6 of a lb of lean muscle mass and 1/2lb of fat per day after the initial water glycogen in week 1. The muscle mass loss becomes less after day 3 if your body (brain) can use less glucose which can only come from amino acids.
As for the effects: mood altering, euphoria, naturally sleeping 6-7 hrs from 8-9 (no digestion to require extra energy)
Just note that your liver can only produce so many ketones per hour, but I was able to work my day job the entire 24 days, and I did 1-2 miles of walking per day and some squats and push-ups to signal muscle sparing.
The autophagy and antiviral and oncology research I think will show many benefits if you do some Proquest DB journal searches.
on November 18, 2012
at 12:37 AM
Herbert Shelton. Read his books. He is the guru for fasting.
on February 09, 2011
at 05:29 PM
This might be a dumb remark, but since cancer cells feed on sugar would a zero-carb paleo diet have +- the same effect as a fast?
on February 09, 2011
at 04:45 PM
What would you call 'extended'?
I cannot offer references to any medical information or anything, but I can offer (somewhat limited?) personal experience.
My longest water-only fast so far has been four days, around 96 hours - certainly not as long as you are asking about but I feel the results are worth sharing.
Obviously first and foremost I lost a lot of 'weight', although I am sure the majority was water. I noticed a couple of things though; my skin felt and looked so much healthier afterwards. Particularly the dry skin on my hands which I get every winter. My stomach, which can be quite troublesome even eating within a Paleo framework (I am sure I can hack this somehow), improved dramatically and this effect remained after the fast. My energy increased as the fast went on and I experienced great mental clarity. I continued to work out during these four days and although initially I felt slightly weaker than usual, I did not suffer any loss in strength.
I do feel that extended fasts can offer a lot and it would make sense to me that the cellular necrophagy that would occur could be of great significance. As for dissolving tumors and ailments of that nature...I am not so sure. I do think it would have a positive impact though.
I am interested to hear other people's opinions on this as fasting is something I very much believe in. Thanks for asking the question.