What Is Mitochondrial Biogenesis?
Your body is an adaptive machine, constantly adjusting to the changing environment you put it through. If you decide to run a marathon, your body doesn’t just kick it up a notch; it changes its own biology to adapt to your new strenuous routine to better energize and support you.
These changes occur in your cells, particularly your mitochondria—tiny power generators that are responsible for churning out 90% of your body’s energy.
But mitochondrial biogenesis is the specific mechanism that your body uses to respond to these adaptive changes in your environment.
As you become more fit as a marathon runner, adding more miles to your daily jog, your body needs more energy to accommodate your new stimulus. Mitochondrial biogenesis is the process of creating new mitochondria in order to match your new energy needs.
How do mitochondria create energy?
The food you eat cannot be readily used as energy by your cells. First, your body needs to convert food into usable chemical energy called ATP (adenosine triphosphate).
Your mitochondria create ATP through a process called cellular respiration, a biological operation of combining oxygen (from the air we breathe) and food molecules in order to produce energy.
In the case of glucose (most of our food is broken down to glucose), simplified cellular respiration looks like the formula below:
Glucose + Oxygen = Carbon Dioxide, Water, and ATP.
Water and carbon dioxide are byproducts of the process. Water is reused by the body, expelled in our sweat, excrement, and urine while we breathe out carbon dioxide.
ATP, the true valuable outcome of the process, is used for energy. It fuels all the essential functions in our cells in order to keep us alive and well.
Structurally, ATP is a volatile compound just waiting to burst. But their design is intentional. Their portability allows energy to travel more freely. And their instability enables them to easily break apart, releasing their stored energy wherever they arrive.
How does mitochondrial biogenesis relate to aging?
Your mitochondria are always looking for ways to become more efficient because creating energy can be an expensive process. Maintaining an optimal number of mitochondria is key to a healthy cell. When your mitochondria are overburdened it can result in mitochondrial dysfunction, which can affect the way you age.
According to a review published in Current Aging Science, the mitochondrial free radical theory of aging (MFRTA) proposes that mitochondrial dysfunction results from free radicals, damaging byproducts that can wreak havoc in the cell.
Free radicals are a byproduct of cellular respiration. If your mitochondria count is too low and the energy demand is too high, your mitochondria will overwork themselves to generate the right amount of energy.
The more energy a mitochondrion produces, the more free radicals it produces as well.
Proposed as one of the nine hallmarks of aging, mitochondrial dysfunction only gets worse as you get older. Older mitochondria tend to change their shape inefficiently, and research from The Journals of Gerontology shows that our mitochondrial count naturally declines as we age.
Mitochondria have a free radical problem.
Although free radicals can be generated from other functions, a review published in the Journal of Signal Transduction shows that mitochondria are the primary culprits for free radical damage.
And the mitochondria receive the brunt of the harm. A review published in Cell postulates that our mitochondria’s proximity to the source of free radical production makes it more prone to dysfunction. The mitochondria are essentially creating what kills them, pumping out energy that, in turn, creates byproducts that damage its own mechanisms.
But without the mitochondria, all the vital functions in your body would shut down like an abandoned factory. All cellular operations require the mitochondria’s consistent energy to work and maintain themselves. Their central role in your cellular function is why the health of your mitochondria plays a vital part in maintaining a healthy aging lifestyle.
How does mitochondrial biogenesis work?
Your mitochondria are very unique organelles within the cell because they have their own DNA called mtDNA. Your cells use DNA as the blueprint to create new proteins in your cells.
Typically, other parts of the cell use DNA from your nucleus to “print” new proteins for its structure and maintenance. However, your mitochondria use both nuclear DNA and mitochondrial DNA to create new mitochondria.
But to understand how mitochondrial biogenesis works, it’s critical to envision mitochondria as a network of organelles rather than focusing on just one.
As a mitochondrial network, your mitochondria change shape and size to adjust to your ever-changing energy needs through two processes: mitochondrial fission and fusion.
