Climate change is pumping our food full of carbs
I last studied botany more than 50 years ago so I cannot tell if the reasoning below is right or not. But it sounds possible. The question to ask, however, is "So what?" If some of our food has a higher calorie count it hardly matters to us -- given the "obesity epidemic". We already eat to excess and calorie counting is an accepted way to counter that.
But what about poor countries? Having more carbohydrates in their food should help them avoid hunger. So long live carbohydrates!
I have lost contact with the latest diet fads but I think refined sugar is now the villain. Carbohydrates have been rather praised in some eras. I suspect they are seen as good now too
The claim that having more carbohydrates in your food is a "nutritional decline " rather bamboozles me. All food is nutrition. They seem to assume that only some rare elements in food are nutrition, which is rubbish
It could be, as claimed, that increased carbs drive out other nutrients but, if so, where is the evidence that the effect is strong enough to matter to human health?
OF ALL THE INSULTS that greenhouse gases hurl at our food supply—a warming climate that triggers more severe droughts and floods in key agriculture regions like the Midwest and California, declining yields of staple crops—the most insidious may involve the deterioration of the nutritional quality of plants we eat.
That’s the startling message of growing research led by Irakli Loladze, a mathematical biologist with joint appointments at the Bryan College of Health Sciences in Nebraska and Arizona State University.
Ever since we started burning massive amounts of coal three centuries ago, atmospheric carbon dioxide concentrations have nearly doubled. Plants are very flexible in their chemical composition, Loladze says. When the air that surrounds plants is richer in CO 2, they use it to synthesize more carbohydrates, including starches and sugars, which they store in their cells. These carbs dilute other beneficial molecules, including protein and some vitamins and minerals. This has no harmful effect on the plants themselves, which “aren’t the least concerned about the quality of our nutrition. We eat them—we’re kind of their enemies,” Loladze says.
For people, this nutritional decline could be life-changing. Consider your breakfast toast. The bread’s wheat contains lower levels of protein than the wheat that people were consuming decades ago, Loladze says, citing a 2004 study led by Lewis Ziska, then a Department of Agriculture researcher. Every bite of toast delivers more carbs and less protein. Other studies show lower quantities of essential minerals such as calcium, magnesium, iron, and zinc.
What’s true for humans is also true for the animals that rely on plants. And the deficit moves up the food chain, from the rabbit nibbling on weeds to the bobcat eating that rabbit. The effect has already shown in cows, which gobble up grasses with declining nourishment. For a 2017 study, researcher Joseph Craine, along with Texas A&M and University of Maryland scientists, compared cattle dung samples taken between 1994 and 2015 from pastures across the country. The grasses showed a nearly 10 percent decrease in protein over the time range, enough to cause the cattle to gain weight more slowly. To compensate for the protein gap, beef producers would have had to spend an extra $1.9 billion on soybean feed to supplement the animals’ diet, the scientists calculated—added pressure for cash-strapped ranchers.
If you haven’t heard about this, you’re not alone. President Donald Trump’s agriculture department has hardly trumpeted the studies. In a 2018 paper, Loladze and a team that included the usda’s own researchers found that increasing CO 2 concentrations had diminished the nutritional quality of rice, causing significant drops in protein, iron, and zinc, as well as vitamins B1, B2, B5, and B9. Rather than sound the alarm about the decline of a crucial staple crop, the usda declined to publicize it and tried to convince the University of Washington not to either, as Politico’s Helena Bottemiller Evich reported in June. In Trump’s usda, Loladze says, there’s an “implicit directive not to promote agriculture research related to climate change.”
What’s to be done, given that global carbon emissions show no sign of dropping anytime soon? Currently, farmers are rewarded for total output, not for the amount of nutrients in their crops. “If we want to make our food more nutritious, we should change the incentives,” Loladze says. “We should start paying farmers for quality.”
Research into farmers’ best chances for counteracting the dilution effect remains in its infancy. But scientists from the United Kingdom have hit upon a possible solution for wheat. The scientists identified wheat strains that are especially good at developing a symbiotic relationship with common soil-dwelling fungi. The wheat plants give the fungi some of the carbon dioxide they suck from the air, in exchange for nitrogen and phosphorous, key elements for plant growth. The symbiosis means less reliance on fertilizers—a core driver of climate change—but also potentially less carbon, and thus carbs, diluting the nutrients of the wheat. Sounds like a line of inquiry that the usda should pursue and publicize if its climate denial fever ever breaks.