SUNDAY, MAY 31, 2009
"Hey buddy, wanna buy some exorphins?"
Dr. Christine Zioudrou and colleagues at the National Institutes of Mental Health got this conversation going back in 1979 with their paper,
Opioid peptides derived from food proteins: The exorphins. LINK: _http://www.jbc.org/cgi/reprint/254/7/2446
The results presented here have shown that peptides with morphine-like activities, which we call exorphins, can be isolated from some food proteins after treatment with the stomach proteinase, pepsin. Since the opiate assays which we have used so far are performed with cell homogenates or isolated organ preparations, it seems pertinent to ask whether these findings have physiological significance. Although an unequivocal answer to this question must await the results of whole
animal experiments, a number of less direct lines of evidence is presently available. In order for exorphins to function as opioid peptides in the central nervous system in vivo they must:
(a) be produced in the gastrointestinal tract
(b) survive degradation by intestinal proteases
(c) be absorbed, without degradation, into the bloodstream
(d) cross the blood-brain barrier and thereby reach central opiate receptors
(e) interact as opiates with these receptors.
The conditions of the digestion of gluten or casein with pepsin used in this work, namely 0.1 M HCl at 37°C for 1 h, are similar to conditions to which such proteins may be subjected in the stomach after a meal containing wheat or milk products. Thus, in all likelihood, exorphins will be produced normally in the stomach. The exorphins which we have studied are resistant to the intestinal proteinases trypsin and chymotrypsin. Thus, the exorphins may be expected to survive extensive degradation in the intestine. Some peptides are now known to be absorbed, without prior degradation, from the gastrointestinal tract into the bloodstream. Perhaps, most pertinent to the present studies is the work of Hemmings et al. (18, 19) which showed that, after feeding of I-labeled gliadin to rats, labeled peptides, which retain the ability to react with anti-gliadin antibodies, are found in appreciable amounts both in the blood and the tissues of the animals. Significantly, such peptide material was found in the brain as well.
Thus, some peptide fragments of gluten do indeed reach the brain. Direct evidence that the exorphins will do so is not yet available, although some peptides have been shown to cross the blood-brain barrier (20). Finally, we have presented evidence that the exorphins will bind to brain opiate receptors as well as to those of peripheral organs. In summary, exorphins may normally reach opiate receptors in the central nervous system and trigger their function (Zioudrou, Streaty and Klee; 1979).
Exorphins are exogenously-derived peptides (i.e., short amino acid sequences obtained from outside the body) that exert morphine-like properties. Mimicking the digestive process that occurs in the gastrointestinal tract using the gastric enzyme, pepsin, and hydrochloric acid (stomach acid), Zioudrou et al isolated peptides from wheat gluten with morphine-like activity. They followed this research path because of the
apparent association of wheat and mental illness. LINK: _http://www.ncbi.nlm.nih.gov/pubmed/16423158
Abstract: OBJECTIVE: Schizophrenia affects roughly 1% of the population and is considered one of the top 10 causes of disability worldwide. Given the immense cost to society, successful treatment options are imperative. Based on initial findings, gluten withdrawal may serve as a safe and economical alternative for the reduction of symptoms in a subset of patients. METHOD: A review of the literature relevant to the association between schizophrenia and celiac disease (gluten intolerance) was conducted. RESULTS: A drastic reduction, if not full remission, of schizophrenic symptoms after initiation of gluten withdrawal has been noted in a variety of studies. However, this occurs only in a subset of schizophrenic patients. CONCLUSION: Large-scale epidemiological studies and clinical trials are needed to confirm the association between gluten and schizophrenia, and address the underlying mechanisms by which this association occurs (Kalaydjian, Eaton, Cascella, and Fasano; 2006).
In the bioassays used, wheat-derived exorphins competed successfully with the endogenous opiate, met-enkephalin. Interestingly, casein-derived (i.e., casein milk protein) exorphins were also identified that also displayed opiate-binding activity, though less powerfully. The morphine-like activity was also blocked by the drug, naloxone (the same stuff given to people exposed to morphine overdose).
Among the many devastating effects of celiac disease , the immune disease that develops from wheat gluten exposure, are mental and emotional effects, such as anxiety, fatigue, mental "fog," depression, bipolar illness, and schizophrenia, that disappear with removal of gluten. Many parents of autistic children also advocate wheat-free diets for similar reasons.
Among the many wonderful comments posted on the last Heart Scan Blog post, "I can't do it," was Anne's:
I am not the Anne in your post, but I was addicted to wheat. It was my favorite food. I lived on and for breads. Then I discovered I was gluten sensitive and I did go through a withdrawal of about 4 days. After 4 days I noticed my health problems were disappearing. Depression, brain fog and joint pain are 3 of the many symptoms that disappeared. That was 6 yrs ago.
Tell Anne that I had dreams about bread in the beginning - they will pass. Now the donuts, breads, cookies and cakes in the stores and at work don't even look good. In fact, I don't like the smell of bread anymore. It takes time, but the cravings do pass.
Combine wheat"s exorphin-driven addictive potential with its flagrant blood sugar-increasing properties, and you have a formula that:
1) makes you fat
2) increases likelihood of diabetes, and
3) makes you want to keep on doing it.
Reminds me of nicotine.
My personal view: I have absolutely no remaining doubt that wheat products have no place in the human diet. Not only does the research provide a plausible basis for its adverse health effects, but having asked hundreds of people to remove it from their habits has yielded consistent and remarkable health benefits.