1. Mitochondrial fission
Mitochondria aren’t made from scratch. Instead, they replicate, similar to the cell division seen in bacteria. When energy demand increases, your network of mitochondria communicate with each other to increase their mass. They get large and start creating several smaller mitochondria.
But as noted before, mtDNA only provides a portion of the puzzle. The nucleus is also needed to send the remaining pieces of the protein structure to make these new mitochondria complete. These smaller mitochondria are more efficient and nimbler, providing immediate energy to wherever parts of the cell they serve.
Mitochondrial fission can also be useful for regulatory control, removing damaged or dysfunctional mitochondria from the network. Mitochondria can segregate the problematic material and expel them through fission. This “clean-up” process is called mitophagy (a combination of the words mitochondria + autophagy).
2. Mitochondrial fusion
Mitochondrial fusion is the process of “beefing” up existing mitochondria. Your mitochondrial network can power up existing mitochondria by fusing with newly minted mitochondria created in fission.
As a result, the existing mitochondria become longer in shape and far more streamlined in generating energy.
How do you trigger mitochondrial biogenesis?
If activating mitochondrial biogenesis can help improve the way you age, helping support a healthy aging lifestyle, what are some ways you can trigger it?
The most obvious solution to triggering mitochondrial biogenesis is to expend more energy, and the most efficient way to do that is to exercise.
A review article published in Applied Physiology, Nutrition, and Metabolism observed mitochondrial biogenesis during the recovery period following exercise. The review emphasizes how leading an active lifestyle can trigger exercise-induced mitochondrial expansion.
However, this same pathway in muscle cells can become impaired with inactivity. Therefore, a sedentary lifestyle, in effect, reduces mitochondrial count due to the lack of energy demand. Low mitochondria numbers can put you in jeopardy during bouts of oxidative stress when engaging in harmful activities like drinking, losing sleep, or eating junk food.
2. Intermittent fasting
Intermittent fasting is the practice of abstaining from consuming any calories for an extended period. The most common length of time is a 16-hour fast, following by an 8-hour eating window.
Diets that involve some sort of caloric restriction not only have ties with weight loss interventions but have been shown to have healthy aging effects. Nature Reviews Cardiology references a study that shows a fasting-mimicking diet (FMD) can reduce risk factors of aging in humans.
More specifically, mitochondrial changes have been the subject of study when observing how fasting can promote healthy aging. Research published in PLOS One suggests that dietary interventions that involve caloric restriction can promote mitochondrial biogenesis. The introduction of the publication reads,
“Dietary interventions such as caloric restriction promote "healthy aging" by inducing modifications in SkM metabolism via the induction of mitochondrial biogenesis and improvement of oxidative metabolism.”
3. Nicotinamide riboside
Nicotinamide riboside (NR) and some NAD-boosting supplements have shown promising evidence in their ability to support mitochondrial function. Nicotinamide riboside is a novel form of vitamin B3 that effectively increases levels of NAD+, a vital coenzyme your mitochondria use to generate energy and maintain mitochondrial health.
Research published in EMBO Molecular Medicine showed NR promotes mitochondrial biogenesis in mice.
Empower your powerhouses.
Your mitochondria are the powerhouse of the cell, effectively generating energy for your body’s vital functions. They exist in nearly every cell, and their proper function is intrinsically tied to your overall health.
Although you can’t reverse Father Time, you do hold the ability to help preserve your health condition. With proper care, you can maintain your independence and continue to do the things you love throughout the later years of your life.
Highlighted as one of the nine hallmarks of aging, supporting your mitochondrial health is an essential step towards maintaining your resilience. By continuing to take actions that promote mitochondrial biogenesis, you are actively alerting your body that you still want and need energy.
The biggest thing you can do is to continue to move your body. But mentally, your biggest hurdle will always be to spark the motivation to do so.
Reminding and educating yourself on just how much your lifestyle choices can impact your cellular health might be the push you need to lead a healthier life. So, continue to dive into the science and remember that every healthy choice you make empowers your powerhouses.