Mitochondria, Muscles, and Caffeine by Jerry Brainum 9/23

 

Caffeine is the most popular ergogenic aid. It is also the most common ingredient in various "fat-burning" supplements. Unlike many other substances, caffeine has a massive research database to prove its efficacy. Although found in several natural foods, the most common source of caffeine is coffee. Indeed, besides containing substantial amounts of caffeine, coffee contains other active ingredients such as various antioxidant polyphenols that are associated with health and longevity. The most common use of caffeine is to increase alertness. It does that by blocking receptors in the brain for a substance called adenosine. Among other effects, adenosine is known to provide both feelings of relaxation as well as fatigue. From an exercise and fat oxidation perspective, caffeine promotes the release of fat stored in lipocytes, more familiarly known as "fat cells." Caffeine does that by promoting the release of catecholamines, norepinephrine and epinephrine that induce a cascade that leads to the release of stored fat. But caffeine also increases metabolism, which is an independent fat reduction effect. But some research shows that caffeine can produce still another effect that can lead to increased fat oxidation, as well as increased energy. 

This extra feature offered by caffeine is that it can promote the development of new mitochondria. Mitochondria are cellular organelles that are the site of both fat oxidation and energy production as ATP. While there are hundreds of mitochondria in each of the body's cells, unless they are fully functional, cellular health can decline. Many of the most common diseases have a mitochondrial disorder component. This makes sense since mitochondria are often called the "powerhouse" of cells since they are the source of cellular energy. Just as a car won't run without gas (unless it's an electric car) cells won't function without sufficient energy that is supplied by active mitochondria. Without sufficient working mitochondria within the cell, the cell dies out and becomes senescent. What that means is that while the cell is still there, it is no longer replicating as normal cells do. But what the senescent cell does do is release highly inflammatory substances collectively known as SASP, which stands for the senescence-associated secretory phenotype. The inflammatory chemicals that are released by senescent cells are thought to be a major cause of systemic inflammation, itself a major cause of most degenerative diseases including brain degeneration and age-related muscle loss. Senescent cells are often called "zombie cells" because they are not active but still dangerous.

A loss of mitochondria with age is also considered to be a major cause of aging. Indeed, the organs and tissues that are most energetic in the body are also those that are most affected by a loss of mitochondria. These energetic tissues include the brain, the heart, and muscles. A lot of muscle aging occurs because of the loss of muscle mitochondria. What would cause such a loss? Inactivity. The body works on . . .