Gluten. I can think of no other protein that has gotten so much bad press in the last decade. Justified or not? Read on, and let me know what you think.
Celebrity authors and credible authorities alike have increasingly taken a stand against gluten. The result is a nationwide anti-gluten movement, in which gluten-free (GF) products are flying off supermarket shelves at record -- perhaps in some experts' eyes consumers are overreacting -- to these claims.
An estimated 100 million Americans consume GF products in a year, meaning about one in three are trying GF products in the U.S. This drives the $2 billion annual market for these products.
The GF craze is so profound it's easy to believe gluten may indeed be the lynchpin in our chronic illness epidemic. The message seems to be: Just remove gluten and your symptoms will vanish along with your excess pounds overnight.
But does science truly support this idea? Is gluten really the problem? And does removing it from the diet work for everyone and guarantee good health?
To find the answer, let's turn to recent research on this controversial protein.
I think the truth will surprise you.
How Is Wheat Intolerance Different From Celiac Disease?
Celiac disease (CD) is an autoimmune disease whereby gluten protein peptides trigger an immune response that injures the small intestinal lining and has dozens of adverse effects throughout the body. Non-celiac gluten sensitivity (NCGS), CD and wheat allergy (immunoglobulin E (IgE)-mediated) have similar symptomatology, however wheat allergy (WA) and CD are mediated by the immune system and diagnosed by blood testing and intestinal biopsy.
In contrast, the currently accepted criteria for a diagnosis of NCGS requires reproducible symptoms when gluten is consumed and improvement upon abstinence. The typical presentation of NCGS is a combination of gut symptoms (diarrhea, abdominal pain), and systemic features such as headache, arthralgias, numbness, chronic fatigue, eczema, anemia, and can sometimes include behavior disturbances and depression. These symptoms of NCGS typical appear hours to days after ingestion whereas WA is more immediate -- beginning within minutes and up to two hours after ingestion.
Patients with NCGS typically lack the classic CD serological and biopsy findings. However, there is growing evidence that they may suffer from derangements in gut permeability, inflammation and immune reactivity to gluten.
How Common is NCGS?
First let's examine how the prevalence of CD has shifted. Although experts agree that the prevalence of CD is 1:133 in the U.S., the prevalence of CD appears to have risen. The prevalence of CD in those over the age of 50 appears to have doubled since 1998 and a study that examined stored blood samples from 9,133 U.S. Air Force recruits (1948-1954) revealed that undiagnosed CD was four times less common in those recruits than it is today. Before we speculate why CD is rapidly on the rise let's examine what is known about NCGS epidemiology.
NCGS is most commonly seen in middle-aged females and its prevalence ranges from 0.63-6.0 percent of the U.S. population.
Why Is Intolerance to the Golden Grain on the Rise?
As Dr. William Davis brilliantly describes in his book Wheat Belly the source, digestibility, gluten content and processing of wheat has radically shifted over the years, likely leading to intolerance.
One of the most popular theories is that the chemical glyphosate, the active ingredient in the herbicide, Roundup, may be an important factor in this epidemic. Fish who are exposed to glyphosate develop a CD-like illness disrupts the gut microbial balance in animals favoring the growth of disease-inducing pathogens.
Another possible contributor to NCGS are amylase trypsin inhibitors (ATIs), which are plant-derived proteins that protect the wheat plant against infection by parasitic microbes. ATIs comprise 2-4 percent of wheat protein, their activity is seven-fold higher in modern hexaploid wheat and feeding at levels consumed by humans provokes autoimmunity in mice.
Finally, gluten-rich grains are highly fermentable and can cause gut distress in those with gut bacterial imbalances.
Collectively, CD, WA, NCGS are not uncommon, but that doesn't mean they affect everyone. So should everyone on the planet go GF? Aside from cost are there other downsides to going GF?
There is growing evidence that getting rid of wheat and gluten from the diet lowers bifidobacteria, which play a critical role in gut immune function and weight regulation.
Thus, you may want to enrich your diet with foods that bolster your friendly gut flora if you eat GF.
There is on final point I'd like to make about GF living: It isn't inherently healthier. Eating GF cookies, crackers, and cakes that contain little fiber and are packed with sugar is unlikely to help you achieve your health and weight goals. Take a skeptical eye to them.
But, of course, not all grains contain gluten. So what about the rest of the whole grain family? These too have come under increasing scrutiny of late. Do any whole grains have a place in the human diet?
I'll take this issue up in my next blog and explore whether or not whole grains are all they are cracked up to be.
References
Fasano, Alessio, et al. Non-celiac Gluten Sensitivity. Gastroenterology (2015). 2015, Jan 9. pii: S0016-5085(15)00029-3. doi: 10.1053/j.gastro.2014.12.049. [Epub ahead of print]
Hollon, J., et al. Effect of gliadin on permeability of intestinal biopsy explants from celiac disease patients and patients with non-celiac gluten sensitivity. Nutrients. 2015. 7(3): 1565-76.
Tapia-Rubio, A., et al. Increased prevalence and mortality in undiagnosed celiac disease. Gastroeterology. 2009. 137(1):88-93.
Davis, W. Wheat Belly: Lose the Wheat, Lose the Weight, and Find Your Path Back to Health. Rodale Books. New York.
Shehata, AA., et al. The effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. Curr Microbiol. 2013. 66(4):350-8.
Sanz Y. Effects of a gluten-free diet on gut microbiota and immune function in healthy adult humans. Gut microbes 2010;1:135-7.