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Brain benefits of exercise can be gained with a single protein: Findings open door to drugs that could help protect the aging brain -- ScienceDaily

The new study, published July 9, 2020 in Science, showed that after mice exercise, their livers secrete a protein called Gpld1 into the blood. Levels of this protein in the blood correspond to improved cognitive function in aged mice, and a collaboration with the UCSF Memory and Aging Center found that the enzyme is also elevated in the blood of elderly humans who exercise regularly. But the researchers showed that simply increasing the amount of Gpld1 produced by the mouse liver could confer many of the same brain benefits as regular exercise.