Found within all human cells (with the exception of red blood cells) is the ability to produce energy—energy that enables action, maintenance, movement—and life in general. Microscopic structures called mitochondria are the key players in these processes and produce 95 percent of the cell’s energy. They dwell, sometimes in the hundreds and thousands, in a single cell. The number of mitochondria in a cell depends on how active that cell is. For example, an active brain or muscle cell may contain thousands of mitochondria, whereas a blood platelet may contain only two. Mitochondria make up 80 percent of the volume of the photoreceptors in the cone cells of the eye, again numbering in the thousands. Each mitochondrion is tailored to meet the needs of the specific type of cell it’s in. The purpose of breathing, eating, and ensuring a steady supply of fuel in the blood is fulfilled in these seemingly unnoticeable structures. Like tiny factories, they take the components of foods we eat and the air we breathe to produce energy.
Mitochondria have various functions, other than supplying energy. They also control cell growth, function, and cell death. Mitochondria do their part in detoxifying ammonia, a breakdown product of protein that can be very harmful to us. They are involved in the production of estrogen and testosterone, as well as how cholesterol is used. Mitochondria are intimately entwined with how we burn calories and what we refer to as “metabolism.”
These biochemical functions of the mitochondria are dependent upon certain supporting nutrients, some of which include B vitamins, vitamins C and E, and minerals like zinc, manganese, copper, and selenium. When these nutrients are insufficient, the mitochondrial processes don’t work as they should. Additionally, the mitochondria can become vulnerable to damage.
Mitochondria have various functions, other than supplying energy.
There is a price to pay for producing energy. Wherever there’s energy production, there are often potentially harmful by-products. This is no different in the human body, especially in the mitochondria. As energy is produced in the cell, groups of substances we have labeled free radicals and reactive oxygen species (ROS) are generated.
When unregulated, ROS can be destructive to the mitochondria. They can also promote aging and decline in mental function, such as memory loss, Alzheimer’s, and Parkinson’s disease. Thankfully, mitochondria are naturally equipped with repair mechanisms. Healthy mitochondria contain counter substances that dismantle the ROS, making them innocuous. (These substances include glutathione, SODs [superoxide dismutases], lipoic acid, and Coenzyme Q10.) Compounds such as carotenoids (found in fruits and vegetables), phytochemicals, and vitamins C and E disarm the radicals. Supporting these natural repair mechanisms is a significant part of preventing damage to mitochondria and pursuing mitochondrial repair.
ROS are not just bad guys, however, they play important roles in our physiology as well. ROS are used by the immune system for defense. They function as signaling molecules and help fight cancer. As signaling molecules in the brain, they impact cognition and memory formation.1 The key is balance and regulation. Excessive calorie intake, inadequate physical activity, and the presence of metals are some of the conditions in which lack of regulation can occur. Essentially, ROS can cause damage when exposure is prolonged and concentrations are high, but in lower concentrations, they have beneficial effects.2
We take certain medications with the intention of improving health, but they can also be toxic to the mitochondria, and/or hinder their healthy function by depleting them of important cofactors. It’s unfortunate, but mitochondrial toxicity testing is not required by the FDA for drug approval.3 Statins, for example, deplete Coenzyme Q10, a vital energy production team member. Metformin inhibits the energy-producing pathway. These medications may be needful and provide much benefit to some individuals, but it may be worthwhile to assess how to compensate the mitochondria.
As we age, mitochondrial activity is decreased and there is an increased production of free radicals. The average 70-year-old has only 50 percent of the Coenzyme Q10 that a 20-year-old has. Unfortunately, mitochondrial dysfunction is implicated in common disorders of aging, including heart disease, cancer, diabetes, dementia, migraines, weakness, fatigue, and Parkinson’s disease. A characteristic of cancer cells is the altered activity of mitochondria and how energy is produced. When cells become dangerous, it’s the mitochondria that are responsible for facilitating cell death. However, when there is mitochondrial malfunction, tumor cells metastasize rather than die. There can be various side effects from dysfunction of these mini-organs as they literally inhabit almost every cell in the body.
As we age, mitochondrial activity is decreased and there is an increased production of free radicals.
Healthy, functioning mitochondria are invaluable to us. Every attempt to take care of them will be well worth the effort. How can we keep the mitocondria mighty?
As mentioned above, certain nutrients are essential. Supplementation may be necessary for those needing extra support or those with inadequate diets. Supplements that have been used for supporting mitochondrial function include a full B vitamin complex, carnitine, a-lipoic acid (ALA), vitamin C, vitamin E tocopherols, and Coenzyme Q10 (ubiquinol and ubiquinone are absorbed better). Coenzyme Q10 is made in the cells but its production declines as we age, as mentioned above. Replacing unhealthy fats in the diet with healthy ones also supports the mitocondria.
Eating less has been found to significantly enhance mitochondrial function and reduce ROS production and mitochondrial damage. Eating less yet getting more nutrition may sound like an oxymoron until you consider how the average American eats. The key is to reduce or eliminate empty calories while consuming nutrient-dense foods and eating what we need.
Staying physically active is the best way to defy aging. Older subjects who were given high-intensity interval training, such as biking or walking at varying speeds and levels of intensity, experienced a 69 percent increase in mitochondrial capacity. Their mitochondria were becoming younger. Strength training did not yield the same results.4
A Few More Things
Avoiding toxins, staying well hydrated, and being temperate are other proven mitocondrion helpers.
Referring to God, Scripture says that “He is actually not far from each one of us, for in Him we live and move and have our being” (Acts 17:27-28, ESV). Life and movement are grounded in energy and God is the source of it all.
- K. Kishida & E. Klann, “Sources and Targets of Reactive Oxygen Species in Synaptic Plasticity and Memory,” Antioxidants & Redox Signaling, 2007, p. 233–244.
- S. Di Meo, T. Reed, P. Venditti, & V. Victor, “Harmful and Beneficial Role of ROS,” Oxidative Medicine and Cellular Longevity, 2016, http://doi.org/10.1155/2016/7909186.
- J. Dykens & Y. Will, “The significance of mitochondrial toxicity testing in drug development,” Drug Discov. Today, Sept. 2007, 777–785.
- “How exercise—interval training in particular—helps your mitochondria stave off old age,” Science Daily, March 3, 2017, https://www.sciencedaily.com/releases/2017/03/170307155214.htm.
Risë Rafferty, RDN
Risë is a Registered Dietitian Nutritionist (RDN) and has been writing and teaching about health for many years. She loves the health message and takes great pleasure in seeing people thrive by the application of its principles. Her research and down-to-earth manner allow her to offer up the health message in both an intelligent and accessible manner. She and her husband, James Rafferty, have two children.