How Sleep Apnea Could Cause Cancer
However, it’s not enough to show simply that sleep apnea and cancer seem to occur together. This could be a coincidence, or both conditions might be due to a third condition.
To argue that sleep apnea causes cancer, we have to understand the mechanisms that sleep apnea triggers that can increase cancer risk.
The two main direct effects of sleep apnea are interrupted sleep and regular reduction of oxygen saturation. These cause other changes in the body that increase cancer risk, such as:
- Increased DNA mutations
- DNA transcription errors
- Increase in highly reactive oxygen
- Oxidative stress
- Increased inflammation
- Immune system chaos
- Increased prevalence of vascular endothelial growth factors (VEGF)
- Activation of the sympathetic nervous system
We’ll explain some of these effects below to help you understand how they lead to increased cancer risk.
Cancer occurs when some cells in the body mutate. These cells stop trying to work together and become rogue cells that try to promote themselves at the expense of your health.
Mutations cause this change.
With sleep apnea, mutations become more common, and the body also has more difficulty accurately transcribing DNA when making new cells. This is, essentially, another source of mutations.
Oxygen Shortage and Oxidative Stress
When your breathing stops because of sleep apnea, your body experiences an oxygen shortage. Oxygen shortage creates a chemical imbalance that leads to the creation of what are known as reactive oxygen species. These are unstable and attack the cells of your body. This attack creates what is known as oxidative stress, which increases the risk that cancer cells will develop and grow.
You’ve probably heard that antioxidants are healthy. The reason that antioxidants are healthy is that they neutralize reactive oxygen species and prevent oxidative stress.
Immune System Overactivity
You’ve probably noticed the swelling around a cut on your hand. This is inflammation, and it’s a sign that your immune system is working. Local inflammation in response to a wound is normal and healthy.
However, when your body is faced with nonspecific stresses, the immune system can respond in unhealthy ways. This includes causing inflammation throughout the body. You might not notice swelling–the effects are happening at the cellular level, with hormones and signal proteins that can lead to DNA damage, mutations, and the creation of cancer cells.
Cancer is aggressive and demands disproportionate resources from the rest of the body. It needs new blood vessels in order to supply the outsized appetite of tumors. VEGF is a signal protein that encourages the growth of new blood vessels. It helps tumors grow faster.
Sympathetic Nervous System Activation
The sympathetic nervous system is what we often call the “involuntary nervous system.” It regulates things like breathing and heart rate. When you experience an apnea attack, it causes your sympathetic nervous system to activate in an irregular way.
These irregular activations stimulate the release of inflammatory signals and proteins like VEGF that then spur the growth of tumors.