U.S. Study Reveals How Exercise Protects Memory and Shields the Brain from Aging
A recent study conducted by researchers at the University of California San Francisco has uncovered a precise biological mechanism explaining how physical exercise enhances cognitive abilities and protects memory from decline.
The findings show that physical activity strengthens the brain’s natural defense system by preserving the integrity of the blood-brain barrier — a protective structure made up of a tightly connected network of blood vessels that prevents harmful substances in the bloodstream from entering brain tissue. As people age, this barrier tends to weaken, increasing the risk of chronic inflammation and cognitive disorders associated with Alzheimer’s disease. Understanding this mechanism represents a key step in combating brain aging.
The discovery centers on an enzyme produced by the liver known as “GPLD1.” Scientists observed higher levels of this enzyme in mice that engaged in regular physical activity. However, a scientific puzzle remained: GPLD1 is a large molecule that cannot cross the blood-brain barrier to directly reach brain cells.
The new study, published in the journal Cell, reveals that the enzyme’s effects begin outside the brain — specifically at the blood vessels surrounding it. This finding highlights a previously underappreciated connection between the body’s organs and brain health.
Researchers demonstrated that the protein “GPLD1” acts as a biological cleaning mechanism targeting another protein called “TNAP,” which accumulates on blood vessel walls with age. This buildup weakens the connections between cells and increases the permeability of the blood-brain barrier in a harmful way.
When the liver releases GPLD1 in response to exercise, it helps remove TNAP proteins from cell surfaces, restoring the strength and integrity of the blood-brain barrier. Experiments showed that mice genetically engineered to produce high levels of TNAP experienced memory decline similar to aging. In contrast, older mice regained cognitive abilities after TNAP levels were reduced.
These findings open new avenues for understanding the link between exercise and brain health and may pave the way for future therapeutic approaches targeting the same biological pathway to protect memory from age-related decline.
