“That which does not kill us makes us stronger” — Friedrich Nietzsche
If humans were unable to survive an occasional lean period when food was scarce — if indeed any animal couldn’t survive such lean periods — we’d have died out as a species long ago.
But all animals have a “fail-safe” built in. During that time, certain systems in our bodies go into survival mode.
In lower animals it occurs automatically. If you are a dog owner, you know that when your pet is not feeling well, it will not eat.
In humans, the instinct is not as strong. We must intentionally stop eating for this survival system to kick-in. We call it fasting.
Some dictionaries regard a fast as “the abstaining from certain foods for a period of time.” Others refer to it as “the total abstinence from all foods but not water,” a definition I will proceed under.
Next, we should distinguish between fasting and continued calorie restriction.
Fasting involves episodes of food restriction with the eventual resumption of normal food intake. Restriction is just eating less.
Studies written in The American Journal of Clinical Nutrition indicate that the ideal length of a fast for humans should be within the parameters of 36 to 60 hours. Calorie restriction, if continued beyond that which is necessary to maintain ideal weigh, can eventually be very debilitating.
So, what are the profound changes that happen from fasting?
From my previous columns you should understand how important our immune system is.
In a study done at the University of Pittsburgh School of Medicine with 15 human subjects, it was shown that immune parameters were improved, with some increasing as much as 24 percent.
In a 1945 study by Carlson and Hoelzel, they found that the apparent life span of rats in the study was increased by intermittent fasting, They showed that the optimum amount of fasting appeared to be one day in three, which increased the life span of males by about 20 percent and females by about 15 percent.
In the studies mentioned above, intermittent fasting was found to enhance cardiovascular and brain functions and improve several risk factors for coronary artery disease and stroke, including a reduction in blood pressure and increased insulin sensitivity.
In an excellent article out of the Scripps Research Institute in La Jolla, Calif., is a description of the process of autophagy, the term for the way the body cleans up cellular debris or “garbage,” including cells that can turn into cancer cells. The cells of our immune system destroy damaged body cells before they become cancerous, one way a healthy immune system protects us from diseases like cancer.
Although caloric restriction does offer some protection from cancer, repeated intermittent fasting can be much more effective.
The natural, fail-safe plan puts the individual — human or other animal — into a survival mode, strengthening that individual to survive many types of stressors that otherwise might kill him.
For example, if a lion grew weaker over long stretches between meals, he would soon be unable to effectively hunt. However, without food for a short period of time his senses become sharper and his running gets faster (although for shorter distances). If wounded, the immune system is brought to higher alert to prevent infection.
Unlike other animals, we as humans can intentionally call on this survival technique when we fast. The result: Our body is cleansed, our senses heightened, our defenses mobilized.
To sum it up, fasting can be a great help in increasing the potential of our immune and other survival systems. But to offer a word of caution, the duration of a fast must remain within the parameters of about 36 to 60 hours, though it can be repeated at weekly or monthly or other intervals one chooses.
Retired chiropractic doctor Francis Trapani’s background includes 41 years of practice plus doing investigative reporting and fitness programs for broadcast media in Hawaii. He has written three books and is working on a yoga self-help manual “The Doctor Prescribes Yoga.” For more information, click here.