Wheat has been a staple of the human diet for thousands of years, but when the healthfulness of modern wheat varieties was called into question, Oklahoma State University researchers went to work to study its impact on gut health.
As many as 3 million Americans consume gluten-free diets annually, according to a 2017 Forbes article, but only a small proportion have a diagnosed medical condition, such as celiac disease, that actually requires such a diet. While reasons for going gluten-free vary, a common concern cited by many is the gluten protein found in modern wheat varieties.
To test whether modern wheat causes an inflammatory response in the GI tract, Drs. Edralin Lucas, Brenda Smith and Brett Carver designed a study to compare the effects of heirloom wheat variety Turkey and modern wheat variety Gallagher while monitoring the immune response, body weight and changes in the integrity of the GI tract.
“We were trying to answer the question, ‘How does the 90 to 95 percent of the population without a diagnosed gluten-sensitive condition respond to these different types of wheat?’” said Smith, an OSU Regents Professor of Nutritional Sciences and John and Sue Taylor Endowed Professor in the College of Education and Human Sciences.
Carver, an OSU Regents Professor and leader of OSU’s Oklahoma Wheat Improvement Team in the Ferguson College of Agriculture, said the varieties selected are important in American agricultural history. German Mennonite migrants introduced the Eastern European Turkey variety to the U.S. Great Plains in the 1870s after varieties from the East Coast performed poorly. By the 1940s, Turkey was the most popular wheat variety in the region, and approximately 99.9 percent of modern U.S. wheat varieties trace their origins to Turkey.
Gallagher, popular for its pest resistance, is a descendant of Turkey and has replaced it as one of the most commonly grown wheat varieties in the Great Plains, Carver said. It is found in products ranging from pizza to cereal but contains 33-mer, an indigestible gluten peptide that some believe heightens gluten sensitivity.
“When these concerns first came out, scientists as a whole were not talking,” Carver said. “This is the first study published like this. We’re not just confirming something that’s hypothesized or already published. No, this is groundbreaking.”
Could digestibility in the modern wheat variety Gallagher have changed from its heirloom ancestor Turkey? To test these concerns, laboratory mice were fed Turkey or Gallagher wheat as part of either an “optimal” mice diet or a Western (high fat, high sugar) diet.
“From an inflammatory standpoint, there was really no difference between the two varieties,” Smith said.
The mice fed the heirloom wheat showed slightly lower levels of LPSbinding protein, an indicator of inflammation. Meanwhile, mice on the modern wheat diet showed improved structure of villi, finger-like projections in the small intestine that absorb nutrients.
“In terms of some of the structural components of the gut, the modern wheat actually provided a benefit and some improvements,” Smith said.
While past research has considered topics related to gluten sensitivity, such as the impact on individuals with celiac disease consuming wheat, Smith said this is one of the first studies directly researching the gastrointestinal impact of wheat consumption in a mouse model that mimics a Western diet.
Individuals with celiac disease often exhibit what Smith calls a “leaky gut,” as the body detects wheat as an invader and attacks the lining of the digestive system, causing microorganisms or their nutrients to leak into the rest of the body and elicit an immune response. A lesser, but similar, similar situation can occur several hours after consuming a highfat Western meal.
“We had to give a nod to the fact people don’t eat the perfect diet,” Smith said. “With half of the animals fed a Western diet, the question was, ‘Does wheat make the response to a high fat diet worse?’ From an inflammatory standpoint, there really was no difference at all.”
In fact, mice fed a Western diet with either variety of wheat saw a reversal of one effect commonly observed in a Western diet. Short chain fatty acids, important for cell energy and immune response, are typically reduced in Western diets. However, coupling a Western diet with Turkey or Gallagher reversed this effect.
Even in the “optimal” diet, with healthy sugar and fat levels and standard mice chow, mice health improved when either wheat variety was added.
“There were some parameters, like gut barrier integrity, that actually improved by incorporating wheat into the diet, whether it was Gallagher or Turkey,” Smith added.
To measure the strength of the gut lining, or what researchers call gut barrier integrity, Smith, Lucas and Carver observed the proteins providing scaffolding between cells. While most were similar between mice consuming Gallagher and Turkey, one was actually enhanced in mice consuming Gallagher, an indicator of improved gut barrier strength.
The team has presented the results to the American Society of Nutrition, and it was published in the Journal of Agricultural Food and Chemistry. Many agriculture industry leaders are showing interest in the research.
“This should be a message to the general public, but it’s also a message to clinicians,” Smith said. “One study doesn’t turn the whole tide, but at least it should raise a question: ‘Is recommending gluten-free kinds of diets or avoiding wheat products to otherwise healthy individuals the best thing to do?’”
Their research could have major impacts. Smith said some studies have suggested severe gluten restriction causes a harmful immune response. Even in less severe situations, wheat is an important source of nutrients such as iron, selenium and fiber that would need to be replaced if wheat was removed from the diet.
Therefore, researchers are diligently sharing their findings with professional organizations including health professionals and organizations such as the Home Baking Association, the Oklahoma Academy of Nutrition and Dietetics and the Oklahoma Wheat Commission to educate the public. Smith says they especially hope to reach dietitians and personal trainers since these are the populations the public often turn to for dietary recommendations.
“The best way to get that message out is not to just talk to the public in mass, but to talk to the ones who talk to the public,” Smith said. “They are highly influential on our diet.”
While many without diagnosed medical conditions may claim to feel better after avoiding wheat and gluten, Smith said their research suggests the blame does not belong on modern wheat gluten.
“They may be feeling better by eating less processed food, and it just so happens a lot of your processed food was wheat-derived,” Smith said.
Dr. Edralin Lucas, an OSU professor of nutritional sciences and the Jim and Lynne Williams Endowed Professor in the College of Education and Human Sciences, is already looking toward future studies, especially transitioning from a study in mice to human test subjects.
“We were looking at the integrity of the gut, the integrity of immune cells and other health outcomes,” Lucas said. “But there are many opportunities for future research. For example, what is the effect of consuming these varieties of wheat in prediabetic and overweight individuals?”
As researchers collaborate with professional organizations to carry the message of their findings, Smith also highlights the importance of their own collaboration.
Carver, recognized as “Mr. Wheat” by the Oklahoma Wheat Growers Association, built on decades of wheat research expertise to help Smith and Carver trace wheat lineages and even mill and process the Gallagher and Turkey wheat flour for these studies on campus. Meanwhile, Lucas and Smith provide the shared valuable nutritional science expertise to study its effect on gut health.
“This highlights the strength of partnerships,” Smith said. “To have someone who is an expert on wheat grown in this region and couple it with our expertise on the health side is what makes this work.”
The research is funded by the Oklahoma Wheat Commission.
“That’s the beauty of a land-grant university like this,” Carver said. “Our work is going from producers and growers to health outcomes and then to the public.”
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