For the past two decades, several studies revealed mitochondria damage from oxidative stress in the process of aging (4). Mitochondria are organelles (subunits with a function) found in every cell. They are known as the powerhouses of the cells because they generate energy in the form of Adenosine Triphosphate (ATP) molecules necessary for all cell and bodily functions. Mitochondria contain DNA and are vulnerable to free radical damage.
You speak and move because mitochondria produce 90% of the energy you need from food and oxygen. ATP production helps to synthesize hormones, including dopamine and adrenaline; DNA repair enzymes; nucleic acid, and other functions.
ATP production in the brain, heart, and skeletal muscles decreases with age, which is one of the main causes of premature aging. Most ATP energy is not stored. Only approximately 85 mg is accumulated permanently in the ATP molecules for a quick run of 5 to 8 seconds before being released as calories. ATP must constantly be maintained so that there is always energy available. A healthy adult body produces the equivalence of approximately 88 and up to 143 pounds of ATP daily. A person also recycles their body weight equivalent in ATP daily.
One impressive example: In cardiac tissue, mitochondria turnover produces 700mg ATP that lasts 10 seconds, which is about 10 heartbeats. 86,000-104,000 beats/day = 6 million mg + ATP is utilized. Myocardial ATP turnover = 10,000 times/day is possible because of the production of energy from the mitochondria. This may explain the reason for heart failure when ATP is insufficient. Sadly, this is now a frequent event among young people who suddenly die from cardio-respiratory collapse in the USA, Portugal, and elsewhere. You will better understand when I explain the inherited mitochondria mutation from the mother to the child.
Heart and liver cells contain approximately 4000 mitochondria and also the highest amount of SOD and Coenzyme Q10. The quantity of energy synthesized by these two main organs reflects in health and longevity. This means that our 100 billion cells contain approximately 10000 billion mitochondria that consume 90% of the oxygen we breathe. Since they have DNA, they are independent of the nuclear cells and encode proteins involved in the process of cellular respiration.
All humans and animals depend on oxygen to survive. However, oxygen can also be a deadly corrosive gas, causing iron to crumble into rust and a cut apple to turn brown from oxidation. This is the paradox of oxygen. While it is necessary for aerobic life, it can also be a poison.
The central nervous system tissue contains a high concentration of mitochondria and undergoes a large flux of oxygen. Inevitably, mitochondria are the primary source of free radical production. Thus, they are more vulnerable to the damaging effects on mtDNA, which oxidize much faster than cells, inducing mutations associated with aging (5).
All the organs utilizing a high quantity of oxygen produce high amounts of free radicals. Mitochondria produce more free radicals than any other tissue. The brain, which requires a very high amount of oxygen for the neurons, inexorably produces the highest level of oxy-radicals and is more subject to oxidation and deterioration. Endogenous antioxidant enzymes and other nutrients from food, such as vegetables, fruits, spices, etc., help balance the production of free radicals in the mitochondria.
The mitochondria of an aged person reflect a decline in the quantity, function, and mutations that can occur since mtDNA is more vulnerable than nuclear DNA. Professor Bruce Ames, a researcher at the University of California and a world specialist in oxidative stress and mitochondria, has proven the link between oxidation and mitochondria in the aging process. In our society, about 35% to 50% of people over 35 years show a weakness in the production of ATP. At 67 years, you have 50% fewer mitochondria than at 40 years. Hence, much less ATP energy. Some people are born with fewer mitochondria and thus age faster. The more free radicals produced in mitochondria, the more they are damaged, and the less ATP energy is maintained. This decrease in seniors at 60 years contributes to difficulty moving and living alone.