Mitochondria are the powerhouses of our cells, and they are vital to our survival because they generate ATP, which gives us energy using the food we consume. This process is called cellular respiration. Mitochondria also generate heat, store calcium for cell signaling functions, and mediate cell growth and death.
When your mitochondria malfunction, your cells are starved of energy. Depending on the type of cell, the subsequent symptoms can vary significantly. Typically, the cells that use the largest amounts of energy, like heart muscle cells, are impacted the most by dysfunctional mitochondria. Dysfunction in mitochondrial DNA is a key factor in diseases associated with aging such as Alzheimer’s disease and type 2 diabetes. In addition, it is a key factor in autism, schizophrenia, chronic fatigue syndrome, and bipolar disorder.
What are mitochondria?
Mitochondria are microscopic, bean-shaped organelles with two membranes, an outer membrane that covers the organelle and contains it like a skin, and an inner membrane. The inner membrane is folded into cristae, which increases the surface area available for chemical reactions to take place. The fluid contained in the center of the mitochondria is called the mitochondrial matrix. The matrix includes the D.N.A. of the mitochondrial genome and the enzymes of the tricarboxylic acid (TCA), which metabolizes nutrients into by-products the mitochondria can use for energy production.
The structure of mitochondria changes continuously through fission, fusion, and morphology. This makes it very difficult to count the mitochondria of a cell at any given time.
How many mitochondria are in a cell?
The number of mitochondria in a cell varies widely by cell type. For instance, liver cells can have over 2,000, whereas mature red blood cells have no mitochondria. Cells that use high amounts of energy have more mitochondria than other cells. Close to 40% of the cytoplasm in heart muscle cells is comprised of mitochondria.
The number of mitochondria can change continuously. Cells may have more mitochondria during phases of active growth, production of digestive enzymes, transportation of materials into the cell, or other types of movement. They may display decreased numbers of mitochondria during periods of quiescence.
How is mitochondria size regulated?
The mitochondrial network is comprised of dynamic cellular organelles that have the ability to change shape, size, and position within seconds. Many of these changes are a result of mitochondria fission, which is the division of a single organelle into 2 or more independent organelles, and fusion, which is the opposite function. They occur synchronously and continuously in many cells of your body. It is the balance between fission and fusion that determines the structure of the mitochondria. Maintaining the optimal size of the mitochondria is crucial for cell health and longevity.
Mitochondrial fusion is critical for the maintenance of mitochondrial function. It allows the spreading of mitochondrial D.N.A. throughout the mitochondrial compartment, which optimizes mitochondrial function and prevents the accumulation of mitochondrial mutations during aging. In addition, it acts as a “rescue” mechanism that prevents the elimination of damaged mitochondria by mitophagy. A blockage of mitochondrial fusion results in a loss of mitochondrial membrane potential.
Mitochondrial fission, on the other hand, plays an essential role in mitochondrial replication and the removal of damaged organelles by selective autophagy.
When the processes are imbalanced, such as an absence of fission, the fusion results in the creation of mitochondrial nets with limited tubular ends. This may happen because of an inadequate supply of the regulating protein, called dynamin-related protein 1 (Drp1). Too much Drp1 spurs excessive mitochondrial fission and an excessive number of short mitochondria. Both situations cause mitochondrial dysfunction, which can play a role in a wide array of diseases that affect nearly all organs and tissues of the body. This includes neurodegenerative diseases like Parkinson’s and Alzheimer’s as well as neurodevelopmental disorders.
Fission and fusion create a large diversity of mitochondrial shapes. They may be looped structures, sausage string shapes, rods of various lengths, and multiple branched networks. The numerous shapes are related to the function of the cells.
How you can support your mitochondria
The mitochondria are critical for life. However, they are susceptible to nutrient deficiencies, environmental toxins, and oxidative damage. You want to be proactive and take care of them. To work efficiently, mitochondria need to be resilient. Resilience is built through the action and stimulation of mitochondria by hormetic stressors, including exercise, calorie restriction, extreme cold and heat exposure, red and near-infrared red-light exposure, hypoxia, U.V. light, Xenobiotics (like caffeine, nicotine, alcohol, and other drugs) as well as dietary phytonutrients.
