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 (which is different from genetic engineering). And some scientists (although not all) say those changes could be one cause of an increase in the number of people who have an 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 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.
而且：Hard wheat has more gluten than soft wheat, and the gluten it contains is stronger than gluten found in soft wheat.
Interestingly, despite the difference in gluten between American and European wheat, rates of celiac disease between the two regions are identical, with 1 in 133 people believed to suffer from this gluten-related autoimmune disease。
在自认Non celiac gluten sensitive的消费群体里有市场。这些人试过后感觉不错就是回头客了。
只要在地里种GMO, 就会传播，不管多小心。所以20多年后， 现在没有人知道到底GMO麦子在美国有多普遍。你更不可能知道！
“Field trials and approvals
As of 2013, 34 field trials of GM wheat have taken place in Europe and 419 have taken place in the US. Modifications tested include those to create resistance to herbicides, create resistance to insects and to fungal pathogens (especially fusarium) and viruses, tolerance to drought and resistance to salinity and heat, increased and decreased content of glutenin, improved nutrition (higher protein content, increased heat stability of the enzyme phytase, increased content of water-soluble dietary fiber, increased lysine content), improved qualities for use as biofuel feedstock, production of drugs via pharming and yield increases.
As of December 2017, no GM wheat had been approved for release anywhere in the world.
The transgenic wheat that was furthest developed was Monsanto's MON 71800, which is glyphosate-resistant via a CP4/maize EPSPS gene. Monsanto received approval from the FDA for its use in food, but withdrew its EPA application in 2004, so the product was never marketed. It also received approval for use as food in Colombia.
Studies conducted by Monsanto showed that its nutritional components are equivalent to nontransgenic commercially available wheat, and animal studies that have used MON 71800 for feed have confirmed this. Environmental Risk assessments have been conducted by Monsanto, and government regulatory agencies have approved its use in food;
However, farmers were worried about the potential loss of markets in Europe and Asia due to public refusal of the end-product, so Monsanto withdrew its EPA application for Roundup-Ready Wheat.
In 2010 Monsanto's partner in India, Mahyco, announced that it planned to seek approval to market GM wheat in India in the next three to five years.
The Argentina-based company Bioceres developed a genetically modified wheat variety claiming to withstand drought while providing farmers with high yields. But as of 2019 this GM variety isn't approved yet because of risks for trade: export markets may not accept it.
In 1999 scientists in Thailand claimed they discovered glyphosate-resistant wheat in a grain shipment from the Pacific Northwest of the United States, even though transgenic wheat had never been approved for sale and was only ever grown in test plots. No one could explain how the transgenic wheat got into the food supply.
In May 2013 a strain of genetically-engineered glyphosate-resistant wheat was found on a farm in Oregon. Extensive testing confirmed the wheat as a variety – MON71800. The wheat had been developed by Monsanto but never been approved or marketed after the company had tested it between 1998 and 2005. The unexplained presence of this type of wheat presents a problem to wheat growers when buyers demand GMO-free wheat. Japan subsequently suspended import of soft white wheat from the United States. A Kansas farmer sued Monsanto over the release, saying it had caused the price of wheat grown in the US to fall. Monsanto suggested that the presence of this wheat was likely an act of sabotage. On Jun 14, 2013, the USDA announced: "As of today, USDA has neither found nor been informed of anything that would indicate that this incident amounts to more than a single isolated incident in a single field on a single farm. All information collected so far shows no indication of the presence of GE wheat in commerce." As of August 30, 2013, while the source of the GM wheat remained unknown, Japan, South Korea and Taiwan had all resumed placing orders, and the disruption of the export market was minimal.
The investigation was closed in 2014 after the APHIS had exhausted all leads but had not found any evidence that the wheat had entered commercial supply.
In 2019, the USDA announced that genetically modified wheat plants engineered to resist Roundup were detected in an unplanted field in Washington state.“
可美国的大米也有问题，含砷高。特别是brown rice 。 所以我尽量买国内或泰国进口的大米。国内的大米多半含铅和镉较高。但这两种重金属对成年人来讲，没有砷坏。砷是致癌的。 美国卖的short grain差不多都是美国产的。香米很多是进口的