Principios Teóricos

For patients undergoing prolonged fasts, blood tests and urinalyses are performed at approximately weekly intervals. This is necessary to help the physician decide how long to continue the fast. Some changes in laboratory parameters are normal, such as an elevation of uric acid. Other abnormalities, however, could indicate the fast should be concluded: Sometimes, moderate abnormalities in the blood tests or the patient's clinical status necessitate more frequent monitoring of these laboratory parameters.

Fasting almost always elevates the patient's uric acid level, frequently to very high values, but this does not cause gout and should be of no concern. The elevated uric acid levels are due to the increased breakdown of purines as well as the decrease in their elimination in the kidneys.

Some investigators have warned against fasting patients with a history of gout due to their concern that fasting may precipitate an attack. I believe that these fears are usually unfounded. What I and other physicians regularly employing fasts have observed is that even patients with a prior history of gout do not usually have attacks of gout on their fast. It is true that uric acid levels in the blood always rise to high levels in the fasting patient. Even with ,extremely high levels of uric acid, however, I have never seen an attack of gout on a fast. Other investigators report similar findings.8,9 _{Dr. Shelton, who}

reported conducting more than thirty thousand fasts, asserted that never once did he see gout develop in a fasting individual, in spite of high levels of uric acid.

This illustrates that an elevated uric acid level is not the only cause of gout. There are reports in the medical literature of patients with acute attacks of gouty arthritis who have normal serum uric acid levels;10 _{this illustrates that}

hyperuricemia and gout are often separate phenomena. Some other mechanism may be involved in gout besides the uric acid elevation, or the biochemical changes that occur in the fasting state may mitigate against the formation of uric acid crystals in the joints. Amazingly, even with supersaturation (uric acid levels rising to 18), episodes of gout are generally not experienced. There is a report of fasting precipitating an attack of gout in a patient Nvho had frequent prior attacks.11 _{My opinion is that even patients with}

a history of gout can fast safely if they follow a low-purine, vegetarian diet for three to six months prior to the fast and lose weight before the fast. This will resolve the gout condition before the fast begins.

hemoconcentration that occurs with a fasting-induced diuresis. If the hemoglobin value is too high, especially when accompanied by a relatively high BUN (blood urea nitrogen) level and high urinary specific gravity, the patient usually is not drinking enough water and must increase his or her water consumption.

Due to the body's built-in survival mechanisms, the amount of water needed while fasting is minimal. The desire for fluid diminishes and may be nil in some fasters. To minimize side effects and assure the safety of all patients, however, fasters need to be encouraged to drink water to prevent dehydration. One quart of water per day is usually sufficient for most individuals, but some need to be encouraged to drink two or more quarts, depending on their laboratory parameters.

Dehydration does not generally occur in the overweight patient. Rather, it is seen more frequently in the thin patient. If considerable dehydration ensues, the patient should be fed. Because dehydration due to fasting is secondary to electrolyte depletion, it is possible that increasing the amount of water given the faster will not be sufficient to correct the abnormality. Therefore, if serious dehydration results, the fast should be broken with an appropriate food such as fresh orange juice, vegetable juice, or watermelon.

One of my patients with asthma, who had tried to fast with another physician in the past, claimed she vomited and became nauseated whenever she fasted. Therefore, she could not fast for longer than a few days. After fasting her a few days, as predicted, she developed vomiting and nausea. I then looked at her blood and urine and it showed she was dehydrated with hemoconcentration (increased red blood cell concentration) and an increased BUN level. When I asked her if she was drinking at least four glasses of water a day as I had recommended, she said she never likes to drink much when she fasts. She was drinking less than 8 ounces of water a day. As soon as I corrected this by increasing her fluid intake, the problem stopped and she was able to fast without difficulty.

It is to be expected that the glucose level will fall and remain at low levels during the fast, typically between 40 and 65, except in the type II diabetic patient, who may have a near normal or slightly elevated glucose level during the fast. If it is imperative for a person with type I diabetes to fast, glucose levels should be tested regularly and the insulin dose appropriately adjusted to the lowered needs of the fast.

Electrolytes such as potassium, sodium, and chloride are exceedingly stable during a fast. Even though early in the fast the body loses quite a bit of sodium and potassium, this excretion falls as the fast progresses. Generally, the electrolytes remain at low normal levels throughout the rest of the fast. If the potassium level drops to 3.2, the fast should be broken unless the physician supervising the fast chooses to monitor the blood test more frequently to make sure the level does not continue to drop. Obviously, once the level has reached 3.2, one should not wait a week to run the next potassium check if the patient continues the fast. I recommend ending a fast for any person who has a

potassium level lower than 3.0.

At any sign of sudden, extreme weakness during a fast, the potassium level should be considered suspect and rechecked. However, gradual loss of energy or the slow development of weakness as the body attempts to conserve energy by decreased activity is normal during the fast and to be expected.

Liver enzymes occasionally increase early in the fast. As the fast continues, they slowly return to normal. I have noted the elevation of liver enzymes more frequently in patients with autoimmune illnesses, connective tissue disorders, and psoriasis; this may represent the contribution that inadequate liver function contributed to their underlying disease state. In the psoriasis patient, for example, and even in fibromyalgia patients, the return to normal liver function during the fast or soon after parallels the improvement in their skin disease or symptoms of muscle pain.

Due to the large demands on the liver for energy metabolism early in the fast, bilirubin levels rise initially and then fall gradually as the liver adapts to the fasting state.12

Cholesterol levels increase considerably in the fast, reflecting a breakdown of atheromatous material. As discussed in Chapter 5, the level of total cholesterol may double over the patient's baseline in an individual with a history of atherosclerotic plaque, whereas the patient without diseased arteries will not show such an increase in cholesterol. Both LDL and HDL levels increase, but I have noted that the sharp rise in cholesterol in cardiac patients is predominantly of the LDL type.

Other researchers have noted minimal increases in cholesterol levels and a more predominant increase in the HDL component. These conflicting findings may represent the increased level of activity encouraged or permitted by other researchers and the fact that juices may have been consumed.13 _{I interpret the}

strikingly higher elevation of LDL cholesterol seen in my fasting patients with atherosclerosis as being due to the increased effectiveness of the total fast over "juice fasting" in breaking down atheromas. I also forbid vigorous exercise, permitting only gentle back-mobility movements, flexibility and joint-mobility exercises, and a little walking.

Many physicians who routinely monitor blood cholesterol levels in their office are not aware that an elevation of cholesterol occurs even when a patient fasts overnight for a blood test and then has it drawn late in the day rather than in the morning. Fasting lipid profiles should be drawn first thing in the morning to prevent this phenomenon from disturbing the results.

Physicians may also be confused and the patient disappointed and discouraged when the individual who started adhering to a strict, extremely low-fat, zero-cholesterol diet has an increase rather than a decrease in his or her cholesterol level. I have noted from monitoring the lipid profiles of many such patients that not only is it possible to observe a temporary rise in triglycerides during this adjustment phase, but also the total cholesterol may

occasionally rise significantly. When this occurs, it is observed during the first two to six months after the dietary change; then these lipid levels begin to drop and show notable improvement later on. My patients are often warned not to be discouraged by the early tests, which do not yet represent their significant decreased risk.