By outlining how prolonged fasting cycles — periods of no food for two to four days at a time over the course of six months — kill older and damaged immune cells and generate new ones, the research also has implications for chemotherapy tolerance and for those with a wide range of immune system deficiencies, including autoimmunity disorders.
“We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system,” said corresponding author Valter Longo, Edna M. Jones Professor of Gerontology and the Biological Sciences at the USC Davis School of Gerontology and director of the USC Longevity Institute.
Fasting resets the hematopoietic immune system(15 posts) (5 voices)
Here's the free (for now) full text:
And the PDF download:
My fridge was empty anyway, so I stopped eating last night. It will be interesting to see how it goes; I'm shooting for three days. I don't get hungry anyway, being fairly well fat-adapted on a low-carb diet, but it's funny how once you know you can't eat, that's all you think about!
Of course for the reported benefits, you need to do this periodically, say once a month, for six months or a year.
Fasting report: I'm at the 65-hour mark, aiming for 72. Last night was not as challenging as I had feared, attending an event preceded by a barbecue; thankfully, I managed to ingest only water.
One thing that helped a lot was this second article/research paper by the same gerontologist, Valter Longo (how appropriate a name!) about a fast-mimicing diet to aid chemo patients, which has actually been tested on human subjects. This diet allows a restricted-calorie daily input. I figured if I have even less, with no carbs at all, it might not interfere with the fast. It helped stave off a slight headache and increasingly distracting thoughts about food :)
Washington Post article Here’s how a five-day diet that mimics fasting may ‘reboot’ the body and reduce cancer risk
In the study, which was published in the journal Cell Metabolism and funded by the National Institute on Aging, participants who intermittently fasted for three months had reduced risk factors for an amazing range of issues: aging, cancer, diabetes, cardiovascular disease. While the number of study participants was small -- only 19 who tried the diet -- the results are so promising that the University of Southern California researcher who helped develop the regimen is already talking about trying to get approval from the Food and Drug Administration so that it can be recommended for patients.
I'm trying to get the full text of the study. Here's the abstract.
Prolonged fasting (PF) promotes stress resistance, but its effects on longevity are poorly understood. We show that alternating PF and nutrient-rich medium extended yeast lifespan independently of established pro-longevity genes. In mice, 4 days of a diet that mimics fasting (FMD), developed to minimize the burden of PF, decreased the size of multiple organs/systems, an effect followed upon re-feeding by an elevated number of progenitor and stem cells and regeneration. Bi-monthly FMD cycles started at middle age extended longevity, lowered visceral fat, reduced cancer incidence and skin lesions, rejuvenated the immune system, and retarded bone mineral density loss. In old mice, FMD cycles promoted hippocampal neurogenesis, lowered IGF-1 levels and PKA activity, elevated NeuroD1, and improved cognitive performance. In a pilot clinical trial, three FMD cycles decreased risk factors/biomarkers for aging, diabetes, cardiovascular disease, and cancer without major adverse effects, providing support for the use of FMDs to promote healthspan. [emphasis added]
Re the study
(By the way, the final PDF version is now available. Full versions aren't always available indefinitely, so get it now if you'll ever want to read it.)
There are a couple of comments in scientific journals about this study, one enthusiastic, one a little more reserved.
The first is in Cell at Saying No to Drugs: Fasting Protects Hematopoietic Stem Cells from Chemotherapy and Aging
The benefits of DR and/or fasting in a wide range of preclinical models have been known for a long time (Robertson and Mitchell, 2013), yet corresponding dietary interventions are rarely tested in clinical trials. Instead, as underlying molecular pathways are revealed, attempts are generally focused on mimicking the effects of diet with pharmacological agents. To date, this approach has not produced effective fasting/DR mimetic drugs for aging or stress-related indications. This failure may be due to difficulties in delivering appropriate doses at the right time and place. However, it may also be that no single drug can effectively mimic the coordinated effects on gene expression, hormones and metabolism that can be achieved by simple yet pleiotropic dietary interventions such as fasting. Time will tell whether this potentially transformative work by Cheng and colleagues is better remembered for elucidating a druggable target pathway in HSC renewal or for demonstrating a viable dietary means to achieve the same end. [emphasis added]
At least the commenter acknowledges the possibility that diet as treatment is a legitimate contender. Western medicine usually wants to reduce things to marketable solutions (there is no research funding for non-lucrative treatments.)
