“Immune system defects are at the center of aging and a range of diseases. Here, we show that prolonged fasting … (leads) to … changes in long-term hematopoietic stem cells and niche cells that promote stress resistance, self-renewal, and long-age-balanced regeneration.” ~ Longo, V.D., et al.: Prolonged Fasting Reduces IGF-1/PK to Promote Hematopoietic-Stem-Cell-Based Regeneration and Reverse Immunosuppression
Whew … did you get all of that? If not, here’s a layman’s (my own) paraphrase: Fasting – abstaining from all or some kinds of food or drink – promotes the birthing of cells while fighting against many of the things that cause aging, stress, and fatigue.
Not bad, eh? But let’s take a step back and more specifically discuss the study’s finer points.
Here are the benefits of fasting for your body:
Fasting and the Immune System
In a nutshell, here’s what the scientists discovered:
“Prolonged fasting (PF) lasting 48-120 (hours) reduces pro-growth signaling and activates pathways that enhance cellular resistance to toxins in mice and humans.”
A couple of things:
– Using simple math, we convert 48 to 120 hours to 2 to 5 days. (That’s a long time to go without eating, huh? More on this later.)
– Per the authors, an extended period of fasting is required to achieve the specified health benefits. Relatedly, restricting calories does not appear to be useful:
“The physiological changes caused by PF are much more pronounced than those caused by calorie restriction or fasting lasting 24 hours or less.”
Key Findings of the Study
First and foremost, this research has some serious implications for both healthier aging and cancer treatment. Length of life depends heavily on how well our cells hold up, which in turn depends on the health – and sustained normal function – of our immune system. Consequently, immune system dysfunction is the catalyst for many potentially life-ending cancers and diseases.
Regarding immune system function, it tends to become less effective as we age. Some destabilization or inhibition of this system is to be expected as a consequence of life’s “wear and tear,” so to speak. Genetics, environment, and lifestyle all play a role here.
However, effective functioning of the immune system declines much faster when actively and continuously repelling harmful foreign agents (e.g., bacteria, toxins, etc.). Scientists call these toxic effects on the immune system response immunosuppression, as it inhibits normal operation of the immune system.
The research team studied the role of multiple cycles of prolonged fasting on both age-dependent and chemotherapy-induced immunosuppression. As the study notes, chemotherapy drugs are known to induce cell death and DNA damage in bone marrow – a side effect that effectually prevents, to a large extent, cellular genesis.
Promisingly, prolonged fasting was found to protect the system that helps produce new cells – not just for chemotherapy patients, but for otherwise-healthy individuals!
The Hematopoietic System
The hematopoietic system, consisting of the lymph nodes, bone marrow, spleen, and thymus, is responsible for producing the blood components of cells. In other words, it creates necessary components of the blood that permit life.
It is this system that “(provides) a rich source of stem cells used to treat a variety of cancers, anemias, AIDS, and sickle cell disease,” according to Columbia University.
This brings us to perhaps the most poignant statement on the possible consequences of this groundbreaking study. Valter Longo, professor of gerontology and biological sciences at the University of Southern California (USC) Davis School of Gerontology and the Director or the USC Longevity Institute, says:
“We could not predict that prolonged fasting would have such a remarkable effect in promoting stem cell-based regeneration of the hematopoietic system.”
“When you starve, the (body) tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged,” says Longo.
Extended periods of fasting (“prolonged fasting”) puts the body in a state conducive to cellular recycling. Besides obliging the body to burn fat, glucose, and ketones as energy, the process of fasting also breaks down old white blood cells (WBC’s).
Through the fasting cycles, the elimination of WBC’s is followed by a regeneration phase; specifically, the birthing of new immune system cells. Besides creating new immune system cells, prolonged fasting also reduced IGF-1, which Dr. Longo, his colleagues, and others link to aging, cancer risk, and tumor growth.
Accelerated recycling of immune system cells could make a big difference when it comes to preventing and treating diseases and other medical conditions. Extended periods of fasting, as it turns out, may be the answer.
Keep in mind that fasting is not deemed safe for everyone. It is particularly dangerous if your diet is unhealthy or if you have a liver or kidney condition. Those on prescription medications would be wise to consult with their physician before going on a fast.
Per WebMD, a 24 to 48-hour fast is otherwise “rarely a problem if you are healthy.”