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Climate change worsens nutrition, studies find

By Chukwuma Muanya, Assistant Editor   |   16 March 2017   |   4:16 am

Climate change could shrink the mineral and protein content of wheat, rice and other staple crops

• Shrinks mineral, protein content of wheat, rice, other staple crops
• New material regrows bone as derived hormone suppresses appetite in mice

Mounting evidence suggests that climate change could shrink the mineral and protein content of wheat, rice and other staple crops. This means that a lunch plate piled high with food from plants might not deliver the same nutrition toward the end of this century as it does today.

An international research group announced online February 21 in Proceedings of the National Academy of Sciences that selenium, a trace element essential for human health, already falls short in diets of one in seven people worldwide.

Earlier studies link low selenium with such troubles as weak immune systems and cognitive decline. And in severely selenium-starved spots in China, children’s bones don’t grow to normal size or shape. This vital element could become sparser in soils of major agricultural regions as the climate changes.

Also, scientists from Harvard University, Samuel Myers and Peter Huybers and collaborators, warned in a paper published online January 6 in the Annual Review of Public Health that zinc and iron deficiencies could grow as micronutrients dwindle in major crops worldwide,

Meanwhile, a team of researchers repaired a hole in a mouse’s skull by re-growing “quality bone,” a breakthrough that could drastically improve the care of people who suffer severe trauma to the skull or face.

The research was published in the journal PLOS One.The work by a joint team of Northwestern University and University of Chicago, United States, researchers was a resounding success, showing that a potent combination of technologies was able to regenerate the skull bone with supporting blood vessels in just the discrete area needed without developing scar tissue – and more rapidly than with previous methods. Injuries or defects in the skull or facial bones are very challenging to treat, often requiring the surgeon to graft bone from the patient’s pelvis, ribs, or elsewhere, a painful procedure in itself. Difficulties increase if the injury area is large or if the graft needs to be contoured to the angle of the jaw or the cranial curve.

But if all goes well with this new approach, it may make painful bone grafting obsolete.In the experiment, the researchers harvested skull cells from the mouse and engineered them to produce a potent protein to promote bone growth. They then used Ameer’s hydrogel, which acted like a temporary scaffolding, to deliver and contain these cells to the affected area. It was the combination of all three technologies that proved so successful.

Also, according to mouse studies conducted by Columbia University Medical Center (CUMC) researchers, hormone secreted by bone cells can suppress appetite. The hormone – called lipocalin 2 – turns on neurons in the brain that have been previously linked to appetite suppression. The findings reveal a previously unknown mechanism for regulating the body’s energy balance and could lead to new targeted therapies for the treatment of obesity, type 2 diabetes, and other metabolic disorders.

The study was published online in the journal Nature.Meanwhile, Myers reported February 16 at the Climate and Health Meeting held in Atlanta, United States (U.S.) that futuristic field experiments on wheat and other major crops predict that more people will slip into nutritional deficits late in this century because of dips in protein content.

Winkel and colleagues concluded that by the end of the century, about two-thirds of heavily cultivated agricultural land would probably lose selenium under an intermediate scenario of climate change. With a projected average end-century warming of 2.2 degrees Celsius compared with 1986 to 2005, selenium drops in breadbasket regions in the study by an average of 8.7 percent. Only 19 percent of croplands seem likely to gain selenium.

Myers and colleagues reported in journal Nature in 2014 that zinc and iron concentrations in crops, too, would probably shift as climate changes. They analyzed harvest samples from a total of 41 cultivated varieties of major crops (wheat, rice, field peas, soybeans, maize and sorghum) grown with the expensive and elaborate experimental protocol known as FACE, for Free-Air CO2 Enrichment. In Australia, Japan and the United States, test crops grew in outdoor fields within futuristic Stonehenge circles of skinny ducts blowing extra carbon dioxide to mimic mid- to late-century atmospheres.

Sites varied, but at the time, researchers reported their baseline carbondioxide (CO2) as 363 to 386 parts per million and pushed their pipes to deliver 546 to 586 ppm.

Based on samples from these far-flung experiments, the researchers found iron concentrations in wheat dropped an average of five percent. Zinc levels fell nine percent. Most other crops showed a tendency toward declines too, although maize and sorghum, which use what’s called the C4 pathway for carbon capture, showed signs of possible resilience.

Then Myers asked: “So what?” Myers and colleagues put together an epic database of how much of 95 foods people eat in 188 countries around the world, and then calculated where the relatively modest downturns of zinc would put people at risk in the future. The researchers reported in 2015 that nutrient changes by 2050 would push about 138 million more people into zinc deficiency and for more than two billion people already zinc deficient, future crop declines could make their health problems even worse.

They said the shortfall could be especially hard on women and children. “Too little zinc raises pregnant women’s risks of premature delivery and can doom children to poor weight gain and growth. A robust immune system needs adequate zinc, and public health specialists blame 100,000 child deaths a year on immune responses so enfeebled by skimpy zinc that children couldn’t fight off pneumonia or diarrhea,” the researchers wrote in ScienceNews.




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