Greater Fitness and Blood Vessel Elasticity Correlates with Slower Cognitive Decline

The quality of the vasculature is an important determinant of the pace of aging in the brain. There are probably several distinct processes involved, all of which tend to correlate with one another as aging progresses. Firstly the brain is an energy-hungry organ, but the network of tiny capillaries in tissues becomes less dense with age. A consequently lower supply of nutrients to cells causes loss of function. The same result may also occur due to the age-related weakening of the muscles of the heart. Secondly, blood vessels lose their elasticity in later life, and this in turn causes a rise in blood pressure as feedback mechanisms run awry. Higher blood pressure causes damage to sensitive tissues in many organs through a variety of means, such as a greater rate of rupture or blockage of tiny blood vessels. The brain of an older individual is riddled with the minuscule scars left by these events, and that damage adds up. Why do blood vessels grow stiff with age? A mix of underlying causes, not all of which are fully understood. Persistent cross-links that our biochemistry cannot break down glue together structural proteins of the extracellular matrix, altering the structural properties of tissue. Rising inflammation and signals from senescent cells contribute to both calcification of blood vessel walls and dysfunction in the smooth muscle cells responsible for contraction and dilation. The behavior of smooth muscle is more responsive to lifestyle circumstances than ot...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs