MITOCHONDRIA, AGING, AND HOW TO EXTEND YOUR LIFE One emerging concept in the still unfolding investigation of the root causes of aging is that the failure of mitochondria is central.
It goes like this.
The mitochondria are the power plants of each cell in your body.
It is inside these double membrane bound organelles that fatty acids, amino acids (protein) and pyruvate (sugar) are burned (oxidized) to make ATP.
ATP is the energy currency inside the cell.
This burning produces reduced molecules (NADH) whose energy is used to pump hydrogen ions into the inter-membrane space which then flow back into the mitochondrial matrix through a large transmembrane protein to generate ATP.
This process is mediated by five electron transport proteins attached to the inner surface of the mitochondrial membrane.
The largest electron transporter is ubiquinone oxoreductase or C1.
Ubiquinone, a major component of this complex is also called co-enzyme Q-10.
CoQ10 is produced in the liver by a series of steps, one of which is the same step blocked by statin drugs.
As such I recommend all my statin patients supplement with CoQ10.
That electron transport chain is very efficient at passing electrons eventually to the oxygen we breath in to form water and carbon dioxide.
But some electrons do leak out and react with anything they bump into to form free radicals or reactive oxygen species (ROS).
These ROS can catalyze chain reactions in DNA and proteins leading to cumulative damage over time.
Now mitochondria are unique in that they carry their own DNA and therefore most of the genes needed by the mitochondria are housed in the mitochondrial matrix.
So this DNA is particularly susceptible to damage by those ROS.
But mitochondria also use novel means to maintain their DNA.
It turns out that they fuse together and then divide again in a regulated way.
In a poorly understood process, damaged mitochondrial DNA is selectively packaged in smaller mitochondria which are then tagged for recycling by the cell.
But if a mitochondrion is damaged or degrades spontaneously, it releases proteins which trigger enzymatic degradation of the chromosomal DNA causing the entire cell to die (apoptosis).
Younger mitochondria are small and uniform and damaged DNA is tagged for destruction.
Older cells have enlarged mitochondria and accumulate damaged DNA which often leads to unregulated lysis eventuating in the death of cellsl (aging).
Now the good news, animal studies show that simple strategies to keep your mitochondria healthy can help ward off many diseases of aging including type 2 diabetes, heart disease, Alzheimer's disease, Parkinson's disease, and even many cancers.
It has been shown that overloading this electron transport chain with sugar or fat leads to excess ROS generation.
The root of type 2 diabetes (insulin resistance) may be mitochondrial dysfunction due to poor diet.
Therefore external stimuli such as exercise and caloric restriction are well known to revitalize senescent mitochondria in animals and humans.
Supplementation with antioxidants, especially R-Lipoic Acid and acetyl-L-carnitine (ALCAR) has been shown to revitalize aging mitochondria and cognition in old rats.
And it seems clear that early supplementation may actually slow the aging process.
As you read this, many researchers are investigating new therapeutic agents which may allow us to dramatically slow the aging process or even put the brakes on it.
So while we wait for the fountain of youth to be made available, perhaps doing what we can do now to keep our mitochondria happy will pay off.
Future therapies may allow humans to attain consistently long disease free lives in the near future.
To your health, Dr Z