Another comment, this time in Frontiers in Chemistry, Can UPR integrate fasting and stem cell regeneration? has a different interpretation of the chemical mechanism and is less enthusiastic:
Our understanding of the role of fasting under metabolic diseases stands well elucidated, and, in cancer, where the mechanisms are more complex, the role of fasting in regulating SCs regeneration and self-renewal may seem quite intriguing, but it is nascent in the present state. So, it remains an open question as how to connect the means to an end. What are the signaling pathways up-regulated while fasting in SCs? What are the key players that can serve as a bridge between fasting and SC regeneration? Conceivably, UPR and its signaling branch, the IRE1-Xbp1 and its downstream signaling molecules play a significant role in SC regeneration. An upbeat approach would be to understand the modulation of these downstream targets such as NRF2, FOXO transcription factors, and the state of ROS generation while fasting in SCs (Figure 1). Rest assured, therapeutic measures designed around them instead would serve as better alternatives. [emphasis added]
I'm not sure, as a lot of it is over my head, but it sounds like these guys prefer pharmaceutical interventions, something about which I feel about 180° different. See my remark above re lucrative treatments.
Thanks for posting this. Interesting stuff. I assume by your comments that you may try this. I'll be interested in hearing how you are doing after the 3rd month.
For those who may be interested,
here is a link that outlines the 5 day diet. The actual food suggestions allowed are located towards the end of the article.
As well, here are some more quotes from the study if anyone is interested.
If anyone elects to try this, please keep us posted on your progress.
I made it to the 74 hour mark, which included a 5 mile walk right before breaking the fast. I will make a separate post about the experience. I've got it on my calendar to do again in about a month, when I will shoot for four days.
Thank you for posting those links! The CR Society sounds very interesting and I look forward to investigating that site more closely.
As for the article in the New Zealand Herald, Are you ready for the 'fake fast' diet?, I have some definite thoughts about that, some of which are coming from my own particular context of already being on a very-low-carb diet. I'll write that up at my next opportunity.
Here's the full text of the study by the same researchers, about the fasting mimicking diet I mentioned above. Grab it now before it disappears behind a paywall, even if you don't think you're going to tackle it now.
I did a three day fast at the beginning of last month, and have resolved to do three or four days the first week of every month. You need to do this for six months or a year, according to the research. Please note, it's still experimental and has not been tested on humans, except in terms of making chemotherapy less awful, for which it seems to help a lot.
Here's my thinking: fasting should not be dangerous if you are in reasonably good health (and I feel disgustingly healthy, with just a few niggling mechanical problems). In lab animals, at least, this fasting protocol holds great promise for immunological problems, with evidence that suggests it resets the hematopoietic stem cell system. We have had four members of this forum undergo very expensive, rather risky hematopoietic stem cell transplants in Chicago, with mixed results. I'm volunteering to be a lab rat for the fasting protocol. I have to say, the first round of fasting felt rather great. Lost about 5 pounds, too.
Round 2 is coming up next week. I just have to make sure to schedule it around any upcoming barbecues, unlike last month.
Interesting overlapping concepts re calorie restriction (fasting). I know this series of articles focuses on cancer, but it could also have beneficial effects on other health problems, especially neurological. If you're not going to read all four articles, read at least #3 and #4. The following link leads to #3.
Twitchy, hi, and how is this going for you? I've been inactive on this forum for a while and just saw this. I've continued to bring progress of my MMN way down with basically the same paleo autoimmune protocol type diet I described on the FB forum some months back, along with stress reduction/lifestyle changes. No ivig. And it's all helping. My symptoms are much, much better than where I was a year or two back, but it's not the same as "it's stopped"--there's more to be done. So I was really intrigued by the USC study when I first saw it and am nearly ready to try it. So I'm curious! How did round 2 go? Are you eating reduced calorie or nothing but water for 2-3 days? Do you feel if it has any impact yet?
Christina, I'm sorry it took me this long to un-spam your post. I moved recently and was without internet for over a month.
I did the fasting thing for three months so far, but because of my recent changes it's been inconvenient. It didn't seem wise to fast for days on end while doing heavy physical labor like digging ditches in rocky soil! I do miss it, though. It was surprisingly habit-forming. I will pick it up again when I can.
I was doing almost completely water only, with just a little fat, like some butter, in some broth, or tea with heavy cream, on the second day. I think avoiding protein is key.
Twitchy, I was curious if you resumed fasting and if so, are seeing any impact? I was losing too much weight so I still haven't tried it, but now my weight has stabilized (b/c I added some things back in, like clarified butter and eggs) so I'm thinking again of giving fasting a try. Thanks!Posted 11 months ago #
Christina, sorry I didn't answer sooner. No, I haven't resumed fasting because I'm doing a lot of physical labor (building a house) and that doesn't seem like it would be a good idea! But I definitely plan to pick it up again once my life stabilizes.Posted 8 months ago #
Has anyone else tried this fasting? If so what were the results? Sounds interesting but I don't have a lot of weight to spare, I'm only 50 kgs and 170cm tall :-/Posted 7 months ago #
Here's a more recent article. The full text is free for the moment, grab it while you can.Posted 1 month ago #
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