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Is genetically modified wheat causing increases in gluten issues?

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Updated April 23, 2013

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Is genetically modified wheat causing increases in gluten issues?

Is GMO wheat to blame for the rise in celiac disease?

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Question: Is genetically modified wheat causing increases in gluten issues?

There's no question that celiac disease is on the rise, and non-celiac gluten sensitivity may be, as well. But is genetically modified wheat — also known as GMO wheat — to blame?

Answer:

No, genetically modified wheat is not to blame for the hikes in celiac and gluten sensitivity ... for the simple reason that GMO wheat simply isn't being grown commercially (yet).

To be considered genetically modified, a plant such as wheat needs to have its genome altered through gene splicing in the laboratory. Scientists who genetically engineer crops are looking to introduce a desirable trait into that crop, and they do so by inserting a new gene sequence from another species into the target crop's genome.

For example, biotechnology giant Monsanto Co. created its GMO soybeans by introducing a gene sequence from a specific bacterium, Agrobacterium sp. strain CP4, into soy's genome. This bacterium gene allows the soybeans to resist repeated applications of the herbicide Roundup (also produced by Monsanto). Between 80% and 90% of soy grown in the U.S. is GMO Roundup Ready soy.

Monsanto, which in 2004 abandoned efforts to develop Roundup Ready wheat, said in 2011 that it was again experimenting with genetic engineering in wheat ... this time, to produce drought-resistant and higher-yielding wheat strains. Competitors — notably, Syngenta AG and BASF Global — also are pursuing GMO wheat.

However, no GMO wheat products are being marketed yet. And that means (contrary to popular belief) that GMO wheat cannot be blamed for increased celiac and gluten sensitivity cases.

Hybridized Wheat May Be To Blame, Though

That doesn't mean wheat hasn't changed over the last half-dozen decades, though — it has, as the result of a process called hybridization. And some scientists (although not all) say those changes could be one cause of an increased inability to tolerate gluten.

In hybridization, scientists don't tinker directly with the plant's genome. Instead, they choose particular strains of a plant with desirable characteristics, and breed them to reinforce those characteristics. When this is done repeatedly, successive generations of a particular plant can look very different from the plant's ancestors.

That's what's happened with modern wheat, which is shorter, browner and far higher-yielding than wheat crops were 100 years ago. Dwarf wheat and semi-dwarf wheat crops have replaced their taller cousins, and these wheat strains require less time and less fertilizer to produce a robust crop of wheat berries.

Dr. William Davis, author of the anti-wheat best-selling book Wheat Belly, raises questions in his book about whether these changes in wheat have caused the spike in gluten-related health problems, including obesity and diabetes. "Small changes in wheat protein structure can spell the difference between a devastating immune response to wheat protein versus no immune response at all," Davis writes. Modern wheat has been bred to contain more gluten, he says.

However, a study published in 2013 in the Journal of Agricultural and Food Chemistry cast doubt on part of Davis' hypothesis when it reported that there's not really any more gluten in modern wheat than there was in 1920s-era wheat.

So What's Really Going On?

That's not clear. Studies do show a significant increase in the incidence of celiac disease over the last several decades. Anecdotally, gluten sensitivity also is rising, although there haven't been any studies to confirm that (and some blame the current trendiness of the gluten-free diet for reported increases).

Donald D. Kasarda, the U.S. Department of Agriculture scientist who authored the 2013 study on 1920s wheat, says it's possible that increased consumption of wheat in recent years — rather than increased gluten in the wheat actually consumed — might be in part to blame for increased incidence of celiac disease. He also says the use of wheat gluten as an ingredient in processed foods might contribute.

However, no one really knows why celiac disease (and possibly gluten sensitivity) might be affecting more people. There's one thing that's certain, though: genetically modified wheat can't be to blame.

Learn more:

Sources:

Davis, William. Wheat Belly. Rodale Press, 2011.

Kasarda DD. Can an increase in celiac disease be attributed to an increase in the gluten content of wheat as a consequence of wheat breeding?. Journal of Agricultural and Food Chemistry. 2013 Feb 13;61(6):1155-9. doi: 10.1021/jf305122s. Epub 2013 Jan 31.

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