Gluten: what does the science say?

What is gluten?

Gluten is a type of protein that’s found in wheat, rye, barley and foods made from these grains. It gives elasticity to baked goods, and provides that chewy texture. Gluten in made of two smaller proteins, called gliadin and glutenin. Gliadins and glutenins are the two main components of the gluten fraction in wheat.

Does present-day wheat have more protein (and gluten) than ancient wheat?

The grain composition of present day wheat varieties is very similar to ancestral wheat varieties. A 2014 study from the University of Saskatchewan examined the literature regarding changes in wheat protein concentrations produced by Western Canadian bread wheat lines developed during the last 85 years. They found no increased protein content in modern lines, and noted that normal protein variations (from 11-15% protein) are only attributed to yearly fluctuations in environmental conditions.

In a related study of 37 wheat varieties dating from 1860 to present, varieties showed an average 0.01% per year increase in grain protein concentration, which accounted to only 1% increase over a century (Hucl et al. unpublished). A preliminary examination of gluten in 10 wheat varieties introduced from years 1860 to 1994 also disproved a chronological change in subunit profiles.

Is gluten now somehow harmful to humans because wheat has changed over the years?

Gluten, a protein found in wheat, barley, rye and other grains, must be avoided by 1 percent of the population with celiac disease, and perhaps another 6 percent with gluten intolerance. There is no scientific evidence that either wheat or gluten are harmful to the health of anyone who does not have one of these conditions. In fact, whole grains like wheat are recommended as part of a balanced diet and associated with a reduced risk of heart disease, obesity, type-2 diabetes, dementia and other health conditions.

A recent study from the University of Saskatchewan looked at wheat seeds since 1860 and showed that they have not changed. Further, genetically modified wheat does not exist in the marketplace. Since no commercial wheat is genetically modified, and there have been no changes to wheat’s DNA or core protein content.

Is it true that the wheat’s gliadin protein acts like an opiate, causing wheat-based foods to be addictive?

No. This claim is based on a 1979 study that found many common foods such as wheat, milk, rice and even spinach produce the same effect on the human brain. The study focused on small fragments of proteins known as peptides believed to be responsible for this effect. It is an area that deserves more study as it remains unclear that peptides are absorbed when consumed intact in wheat-based food.

Is a gluten-free diet (if you aren’t celiac or gluten-sensitive), a good way to lose weight?

The gluten-free diet is meant for people who have an allergy or intolerance to wheat or gluten. There is no scientific evidence to link wheat or gluten to weight loss. Weight problems are not the fault of one food (or in this case one specific protein found in some foods); it’s total diet and lifestyle that matter.

Some people who eliminate gluten from their diet will lose weight, because they will no longer be eating cakes, cookies, pastries and baked goods, and their usual fast foods like pizza, burgers and pasta are no longer easily accessible. It’s not the gluten that helps with weight loss, it’s the reduction of total calories, sugar and fat. You can simply cut back on these foods to lose weight without totally eliminating gluten from the diet.

Gluten-containing whole grains, such as barley, rye and whole grain wheat, are part of a healthy diet, even when trying to lose weight. To date, 14 cross-sectional studies have found that ~3 daily servings of whole grains is associated with lower body mass index in adults. And a study on 74,000 women over a 12 year period shows women who consumed more whole grains and whole wheat consistently weigh less than those who ate less of these fiber-rich foods, and were 49% less likely to gain weight compared to those eating foods made from refined grains.

Why do so many people say they feel better after going gluten-free?

For 1 percent of people with celiac disease and about 6 percent of people with gluten sensitivity, eliminating gluten will help relieve uncomfortable symptoms such as gas, bloating, headaches and diarrhea. These people are feeling relief, because they have finally found an answer to their digestive problems. It’s great if people who have struggled with undiagnosed celiac or gluten intolerance for years finally find something that works for them – and that’s true of about 5-10 per cent of our population.

But, people who do not have these symptoms or these medical conditions do not need to remove gluten from their diet. About 25 percent of consumers report buying gluten free foods, many needlessly. They may not understand that GF is meant for people with certain health conditions – not for the entire population. And, GF foods are often more expensive, less healthy (more sugar, refined ingredients, fat and salt) and more processed than other staple foods.

 

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