FASTING PROTECTS AND REJUVENATES A DAMAGED OR AGEING IMMUNE SYSTEM
I’ve written about the benefits of fasting before and do recommend fasting on occasion to improve your health. As part of my healthy lifestyle, I fast at least one day per week, usually on the weekend. It’s sort of become routine now, so I don’t really find it that difficult. On my fasting day I will just drink a lot of green tea! Like 10 – 15 cups. 🙂 Some people might have problems with drinking green tea on an empty stomach though, because the tea contains tannins, which can cause a little bit of nausea.
So, a new study was just released in the journal Cell showing that fasting has remarkable effects on the immune system. It seems that just fasting for one day is not enough to induce a strong response either – one would need to fast between 2 – 5 days!
The study found the following changes occurred after repeated fasting cycles
- Fasting downregulated the IGF-1 / PKA pathway in stem cells
- Fasting protected cells from the effects of chemotherapy
- Fasting promoted stem cell renewal and reversed chemotherapy induced immunosuppress
Initially the fasting caused a drop in white blood count, but then after re-feeding, the white blood count was increased to normal levels. This has effect has also been observed in animals and people on calorie restriction and is one of the reasons why it’s important that you get a full blood count test before starting the diet so that you can get a baseline number. I noticed my own WBC drop after starting calorie restriction – especially lymphocyte count.
In the past researchers have shown that when mice are fasted before given chemotherapy or radiation treatment, they are able to survive much higher doses without any negative effects. This study confirmed what has been found before – fasting protects the mice from chemotherapy drugs. In fact, 100% of the mice that were fasted survived compared to just 40% of the animals that weren’t fasted [Figure 1B]. They also noticed that the lymphocyte count was normalized in the fasted mice. In animals, and probably humans, repeated cycles of fasting can rejuvenate an immune system that has been damaged from toxic drugs or ageing.
What the researchers investigated
They were looking at quite a few things: The effect of prolonged fasting on mice exposed to chemo therapy and looking at the level of apoptosis to a subpopopulation of cells ( LT-HSCs, ST-HSCs, and MPPs) after 6 cycles of prolonged fasting (PF) + Chemo (CP) or chemo alone. Compared to just chemo, they saw that prolonged fasting was able to have a significant effect on preventing cell death. The researchers looked at the length of time it took to recovery of lymphocyte count in control mice and found it took 70 days (6 cycles ) before recovery was seen; but in the fasted mice, the count was decreased independently by the fast and recovery of lymphocyte count was seen earlier at day 40 (cycle 4) probably because of the increased resistance to apoptosis of progenitor cells. By cycle 5 the fasted mice displayed a more normal lymphocyte / myeloid ratio as well, indicating higher resistance to the toxic effect of chemo.
In a separate experiment they were looking at the effect of fasting on old mice and populations of LT/ST – HTCs after 8 cycles of fasting. The researchers noted a temporary drop in white blood count during fasting, but an increase, over time, in HSCs above that of Young-AL & Old-AL mice. There was an increase to normal youthful levels because of the shift in balance by the end of cycle 8. A rejuvenation effect of the immune system. This is a very important and profound result!
Phase 1 trials on human have been completed. Cancer patients noticed less symptoms associated with chemotherapy when they were fasted for up to 72 hours before treatment. The effect on PF + CP on humans is quite dramatic as it almost ameliorated the significant drop in chemo induced lymphocyte count as you can see in the table S1 in the supplementary data in the paper . Researchers are currently planning phase 2 clinical trials to expand their research onto larger randomized groups of people.
This is an extremely exciting area of research and something we can learn from and apply today. I wouldn’t personally try to fast for 5 days as 3 days seems to be sufficient. I’m considering trying to do a 3 day fast, once per month, in addition to my 24 hour fast each week. I’ll let you know when I start! 🙂
Watch one of the researchers of this study talk about the benefits of fasting on cancer
 Prolonged Fasting Reduces IGF-1/PKA to Promote Hematopoietic-Stem-Cell-Based Regeneration and Reverse Immunosuppression