Sachin Rustgi, a researcher at South Carolina’s Clemson University, is working to rehabilitate gluten, a food component that has fallen out of favour and even spawned a multi-billion dollar market for gluten-free products.
Rustgi was one of nearly 900 delegates from more than 50 countries around the world who gathered in Saskatoon for the first International Wheat Conference in Saskatoon in July.
Gluten makes dough stretchy and elastic, trapping tiny gas bubbles from yeast to make soft, spongy, delicious bread.
For people with celiac disease, about one person in a hundred according to Health Canada, gluten is not good.
For celiacs, eating gluten means painful cramping, bloating, damage to the small intestine, and other long-term effects such as osteoporosis and infertility.
While the bad-boy reputation of gluten has created new market opportunities for gluten-free products and made life much easier for people with celiac disease, Rustgi said there are disadvantages. These products are often higher in fat, salt and various carbohydrates such as sugars. There is also evidence that by removing whole grain fibre from the diet, gluten-free diets can increase the frequency of more serious problems.
“The reason is you remove the good bacteria that ferment the fibres to produce a myriad of beneficial compounds such as antioxidants,” Rustgi said. “So you change the entire microbiota in the gut, and then you introduce new bacteria as well as yeast, like candida, and that increases your vulnerability to disorders like colon cancer.”
From a nutrition perspective, a gluten-free diet also means products made from wheat, rye, and barley are off the table. Whole grains take up a quarter of the “plate” under the new Canada Food Guide. They provide crucial nutrients such as iron, folic acid and other key vitamins.
“Truly speaking, no solution is perfect,” Rustgi said. “Going gluten free is also not perfect. I always appeal in all my presentations: if one does not know medically that you require it, do not go gluten free.”
Because of the health benefits of whole grains, it’s still attractive to develop wheat with friendlier gluten. It helps that gluten is not a single food component, Rustgi explained. Rather, it is a combination of proteins called glutenins and gliadins.
“Not all the gluten proteins are essential for baking properties,” Rustgi said. “What we were trying to do is remove gliadins and low molecular weight glutenins, that is, the ‘bad gluten’ with poor digestibility and unbalanced amino acid composition. These are actually the major culprits for celiac disease, and what is required for baking is high molecular weight glutenins.”
Rustgi explained that when the “bad gluten” is removed from the grain, the plant compensates by making more high molecular weight glutenins or other seed proteins. This yields a grain that is more nutritionally balanced. It is packed with essential amino acids, for instance, which are otherwise lacking in gluten.
Rustgi and his colleagues developed strains of wheat with more than 76 percent of the offending proteins removed.
Getting there has been a challenge, as it requires modifying the genetics of wheat and raises the marketing spectre of having the material labelled GM by regulatory agencies. Because of this, they opted to use new methods that either use microscopic carbon nanotubes or magnetic nanoparticles to deliver gene-editing substances to pollen grains to modify the genetics of the wheat.
“These pollen-based methods are very similar to what we do in regular breeding,” he said. “You put the pollen with the magnetic nanoparticles or carbon nanotubes, coated with DNA carrying the genes of interest, and they automatically get into the cells. You take that pollen and you do the cross-fertilization that you do in regular breeding.
“It’s all very similar to the natural system, and carbon nanotubes, they degrade with time. So it’s inert and it’s natural. To my mind, they’re one of the best methods available to us at the moment.”
Despite this care, Rustgi said consumers are still leery of any form of genetic modification of wheat. The situation is made worse unapproved transgenic wheat popping up in unexpected places. A herbicide-tolerant wheat developed in 2004 was never released to market, but it has shown up in isolated spots in Oregon and Washington state in the years since.
Such cases can have far-reaching consequences. In 2015, a dozen transgenic red spring wheat plants found on an access road in southern Alberta temporarily shut down Canadian wheat exports to Japan.
While the regulators work out the GM angle, Rustgi continues to develop wheat lines with improved gluten profiles. This includes testing them against human sensitivity and baking actual loaves – the ultimate test of a good bread wheat.
Like many researchers, Rustgi is reluctant to assign a timeline to his work, but hopes that varieties will be field-ready within five to six years.
Facts about celiac disease
- Celiac disease is a genetic autoimmune disease that damages the villi of the small intestine and interferes with absorption of nutrients from food.
- About one percent of the population has celiac disease, which can affect men and women of all ages and races.
- There are no pharmaceutical treatments or cures for celiac disease. A 100% gluten-free diet is the only existing treatment for celiac disease today.