Long-Term Fasting and Immune System

Introduction

The long term fasting on immune system recovery is a rather new research question in the area of nutrition and immunology. Long-term fasting is the ingestion of few or no calories over a long period of time, usually over 24 hours. Recent study shows that, prolonging fasting has tremendous physiological changes in the body and especially HSC (Hematopoietic Stem Cells), which are the ancestors of all kinds of blood cells including immune cells, are influenced by fasting. Moreover, scientists speculate that the changing at the cellular level will induce a regeneration of the immune system and increase health. For that reason, understanding the role of long-term fasting on the HSC activation and the immune system recovery has some significance on the medical researches.

Long-Term Fasting and Immune System Recovery

With prolonged fasting you avoid food for a longer duration and are still able to drink water. This causes your body to gradually switch from burning glucose for fuel, to using its stored fat to make up for the lack of energy. Because of this your body will go into a metabolic state known as ketosis which provides fuel when food is no longer available for extended amounts of time.

• The primary metabolic changes are:

• Lowered levels of insulin

• Increased fat breakdown

• Activation of cellular stress responses pathways

Activation of cell repair (autophagy)

These changes support an organisms ability to handle periods of energy deficit and may activate regenerative mechanisms of biology.

What Is Long-Term Fasting and Immune System Recovery?

Haematopoietic Stem Cells (HSCs) originate from the bone marrow. They are essential to the creation of red and white blood cells and platelets. HSCs are vital to a healthy immune system. With normal HSC functioning it produces the immune cells we need to fight of infections and illness.

Long Fasting and Stem Cell Activation

The study proposes a link between long-term fasting and rejuvenation of the immune system via the stimulation of hematopoietic stem cells. In a fasted state, a person’s levels of insulin-like growth factor 1 and protein kinase A activity decreased. It is thought that the body perceived this as a sign to preserve energy resources and induce the regeneration of its various systems.

Research has demonstrated that fasting can:

Stimulate HSC regeneration

Increase white blood cell production

Encourage an immune system rebuild following damage or prolonged damage.

It is through this regenerative ability that it seems a “reset” of components within the immune system. Are produced which in turn increases the effectiveness of the immune system.

Immune System Regeneration on Fasting

Long-term fasting may contribute to regeneration of the immune system by regenerating the immune cells. Under fasting conditions, the immune cells circulating in the body may be reduce as a way to spare energy. This may allow for reallocation of energy to other important physiological functions. Upon refeeding, there may be an increased stimulus in the body to produce new immune cells very rapidly. Thus, the regeneration of the immune cells may aid the health of the body.

The results might include:

 Better balance of the immune system

 Clearance of aged or damaged immune cells

 Increased ability to fight infection

 This is, however, still being research and is likely to vary among individuals.

Cellular mechanisms underlying fasting benefits

A number of mechanisms can be proposed that underlie fasting-induced advantages for immune regeneration:

Activation of autophagy, clearing cells and proteins that are no longer functional or useful

Decrease of chronic inflammatory stimuli on the immune system

Activation of stem cells for the replenishment of blood and immune cell populations

Shifting to metabolic efficiency and cellular maintenance and repair

Combined, the events occurring during fasting can improve over time the immune system’s ability to replenish and adapt.

Conclusion

The mechanism by which extended fasting can potentially aid in regenerating the immune system opens new paths of scientific exploration in biomedicine. Results show that through long fasting it is possible to stimulate hematopoietic stem cells, aid the rebuilding of immune cells and improve immune functioning. However, further clinical trials need to be conduct. Yet we can deduce that fasting could have a cellular healing mechanism and be beneficial for restoring the immune system when used appropriately.