The Health Benefits of Fasting
by Will Carroll

There has been much contention in the scientific field about whether
or not fasting is beneficial to one's health. Fasting is an integral
part of many of the major religions including Islam, Judaism and
Christianity. Many are dubious as to whether the physiological effects
are as beneficial as the spiritual promoted by these religions. There
is a significant community of alternative healers who believe that
fasting can do wonders for the human body.

Fasting technically commences within the first twelve to twenty-four
hours of the fast. A fast does not chemically begin until the
carbohydrate stores in the body begin to be used as an energy source.
The fast will continue as long as fat and carbohydrate stores are used
for energy, as opposed to protein stores. Once protein stores begin to
be depleted for energy (resulting in loss of muscle mass) a person is
technically starving.

Detoxification is the foremost argument presented by advocates of
fasting. "Detoxification is a normal body process of eliminating or
neutralizing toxins through the colon, liver, kidneys, lungs, lymph
glands, and skin."  This process is precipitated by fasting because
when food is no longer entering the body, the body turns to fat
reserves for energy. "Human fat is valued at 3,500 calories per
pound," a number that would lead one to believe that surviving on one
pound of fat every day would provide a body with enough energy to
function normally.  These fat reserves were created when excess
glucose and carbohydrates were not used for energy or growth, not
excreted, and therefore converted into fat. When the fat reserves are
used for energy during a fast, it releases the chemicals from the
fatty acids into the system which are then eliminated through the
aforementioned organs.

A second prescribed benefit of fasting is the healing process that
begins in the body during a fast.  During a fast energy is diverted
away from the digestive system due to its lack of use and towards the
metabolism and immune system.  The healing process during a fast is
precipitated by the body's search for energy sources. Abnormal growths
within the body, tumors and the like, do not have the full support of
the body's supplies and therefore are more susceptible to autolysis.
Furthermore, "production of protein for replacement of damaged cells
(protein synthesis) occurs more efficiently because fewer 'mistakes'
are made by the DNA/RNA genetic controls which govern this process." A
higher efficiency in protein synthesis results in healthier cells,
tissues and organs.  This is one reason that animals stop eating when
they are wounded, and why humans lose hunger during influenza. Hunger
has been proven absent in illnesses such as gastritis, tonsillitis and
colds. Therefore, when one is fasting, the person is consciously
diverting energy from the digestive system to the immune system.

In addition, there is a reduction in core body temperature. This is a
direct result of the slower metabolic rate and general bodily
functions. Following a drop in blood sugar level and using the
reserves of glucose found in liver glycogen, the basal metabolic rate
(BMR) is reduced in order to conserve as much energy within the body
as can be provided.  Growth hormones are also released during a fast,
due to the greater efficiency in hormone production.

Finally, the most scientifically proven advantage to fasting is the
feeling of rejuvenation and extended life expectancy. Part of this
phenomenon is caused by a number of the benefits mentioned above. A
slower metabolic rate, more efficient protein production, an improved
immune system, and the increased production of hormones contributes to
this long-term benefit of fasting. In addition to the Human Growth
Hormone that is released more frequently during a fast, an anti-aging
hormone is also produced more efficiently. "The only reliable way to
extend the lifespan of a mammal is under-nutrition without
malnutrition."  A study was performed on earthworms that demonstrated
the extension of life due to fasting. The experiment was performed in
the 1930s by isolating one worm and putting it on a cycle of fasting
and feeding. The isolated worm outlasted its relatives by 19
generations, while still maintaining its youthful physiological
traits. The worm was able to survive on its own tissue for months.
Once the size of the worm began to decrease, the scientists would
resume feeding it at which point it showed great vigor and energy.
"The life-span extension of these worms was the equivalent of keeping
a man alive for 600 to 700 years."

In conclusion, it seems that there are many reasons to consider
fasting as a benefit to one's health. The body rids itself of the
toxins that have built up in our fat stores throughout the years. The
body heals itself, repairs all the damaged organs during a fast. And
finally there is good evidence to show that regulated fasting
contributes to longer life. However, many doctors warn against fasting
for extended periods of time without supervision. There are still many
doctors today who deny all of these points and claim that fasting is
detrimental to one's health and have evidence to back their
statements. The idea of depriving a body of what society has come to
view as so essential to our survival in order to heal continues to be
a topic of controversy.

The complete version of this paper can be found at:
http://serendip.brynmawr.edu/biology/b103/f02/web1/wcarroll.html