7 min|Dr. Maya Kuczma
Mitochondria (Part 4): What Causes Mitochondrial DeclineEducation
First, the bad news: there is a natural decline in mitochondrial function that occurs as we age
This decline is thought to be one of the reasons why we age. It is the reason we blame certain symptoms on aging.
You’re tired? You must be getting old. You’re having trouble concentrating, or remembering names? That’s par for the course, as we get older. You’re gaining weight? It happens over time. But what if... it didn’t? What if many of the symptoms we attribute to aging are signs that our mitochondria are breaking down too quickly?
Our understanding of the role mitochondria play in aging and the development of disease processes indicates that mitochondrial decline may be at the root of many common symptoms such as fatigue, pain, cognitive decline, and weight gain. And while we expect the mitochondria to decline slowly as we age, many factors in our life can speed up the process, causing us to feel sick and tired, before our time has come.
We are what we eat, and our mitochondria are no different. They require many different nutrients in order to make energy. If we are not fueling them correctly, they begin to dysfunction. A highly processed diet that is nutrient poor, and lacking antioxidants, vitamins, and minerals, does not provide the building blocks the mitochondria require to function optimally. Additionally, taking in certain foods directly damages mitochondria:
- Sugar leads to spikes in insulin levels, triggering a release of inflammatory chemicals known as cytokines that directly contribute to oxidative stress, inflammation, and damage to the mitochondria(1)
- Vegetable oils high in omega-6 polyunsaturated fatty acids, such as soybean oil, corn oil, sunflower oil, can lead to oxidative damage of mitochondrial DNA(2)
- Monosodium glutamate (MSG) decrease antioxidant enzymatic activity within mitochondria(3)
2. Toxin Exposure
We are living in a very toxic world. Within a single day, we are exposed to multiple toxins via the water we drink, the food we eat, the air we breathe, and the products we put on our skin, teeth, and hair. Exposure to toxins leads to the development of reactive oxygen species (ROS), also known as free radicals. Mitochondria appear to be particularly sensitive to the damaging effects of free radicals.(4) While our understanding of mitochondrial toxicity is still developing(5), we have identified the deleterious effects of many toxins, for example:
- Alcohol consumption creates oxidative stress that directly damages mitochondrial DNA; consistent consumption, as well as increasing age, decreases our ability to repair ethanol-induced mitochondrial damage(6)
- Glyphosate, when utilized within the herbicide RoundUp, negatively impacts the energy-producing pathways within mitochondria(7); alters mitochondrial activity within sperm leading to a reduction in sperm motility(8); and increases reactive oxygen species (ROS) that lead to oxidative damage(9). Additionally, glyphosate binds to manganese within plants, disrupting our ability to absorb it; our mitochondria require manganese for a variety of processes(10)
- Methyl-mercury decreases ATP production and induces oxidative damage to mitochondrial DNA(11)
T3, a hormone produced by the thyroid, is a major regulator of mitochondrial activity. T3 stimulates ATP production as well as mitochondrial biogenesis.(12) If we have an underactive thyroid, that cannot release healthy amounts of T3, or we have trouble converting T4 (another thyroid-produced hormone) into T3, our mitochondria.
When we eat carbohydrates, they are broken down into glucose and our blood sugar increases; in response, our body releases insulin to drive the glucose into our cells. If we consistently eat an excess of carbohydrates, our blood sugar is consistently high, and our body has to release more and more insulin in response. Chronic fluctuations in insulin lead to a release of the stress hormone cortisol, which inhibits fat metabolism.
In response, the mitochondria burn sugar, rather than fat, to create ATP. Sugar is a less efficient source of energy. The body will require more and more sugar to produce energy, causing our blood sugar to swing, cravings to increase, and fat metabolism to decrease. This creates another vicious hormonal cycle of weight gain, fatigue, and cravings that can feel impossible to resist.
Remember back in high-school biology, how the mitochondria is the ‘powerhouse of the cell’? And that it gets its name by converting what we eat into energy, through a complex process that uses a lot of hydrogen? (if not, head back to Part I for a review) Where do we get all of this hydrogen? From a compound rich in hydrogen – water (H2O). Without water, we can’t make ATP. Even mild dehydration decreases the amount of available hydrogen for ATP production. Furthermore, ATP production is required to generate a gradient that helps to pull water into the cell. Simply drinking more water will not necessarily ensure that the cells become hydrated; we require the gradient produced by healthy mitochondrial activity to draw the water into the cells (13).
5. Viral Infections
Viruses are always looking for hosts to live within. The mitochondria makes sense as the best region to ‘hijack’ - take control of the mitochondria and you have reign over many cellular functions, and with that, take control of the cell itself. We must admire viruses’ tenacity - they evolve at a rapid rate and have forged intricate methods to ensure their survival within us, such as this ability to take over our mitochondria. Many viruses have been shown to damage mitochondrial DNA in an effort to control the entire cell.(14) Certain viruses, such as the Epstein-Barr virus, induce mitochondrial dysfunction that increases our risk for several cancers.(15) Herpes simplex type 1 (HSV1) has been linked to imbalances in the calcium homeostasis of host cells, leading to mitochondrial dysfunction within neurons.(16)
Many viruses remain in our body forever, and can cycle through periods of flaring and settling leading to chronically harmful effects on the mitochondria. Our understanding of how viruses may trigger long-term mitochondrial damage is in its infancy, but beginning to deepen, particularly within studies of myalgic encephalomyelitis (also known as chronic fatigue syndrome), and autoimmune conditions such as multiple sclerosis. (17,18)
Stress can interfere with mitochondrial function via elevated cortisol levels. Cortisol, especially when chronically elevated, leads to poor fat metabolism, increased demand for sugar, and a decreased ability to fight off viruses - all of which are factors that we now know negatively impact our mitochondria. Stress can also indirectly affect mitochondria by leading to detrimental dietary and lifestyle choices - a perception of high levels of stress may cause us to eat a nutrient-poor, glucose and toxin-laden diet. We may under hydrate when we’re busy, and we may not get the rest we need to fight off a virus.
All of this information can feel disheartening. Most of us are not exposed to only one of these threats to our mitochondria; we may encounter all of them within any given day. These threats compound, leading to chronic inflammation, dysregulated blood sugar, and underperforming mitochondria, all of which leads to further stress, physically and emotionally.
It can seem like a cycle that we cannot get out of, particularly if the treatments we are offered do not take into account the delicate nature of our cellular health. So how do we break free? How can we help our-cell-ves? Join us for Part 5 and Part 6 where we will dive into the steps you can take to improve the health of your mitochondria.