Intelligent people tend to have a longer life expectancy. Is this because they also tend to have more education, be wealthier, and make better lifestyle choices? This web of correlations is hard to untangle. Might there also be underlying physical mechanisms that contribute to this well known association between intelligence and long-term health, however? Are more intelligent people a little more physically robust, on average? There is some evidence for this sort of effect to be present in other species, and some genetic studies suggest that common variants affect both traits, while twin studies also add evidence in favor of physical mechanisms that influence both intelligence and longevity.
Here, researchers argue that variations in mitochondrial function is the mechanism of greatest interest in this matter, as this can affect the energy-hungry tissues of both brain and heart muscle. Mitochondria are the power plants of the cell, packaging chemical energy store molecules to power cellular processes. It is well known that mitochondrial function is important in aging, and declines with age. If an individual has a slightly more efficient mitochondrial population, or mitochondria that are just a little more resilient to the molecular damage of aging, perhaps that will be enough for both improved brain function throughout development and adult life, and a slower decline into age-related disease and mortality.
For over 100 years, scientists have sought to understand what links a person's general intelligence, health and aging. In a new study, scientists suggest a model where mitochondria, or small energy producing parts of cells, could form the basis of this link. This insight could provide valuable information to researchers studying various genetic and environmental influences and alternative therapies for age-related diseases, such as Alzheimer's disease. "There are a lot of hypotheses on what this link is, but no model to link them all together. Mitochondria produce cellular energy in the human body, and energy availability is the lowest common denominator needed for the functioning of all biological systems. My model shows mitochondrial function might help explain the link between general intelligence, health, and aging."
The insight came while working on a way to better understand gender-specific vulnerabilities related to language and spatial abilities with certain prenatal and other stressors, which may also involve mitochondrial functioning. Mitochondria produce ATP, or cellular energy. They also respond to their environment, so habits such as regular exercise and a diet with fruits and vegetables can promote healthy mitochondria. "These systems are being used over and over again, and eventually their heavy use results in gradual decline. Knowing this, we can help explain the parallel changes in cognition and health associated with aging. Also with good mitochondrial function, the aging processes will occur much more slowly. Mitochondria have been relatively overlooked in the past, but are now considered to relate to psychiatric health and neurological diseases. Chronic stress can also damage mitochondria and that can affect the whole body - such as the brain and the heart - simultaneously."