Mitochondrial Health in Survivors How to Optimize Cellular Metabolism
Cancer survivors face a unique set of challenges. For instance, many survivors don’t feel the same sense of vitality as they did in their pre-cancer days. They also might experience persistent treatment-related side effects, or they might sense vague and subtle shifts in energy, concentration, or mood.
The bottom line is that having cancer and undergoing treatments like radiation and chemotherapy can have untoward consequences on the immune, nervous, endocrine, and other systems of the body.
These metabolic changes that cancer survivors experience are often rooted at the cellular and subcellular level. And one of the subcellular structures that has attracted the attention of cancer researchers and clinicians in recent decades is the mitochondria.
The mitochondria have long been known to play a central role in energy production, but new research shows they also fulfill numerous other essential duties. These studies show that benefits of mitochondrial health include healthy cognition and nervous-system function, cardiovascular wellness, and normal detoxification.
That’s why supporting mitochondrial function is foundational to the everyday practice of helping cancer survivors achieve a higher level of health.
What are the Mitochondria?
Mitochondria are cellular organelles that are commonly referred to as the “powerhouses” of the cell. There is truth in this moniker, as the mitochondria are responsible for producing nearly 90 percent of the body’s energy carrier—adenosine triphosphate (ATP).
Mitochondria are double-membraned organelles, with an inner matrix housing mitochondrial DNA. This type of DNA is distinct from nuclear DNA, and different in many ways. For instance, mitochondrial DNA is packaged without protective histone proteins, which partly explains the often-cited claim that mitochondrial DNA is more susceptible than nuclear DNA to oxidative damage.
The number of mitochondria in any given cell ranges from zero (in red blood cells) to more than a thousand (in liver and muscle cells). More mitochondria exist in cells that have a higher energy requirement, but energy demand is not the only determinant of mitochondrial density or function. Mitochondrial biogenesis and efficiency depend on a multitude of environmental factors, which can be modified to support optimal mitochondrial health.
Mitochondrial Functions
Mitochondria are best known for their ability to produce cellular energy (ATP). They do this via the process of oxidative phosphorylation, which is also called aerobic respiration.
In the mitochondrial matrix, the citric acid (Krebs) cycle produces reduced molecules, which are sources of electrons for the electron transport chain. This chain is the final step of energy production, involving protein complexes I through IV as well as coenzyme Q10 in the inner mitochondrial membrane. The final acceptor of electrons in the electron transport chain is oxygen (forming water).
Mitochondria fulfill a myriad of cellular functions in addition to ATP production. They participate in cell signaling, generate reactive oxygen species, modulate oxidation-reduction (redox) status, control cytosolic calcium levels, participate in cellular differentiation, and initiate apoptosis (programmed cell suicide).
It’s interesting to note that mitochondria not only begin signaling pathways to start the apoptosis cascade, but also provide a critical source of energy to effectively complete the programmed death of damaged cells.
Threats to Mitochondrial Health
One intrinsic hazard for mitochondrial health is the generation of reactive oxygen species as byproducts of cellular respiration. Oxygen is the final acceptor of electrons in the electron transport chain, and if electrons react with oxygen prematurely, superoxide free radicals are generated. Antioxidant defense systems (including the superoxide dismutase enzyme) protect the mitochondria from oxidative damage, but if these systems become overwhelmed, fragile mitochondrial DNA can be harmed.
Extrinsic threats to mitochondrial health include any influences that contribute to increased oxidative stress. High consumption of sugar or refined carbohydrates, for example, place a burden on the mitochondrial machinery, overwhelm the electron transport chain, and lead to increased production of reactive oxygen species. Radiation, chemotherapeutics, environmental chemicals, heavy metals, and cigarette smoke introduce free radicals that burden antioxidant defense systems and put the mitochondria at risk.
Because many cancer survivors have recently completed radiation or chemotherapy, they may already have a high free-radical burden. This means they may also have a greater need for mitochondrial support than the average person. The following strategies support mitochondrial health primarily by reducing oxidative stress or supporting antioxidant defenses in the mitochondria.
Clean Living for Mitochondrial Health
Mitochondria and other cellular components are exposed daily to potentially damaging compounds in our air, water, and foods.
Pesticides are one example. A 2017 study published in the International Journal of Molecular Science reported that 100 percent of nine tested pesticides induced mitochondrial changes at low concentrations, and five of the nine pesticides created significant and dose-dependent decreases in ATP production.
