Fight Aging!

As is true of excess weight, the raised blood pressure appears to have a lower threshold for causing long-term harm to health than is commonly thought. Negative effects increase as blood pressure increases, but the point at which harms start is surprisingly close to normal blood pressure ranges. More aggressive control of blood pressure via antihypertensive drugs and lifestyle changes produces benefits even when pushing it back down into what the normal range. The boundary at which raised systolic blood pressure is considered to be a problem, veering into the territory of hypertension, was recently lowered by ten points.

There are any number of mechanisms by which raised blood pressure causes harm. It accelerates the onset and progression of atherosclerosis. It increases the pace at which small blood vessels rupture in the brain, where neural tissue is not effectively repaired once so damaged. It helps to disrupt the blood-brain barrier and other aspects of endothelial function. Thus it isn't to surprising to note the correlations between blood pressure and later life cognitive function, and between lifestyle choices that affect blood pressure and later life cognitive function, as in today's open access paper.

Mean arterial pressure, fitness, and executive function in middle age and older adults

Physical activity and associated gains in fitness have been shown to be neuroprotective for older adults, with evidence suggesting preserved brain structure, function, and better cognitive functioning. Many recent meta-analyses suggest that exercise interventions and subsequent gains in fitness may have a selective effect on cognition in older adulthood, with the greatest impact on executive functioning. Some evidence suggests that changes in executive function may be occurring earlier in middle age and may be predictive of future cognitive decline. Therefore, there is a need to examine how fitness may be related to executive function across a younger adult sample.

Cardiorespiratory fitness (CRF) is a measure of the ability of the circulatory and respiratory systems to deliver oxygen, and the peak rate at which oxygen can be consumed, during sustained physical activity at a maximal effort. Higher CRF has been shown to be related to greater brain volume, particularly in gray matter regions like the prefrontal cortex. Higher CRF has also been associated with preserved white matter integrity, and functional connectivity, as well as better cognitive functioning in older adults. However, the mechanisms underlying these positive effects are not fully understood.

The purpose of the current study was to examine whether mean arterial pressure (MAP) mediated the association between CRF and executive function in middle age and older adults. Participants were adults (age 40+) without any self-reported psychiatric and neurological disorders or cognitive impairment from the Nathan Kline Institute Rockland Sample (N = 224, M age = 56). CRF was defined by V̇O2max estimated via a bike test, neuropsychological testing was used to examine executive functioning, and MAP was calculated from systolic and diastolic blood pressure recordings. Mediation models were analyzed controlling for age, sex, and education.

Results indicated that higher CRF was associated with better inhibition and there was a significant indirect effect of greater CRF on better inhibition through lower MAP. There were additional significant indirect effects of greater CRF and better fluency and planning through lower MAP. This suggests that MAP may be an underlying physiological mechanism by which CRF influences executive function in mid- and older adulthood.