Healthexcel System of Metabolic Typing
Arctic natives have DNA built for warmth
Their cells produce more heat, scientists say
Image: Igloo
Kevin Frayer / AP file
An Inuit man works on a traditional igloo in Iqaluit, the capital of the Canadian territory of Nunavut. Scientists say Far North peoples like Canada's Inuit have evolved to survive in colder climates.
The Associated Press
Updated: 12:07 p.m. ET Jan. 09, 2004

WASHINGTON - People native to the far north evolved to produce more heat in their cells, a new study says. The researchers suggest this change is a climate-driven effect.

The change occurs in the mitochondria, the parts of human cells that burn fuel to produce heat and energy, according to the team of researchers led by Eduardo Ruiz-Pesini of the University of California at Irvine.

The scientists analyzed mitochondria from 1,125 people ranging from Africa to Europe and Arctic Siberia. They found that that mutations in mitochondria DNA, increasing production of heat, though reducing energy production, rise in people living closer to the pole, compared with tropical residents.

The change results in an increased propensity for energy deficiency diseases, but also in increased longevity and resistance to aging, they report in Friday’s edition of the journal Science.

“Our observations support the hypothesis that certain (mitochondrial DNA) variants permitted humans to adapt to colder climates,” the researchers concluded.

The variants continue to produce differences in energy production and affect health, they said.

DNA provides the blueprint for the development of the body, combining information from the separate DNA of each parent. However, mitochondrial DNA directing the energy production in cells is inherited only from the mother, unlike the DNA that provides the body’s primary set of instructions for operation.

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