Medications are another example. This includes common, over-the-counter medications like Acetaminophen, which has been shown to have adverse mitochondrial effects.
Cancer survivors can also limit exposure to potentially damaging environmental compounds by making simple lifestyle changes.
Air purifiers or house plants promote better indoor air quality.
Reverse osmosis or other filtration systems remove heavy metals and other unwanted chemicals from the air in patients’ homes or workspaces.
Cleaning products should be as chemical-free as possible. Your patients can make their own products with natural and organic ingredients, or you can help them purchase “clean” cleaners.
Natural lotions, shampoos, and other personal care products can minimize chemical exposures on the skin. As with cleaning products, you can also provide access to natural and organic personal care products for your patients.
Eating for Mitochondrial Health
The mitochondria are able to use glucose, amino acids, and fatty acids as substrates for ATP production, but not all people have the same capacity to alternate between fuel sources. One indicator of mitochondrial health is the ability to easily transition between fuel sources—particularly between glucose and fat. This is known as metabolic flexibility.
When people eat too much sugar, refined carbohydrates, and processed foods, they begin to compromise their metabolic flexibility. Cells become less efficient at burning fats for fuel. And because burning glucose is less efficient and produces more free radicals than burning fats, heavy reliance on glucose contributes to more oxidative stress.
Along with avoiding foods rich in simple carbohydrates and glucose, dietary strategies to support mitochondrial health and metabolic flexibility include:
Healthy fats, including essential fatty acids from fish, nuts, and seeds. Not only are these foods an efficient fuel source for ATP production, but they’re also structural building blocks for mitochondrial membranes.
Phytonutrient-rich fruits and vegetables, which support antioxidant defense systems that protect fragile mitochondrial DNA.
Organic foods, which reduce the exposure to pesticides and other chemicals that can damage the mitochondria.
Ketogenic diets, caloric restriction, and intermittent fasting. Many clinicians recommend an overnight fast of at least 12 hours as a way to attain some of the benefits of intermittent fasting. The goal is to allow enough time for the cellular machinery to switch over to burning fats for fuel during the fast. If the overnight fast is long enough, cells are able to eliminate damaged mitochondria (a process called mitophagy) and regenerate new mitochondria.
Supplementing for Mitochondrial Health
Clean living, exercising, and healthy eating are the foundations for mitochondrial health, but dietary supplements can provide additional support. In particular, consider recommending supplements that are cofactors for mitochondrial function, provide antioxidant support, and support mitochondrial biogenesis.
Coenzyme Q10 (CoQ10) often tops the list of nutritional supplements for mitochondrial function because it supports antioxidant status as well as energy production. CoQ10 is a necessary cofactor in the electron transport chain and is concentrated in the cells with the greatest mitochondrial density. And CooQ10 has been shown in placebo-controlled trials to support antioxidant enzyme systems.
Several other nutrients have also been shown to support healthy mitochondrial function in clinical or preclinical trials.
Vitamin D supports oxidative phosphorylation and modulates the production of reactive oxygen species during cellular respiration.
Magnesium is an enzymatic cofactor, and its concentration within mitochondria regulates ATP synthesis.
Acetyl-l-carnitine is a component of the inner mitochondrial membrane and supports oxidation of fatty acids.
Alpha-lipoic acid (ALA) supports antioxidant systems as well as mitochondrial biogenesis.
Pyrroloquinoline quinone (PQQ) is also emerging on the scene of mitochondrial-supportive nutrients. Similar to CoQ10, PQQ participates in energy transfer within the mitochondria and supports antioxidant defense systems. Researchers at the University of California-Davis published a study in 2014 in the Journal of Biological Chemistry that demonstrated PQQ’s essential role in activating genes that support mitochondrial biogenesis. PQQ is present in many foods, but has not been found to be synthesized in the human body.
Thriving with Mitochondrial Health
Supporting mitochondrial function is a foundational approach to nurturing health in cancer survivors. Promoting mitochondrial health can not only help your patients increase their energy and endurance, but also maintain healthy cognition and nervous-system function. Other benefits of mitochondrial health include cardiovascular wellness and normal detoxification. Cancer survivors who focus on diet, dietary supplements, exercise, and other lifestyle patterns that support their mitochondria and other subcellular machinery will experience a happier and healthier quality of life, and practitioners can feel good about supporting them on their journey.