On the surface, the benign-looking wheat plant would seem a very simple thing. And yet, upon its reedy stalk rests a complicated, little understood, vastly important and, if you fall in the gluten-free category, a potentially bloat-inducing food source.
Last week week, the international teams tackling the massive job of sequencing the wheat genome announced the launch of the next phase of work
in France, a project that will sequence the 4B chromosome (one of 21 such chromosomes in bread wheat, 11 of which are already underway or completed) and take approximately two years to complete. The bread wheat genome is immense – roughly five times the size of the human genome – and although as much as 80% of it consists of repeated sequences, it’s nevertheless a job that stretches the boundaries of current technologies.
These efforts to sequence the bread wheat genome are founded upon a global need for more food. Bread wheat accounts for the vast majority of wheat produced, which is a food staple for 35% of the world’s population. The World Bank has called for a 60% increase in wheat production by 2050
in order to meet rising demand. Meeting this need will require a greater understanding of genetic factors that affect yields, such as growing time, grain size and quality, and resistance to pests and climate events.
Paradoxically, a specialist with the Canadian Wheat Board indicated that bread wheat crops planted in the prairies this spring were lower than normal
, due mainly to price predictions.
But crop prices and consumer demands are more fickle than what the World Bank might wish or what might be in humanity’s best interest over the long term. Given the current demand for gluten-free foods – a market that is predicted to be valued at $15 billion US next year
– it’s tempting to draw a connection between it and a decline in prices for grains that contain gluten. As is evidenced by Jimmy Kimmel’s comic “man on the street” question to LA’s health conscious denizens
, a gluten-free diet is often more about fad and fashion than science or medicine, with notable exceptions for the roughly 1% of the population with celiac disease or the smaller number with a true wheat allergy.
In terms of complexity and our overall understanding, we appear to be on much firmer footing with the genomics project than we are in comprehending the nuanced reasons why so many people are on a gluten-free diet. Whether non-celiac gluten sensitivity (NCGS) symptoms are real, imagined, or related to something else entirely -- science has yet to come down firmly on that score (there are many conflicting studies
, often with sample sizes too small
to be significant) – there is ample room and need for more research, such as what genomics may yet reveal.
One such line of research seeks place our knowledge of currently farmed varieties of Canadian Western Red Spring wheat in context with what was planted in the past. In Saskatchewan, a team of researchers has catalogued changes in wheat characteristics and composition dating back to 1860, roughly the time when the varietal “Red Fife” was introduced to the Canadian prairies. Over a 19 year study period, 37 varieties of historic and modern wheat were planted, representing the most common varietals cultivated in the prairies in each decade from 1860 to 2000. The team was able to track significant changes in the types and qualities of wheat used, including stalk height, density and size of fruit, and average time to harvest. The first findings were published in May
, complementing similar work that had been conducted in the US and elsewhere.
In essence, our prairie wheats now have shorter stalks, take less time from planting to harvest, are more tolerant to pests and, significantly, produce more food mass and a better quality bread product. Of considerable interest to the media was the finding that protein concentrations in wheat have only increased by 1% since 1860, a fact that seems to defy the many claims that gluten is responsible for symptoms experienced by many with NCGS. If wheat protein hasn’t changed significantly, what has? In an article posted by the Daily Mail
, one of the study’s authors, Dr. Ravindra Chibbar, indicated that they are currently reviewing their data with an eye on starch
, the second main component of wheat grains, along with gluten.
Undoubtedly, wheat has many more secrets to share.