Diet & intermittent fasting
A diet rich in a variety of plant phytonutrients provides the essential micronutrients the body needs for energy production as well as acting as an antioxidant and hormetic stressor responsible for reducing inflammation and initiating mitochondrial growth and biogenesis (the creation of new individual mitochondria). Plant phytonutrients include polyphenols such as:
- resveratrol in red grapes
- sulforaphane in broccoli
- curcumin in turmeric
- E.C.G.C. in green tea
- epicatechins in cacao
- ellagic acid in pomegranates
- carotenoids in tomatoes
- anthocyanins in berries
Although eating a healthy diet is critical for mitochondrial health, when you eat and how you eat can also affect mitochondrial function. Calorie restriction and time-restricted feeding (TRF) (or intermittent fasting) help optimize mitochondrial function and extend their lifespan.
The mild stress placed upon the body by not eating enough acts as a hormetic stressor and activates a wide variety of protective pathways within the body, ramping up anti-inflammatory and antioxidant defenses.
Carb cycling is also a form of hormesis, and carbohydrate restriction produces ketone bodies, which may have many protective effects. Ketone bodies are an energy-efficient source of fuel. They produce more ATP than glucose. Using ketone bodies for energy decreases the production of free radicals and lowers inflammation, which can cause severe disease and damage. Ketogenesis improves mitochondrial health by activating the Nrf2 pathway and increasing mitochondrial biogenesis.
Exercise
Movement has an important effect on neurotransmitters that regulate wakefulness. When you sit around a lot during the day, your body thinks it is time to rest and will start preparing for sleep. Sitting and inactivity can lead to a decrease in the number and health of mitochondria, thus slowing down metabolism over time. Exercise signals your body to wake up. Even small, simple actions such as taking short movement breaks and walking more will provide benefits.
Supplements
Though eating a healthy, phytonutrient-rich diet, exercising regularly, and getting good quality sleep are vitally important for improving energy levels, it is often difficult to do while balancing the demands of life. This is where supplements can play an important role. Studies have shown that combinations of supplements can significantly reduce fatigue and other symptoms associated with mitochondrial damage and can naturally restore mitochondrial function.
Nutritional therapeutics like phospholipid complex and astaxanthin support the mitochondrial membrane. They play a role in preventing damage to the mitochondrial membrane from oxygen radicals and replacing/repairing damaged membrane tissues. Lipid therapy has proved very effective at reducing fatigue. In one study, oral administration of specific nutritional therapeutics for 12 weeks resulted in a 35% reduction in tiredness and a 26% increase in mitochondrial function.
Other supplements can assist with biological, chemical reactions in the body. These can be vitamins, minerals, or coenzymes that work synergistically with enzymes in the production of ATP and include magnesium, coenzyme Q10, B vitamins, L-carnitine, creatine, and D-ribose.
Supplements that protect the mitochondria and activate mitochondrial biogenesis are also useful adjuncts to a healthy lifestyle. Indian gooseberry, turmeric, alpha-lipoic acid (A.L.A.), and green tea are potent antioxidants that prevent/reduce oxidative damage and decrease inflammation in the mitochondria. Another supplement, PQQ, or pyrroloquinoline quinone, works synergistically with the master antioxidant glutathione to support mitochondrial function.
The ability of cells to produce energy is directly related to the ability of mitochondria to convert the energy from food into reduced nicotinamide adenine dinucleotide (NADH) and transfer electrons from NADH to the electron transport chain and eventually produce ATP. However, the amount of N.A.D. in your body naturally falls with age, which may impair biological functions important to health and contribute to age-related diseases. It’s believed that increasing N.A.D. through supplementation may improve symptoms and/or delay these conditions. Citrus bioflavonoids, resveratrol, quercetin, N-acetyl-cysteine (N.A.C.), and niacin or nicotinamide all act as precursors that boost levels of NAD+.
Final thoughts
Mitochondria generate most of your cell’s energy in the form of adenosine triphosphate (ATP). They vary in size, shape, and structure. Their numbers may vary depending on the type of cell they are in. Mitochondrial fission and fusion determine their size and shape.
As mitochondria are so critical for health and energy production but are also susceptible to nutrient deficiencies and damage, you want to nourish them. You can do this with good lifestyle habits, eating a healthy, phytonutrient-rich diet and exercising regularly, intermittent fasting, and supplements as well as limiting environmental toxins, intermittent fasting.