Fasting For Health: Could This Practice Actually Be Dangerous?

Fasting involves restricting your dietary intake to a liquid. The liquid may be water, tea, or fruit juice. Proponents of fasting recommend occasional regular short fasts, lasting two to five days, as part of a general health-maintenance regimen. Advocates recommend that longer fasts for health maintenance or the healing of illness, lasting a month or more, be conducted under medical supervision.

For fasts lasting more than one week, fruit juices are given to supply the nutrients needed to maintain health. Some add enemas as part of the detoxification fasting regimen. Proponents claim that because the body is relieved of its usual chore of breaking food down into its elemental nutrients, fasting allows the body's inner resources to focus on cleansing and healing. Cleansing is said to be accomplished through the elimination of existing toxins.

Fasting claims to enhance the immune system and reduces the demands placed on it. In addition to its role as part of health maintenance, some believe that fasting is an effective way to treat illnesses, including arthritis, ulcers, heart disease, asthma, and other problems.

The ancient belief that fasting purifies the soul has been extended to the current view that fasting also can purify the body. Fasting maintains and restores health through physiological mechanisms. Included in these mechanisms are shifting physiological effort from food conversion to the elimination of toxins, reducing the immune system's workload, releasing pesticides and other chemicals from body fat, and eliminating the body of nonessential tissue.

It is helpful to look at these beliefs in terms of scientific information about the well-studied sequence of events that occurs when people start fasting. When body weight declines, water and fat, but not toxins, are lost from cells. Toxins are left behind. Nutrients are needed to sustain immune competence, the ability of the body's disease-fighting immune system to make antibodies and other proteins and cells. Immune system failure, not enhancement, occurs when people do not eat enough to provide the nutrients that sustain proper immune function. Instead of reducing its workload, fasting impedes the immune system.

Advocates explain that people feel sick when fasting because toxins are leaving the body. Actually, fasting decreases the immune system's ability to destroy and eliminate toxins. Fasting also causes a drop in blood sugar levels, which causes a breakdown of tissues needed for energy. This leads people to feel sick because the brain and other tissues fail to receive needed sugars, and the body's metabolism is forced to remove the needed nutrients from muscle and liver tissue. At the same time, the liver and kidneys are not able to do their work of handling the by-products of protein breakdown.

Fasting can harm all organs. It is extremely dangerous to health, especially for those who are malnourished by chronic illness, yet some proponents recommend fasting to treat chronic illnesses. The slimmer the individual, the more dangerous a fast will be. The longer the fast, the more life-threatening it becomes. Studies show that when people reach 56% of their appropriate body weight, death occurs. The body cannot distinguish between intentional fasting and starvation.

Solid scientific research does not support the claims of fasting advocates. To the contrary, it contradicts those claims and indicates the dangers of fasting, even with water or juices. Reducing the number of calories you eat while maintaining a normal, balanced diet will reduce your weight. But consuming only water, tea, or juice is harmful, not helpful, to health and should be avoided especially by those who are ill.

Advocates believe that fasting can produce fatigue, anemia, irregular heartbeat, body aches, nausea, dizziness, and other negative effects. They refer to these as temporary problems that precede feelings of well-being, mental clarity, internal cleanliness, and other benefits.

Contrary to advocacy claims, fasting does not and cannot heal medical conditions, assist immune or other physiological function, or play a role in health maintenance. The decreased supply of blood glucose leads the body to break down muscle for energy, causing weakness, depression, fatigue, and sick feelings.