In regards to fasting:
I liken the body to a sponge.
When a sponge is constantly saturated, it cannot absorb additional volume.
If you have a dirty sponge, you cannot clean it out by simply submersing it in clean water.
It is only when you totally wring out the sponge, and expunge it’s total liquid volume, that you are able to introduce clean water, and refresh the sponge.
Likewise, when the body is constantly saturated with glucose, which stimulates insulin and signals to cells to absorb additional volume (ie nutrients that piggy back off the glucose), you cannot expunge cell waste, and introduce needed nutrients.
It’s only when you allow the body to expunge/ deplete it’s glycogen stores, via fasting, or intense/ prolonged exercise coupled with a restricted diet, that nutrients can be introduced to refresh and revitalize cell function.
If you don’t allow your body to enter a calorie restricted state, so that glycogen stores sufficiently deplete, and cell waste adequately purge, then no amount of nutritious eating will heal and benefit the body: you cannot introduce nutrients when the body is saturated with glucose. The cells won’t allow anything else to enter: they’re full.
The following study complements this analogy by demonstrating that excess internal cell glucose prevents the uptake of Vitamin C, a vital nutrient to cell function:
Preloading the vesicles with glucose inhibited ascorbate uptake similarly, indicating that glucose interferes with the ascorbate transporter from the internal side of the membrane. The results of this study suggest that DHAA crosses the apical membrane by facilitated diffusion, whereas ascorbate transport is a Na(+)-dependent, electrogenic process modulated by glucose.
There is a theory that complements this line of thought, called the Glucose-Ascorbate-Antagonism (GAA).
Essentially, glucose and vitamin C are so chemically similar, that they compete for the GLUT-1 receptor.
White blood cells may contain 20 times Vitamin C than other cells, and up to 50 times more than blood plasma, in order to combat oxidation.
In white blood cells, glucose has a much greater affinity for this receptor. In addition, white blood cells have more insulin pumps than any other cell.
When white blood cells encounter pathogenic bacteria and viruses, they must ingest or phagocytize these organisms in order to neutralize them. The phagocytic index measures how effective a particular white blood cell is at destroying viruses, bacteria & cancer cells. Elevated blood sugar impairs this phagocytic index. In fact, a blood sugar of 120 reduces the phagocytic index by 75%.
Glucose and ascorbic acid also work on the hexose monophosphate (HMP) shunt. The HMP is a biochemical pathway that produces NADPH. White blood cells need NADPH to create superoxide and other reactive oxygen species that oxidize and destroy pathogens. Vitamin C not only helps produce NADPH, but also regulates quantities so the white blood cell does not create too much oxidative stress in its attempt to protect the body.
Vitamin C activates this important shunt while glucose inhibits it. This HMP shunt also produces ribose and deoxyribose, which provide important raw materials for the formation of new white blood cell RNA/DNA. When the immune system is under attack, it needs to quickly produce new immune cells. If blood sugar is high enough to turn off the HMP shunt, it will reduce the quantity of RNA/DNA and the amount of new immune cells formed.
Excess glucose results in increased oxidative stress on the body, which leads to increased inflammation and leaves the body vulnerable to disease.