Mechanisms of cognitive decline, one of the greatest threats of aging

There is a lot being written about the ability of the brain to compensate for age-related changes with enhanced connectivity and efficiency that makes for better judgment and emotional maturity. The sad truth is that the brains of at least 50% of us will have sustained too much damage for this to come to fruition. The authors of an extensive review just published in the journal Nature begin with a statement important for anyone reading this:

"Cognitive frailty is emerging as one of the greatest health threats of the twenty-first century. As the life expectancy of the population has increased, so too has the prevalence of cognitive decline and dementia, largely in the form of Alzheimer's disease, which now affects almost 50% of adults over the age of 85 in the United States1. This startling figure can only grow as the average age of the population rises, so understanding the basis of cognitive decline during ageing is critical."

They proceed to describe some of the major categories that define the process of molecular aging as it pertains to cognitive decline, noting that:

"...altered regulation of fundamental mechanisms of ageing may contribute to the pathogenesis of neurodegenerative disorders."

It is this kind of attention to fundamental mechanisms with a systems biology perspective that is inherent to the functional medicine approach. The authors identify these major factors:

1. Mitochondrial dysfunction (the ability of brain cells to produce energy to function and repair)
2. Oxidative damage
3. Epigenetic changes (changes in genes due to environmental stimuli)
4. Autophagy and protein turnover (housecleaning)
5. Insulin signalling

Additionally, they describe the role of the brain as the master regulator of aging throughout the body.Their list is not complete—there are additional factors that we attend to including neurotransmitter metabolism and receptor sensitivity, fatty acid cell membrane integrity, the role of steroid hormones in the brain, autoimmune inflammation, excess cortisol (stress hormone) production, etc. If you want to be realistic about a strategy for preventing cognitive decline and Alzheimer's disease, these are the kinds of things that you have to ask you doctor about and make sure they are being attended to.