I need to jump in on the gluten posts series. [Editor's Note: "Dr. Mark Hyman Indicts Gluten," "Dr. Daniel Amen Identifies 5 Brain Patterns of Overeaters," "9 Ways Gluten Goes Undercover" and "Dr. William Davis Warns of Gluten"]
I have a problem with the incrimination of gluten as a major cause of obesity or even as a major health problem. I’ve read (with consternation) Dr. William Davis’ book, Wheat Belly. He starts off with evidence that in certain schizophrenics wheat consumption may induce opioid effects, yet the effect is mild, and it has been documented only in schizophrenics. Dr. Davis then jumps to the conclusion that wheat is addictive and causes obesity, and further he lumps gluten enteropathy with this, in an incrimination of wheat for the entire population.
Gluten enteropathy definitely causes celiac disease, but the prevalence is quite low. The recent claim that gluten punches holes in the gut, exposing the immune system to toxic antigens and inducing total body inflammation is not accepted by mainstream medicine.
Dr. Davis — along with Dr. Hyman and Philip Werdell — also claims that wheat is addictive because digestion converts the starch to sugar, which is absorbed into the bloodstream. Sugar has been found to be addictive in rats. However, Volkow & Wise (2005) concluded that food addiction appears to be a sensory addiction. In contrast to drugs, which activate the reward system through direct pharmacological effects, pleasurable food activates the system through fast sensory signals, as well as slow processes, such as rising brain glucose.
Actually, simple sweet taste has been shown, in more than a hundred studies, to calm infants and children during uncomfortable procedures (Harrison et al., 2012; Miller et al., 1994).
Kristjan Gunnarsson, in his Kris Health Blog, discusses how wheat glutens form opioid peptides:
“I believe that humans are able to become addicted to these substances. The process often starts in childhood, when kids are rewarded with candy when they behave well, contributing to psychological dependency as well. Judging from the above studies and personal experience, I think it is highly likely that junk food causes addiction in the brain of many people, causing them to become unable to change their diet despite wanting to.”
Nevertheless, similar to William Davis, Kristjan Gunnarsson is lumping sugar and junk food addiction together with gluten opioid peptides.
Few of the young people posting or responding to polls on Weigh2Rock.com and few of the 87 obese youth in our two app studies have mentioned bread or other wheat products as problem foods. Rather it is candy, soda, chips, ice cream, french fries, and other fast food with which they have the biggest problem. And the foods they eat in excessive amounts at meals hardly include bread or wheat products. Excessive amounts of fatty meats, potatoes and fried foods like chicken strips are where most of their calories at meals come from.
To summarize, the gluten thing may be another ploy to obfuscate the fact that it is mainly excessive amounts of ANY food that’s responsible for obesity. Nearly all the 87 obese youth in both of our two pilot studies reported that consumption of large food amounts at meals (at home) was the main contributor to their overweight. Likewise, reducing amounts at meals contributed the most to their weight loss, but was much more difficult than avoiding problem foods and eliminating snacking. Most of the obese youth in our study became overtly upset when asked to reduce food amounts at meals, and several dropped out of the study rather than do so. Thus, instead of incriminating specific constituents of food as the cause of obesity, we should look at why people consume large amounts in the first place, and keep doing so, even though they are aware that it will result in further weight gain. Using food as a coping mechanism would seem to be the culprit, in my humble opinion.
1) Problem food addiction seems to be a sensory addiction (taste, texture, “mouth feel”) rather than a direct narcotic effect on the brain by certain food ingredients. For example, bulimics vomit up consumed foods, yet are still addicted to the foods. And, as previously noted, Volkow & Wise (2005) concluded that in contrast to drugs, which activate the brain’s reward system through direct chemical effects, pleasurable food activates the system mainly through sensory signals.
2) From results of our two studies, excessive food amounts consumption appears to be a different type of addiction, probably a behavioral addiction similar to nail biting, rather than the classic addiction (cravings) of problem foods. And, consumption of excessive food amounts likewise does not appear directly related to action of food ingredients on the brain. Instead, it seems to be the mechanical action of eating (biting, chewing, swallowing) that the individual is hooked on. However, consumption of excessive food amounts is facilitated by food sensations (taste, texture). Snacking is similar. Both typically do not involve specific foods but rather whatever food is available, though the food has to be palatable (not hyperpalatable). I recall a post from a mother on our site lamenting that she had removed all junk food from her house, yet her obese daughter then binged on apples!
Harrison, D., Beggs, S., & Stevens, B. (2012). Sucrose for procedural pain management in infants. Pediatrics, 130(5), 918-925.
Volkow, N. D., & Wise, R. A. (2005). How can drug addiction help us understand obesity? Nature Neuroscience, 8(5), 555-560.