Dear Dr. Blonz: I continue to read about fasting and cleansing and their ability to release toxins that have built up in the body. Is there a difference of opinion among professionals in nutrition about the release of toxins in this way? Do you see any potential here? — S.E., Arizona
Dear S.E.: The concept of the “release of toxins” during a fasting or cleansing routine is dubious. Many of the arguments are either theoretical (“I think it might work”) or anecdotal (“some tried it and thought it worked for them”). To this, we add the fact that there is little if any data or evidence in the journals to support the efficacy of these procedures. As they should, science-trained professionals tend to reject concepts where there is a lack of objective evidence.
Some connect how they feel during fasting/cleansing as an affirmation that their body is casting off toxins. This can be misleading as the lack of food can cause these same sensations. Consider that the body’s priorities undergo a massive shift when it stops eating. In some cases, symptoms of chronic ailments might abate, especially those that might be due to previous poor eating habits, food-related allergies or sensitivities. But there is no reason to assume that these feelings are due to actual healing or a removal of toxins.
There is an ongoing dynamic turnover of most cells in the body; they tend to be continually broken down and remade. While all this is going on, the body acts to eliminate whatever toxins it can. While it might seem reasonable to think that fasting might hasten the rate at which toxins are shed, the opposite might actually be the case. Some toxins get stored in the body’s adipose (fat) tissue, and during a fast, the body’s fat stores are used to supply needed energy. This can actually increase the toxins roaming around the body, but the rate at which the body detoxifies does not increase. When this happens, the body can experience untoward effects from the increasing blood levels of the noxious agents. And then, the lack of food might hamper the immune system at it attempts to detoxify and eliminate.
Some cleansing products claim that the toxins build up in the intestines and colon, and by using cleansing laxatives and stimulants, you force those stubborn toxins out of the body. Consider that the cells that comprise the lining of the intestines are shed periodically, which means that the lining of your intestine changes from month to month. This places on dubious footing the concept that caked-on toxins are able to hang around and wreak havoc with your health. It also casts doubt on the efficacy of the “cleanse.”
If there is a potential benefit to these processes, it might be that they can serve as a jump-start to a lifestyle change. One could use a fast or a cleanse to, in effect, cast off the past and change to a more healthful lifestyle, physically, emotionally and spiritually. The fast or cleanse can serve as a time of contemplation, where one considers the status quo and redefines the new quest for a quality of life.
Ed Blonz, Ph.D., is a nutrition scientist and an Assistant Clinical Professor at the University of California, San Francisco.
He is the author of “Power Nutrition” (Signet, 1998).
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