April 12, 2011
Here’s an interesting study which showed that drinking more than recommended amounts of alcohol can significantly increase your risk of certain types of cancer. Eight European countries enrolled over 250,000 people prospectively over 13 years and found that drinking too much alcohol could account for nearly 45 of cancers of the mouth, voice box and throat in men and 25% of those cancers in women. The rates for liver cancer were 33% and 18%, respectively for men and women. The researchers don’t have a good explanation for why alcohol can increase your chances of cancer. One proposed mechanism is the possibility that alcohol somehow damages DNA, preventing cells from repairing itself.
I’ve written in the past about how chronic reflux in the throat due to untreated obstructive sleep apnea can lead to an increased risk for pre-cancerous changes in the throat, as well as increasing inflammation in the nose and lungs. Chronic low-grade irritation and inflammation is a known risk factor for malignant degeneration. Other studies have shown that obesity is also an independent risk factor for cancer, particularly with breast and prostate cancers. It’s a given that if you’re overweight, you’ll have a higher chance of having obstructive sleep apnea. Multiple breathing pauses while sleeping can cause vacuum forces that literally suction up your stomach juices into your throat. Stomach juices not only include acid, but also bile, digestive enzymes, and even bacteria.
Not sleeping effectively due to breathing pauses can prevent adequate blood supply to the reproductive and digestive organs, as well the the peripheral organs such as the skin. Chronic hypoxia is a known aggravator of oxidative stress, which is one of the proposed mechanisms cancer generation. Chronic hypoxia and chronic inflammation are double whammies in cancer research.
I realize that this is not your typical, genetics-molecular biology explanation for cancer development, but if you look at it from a broader perspective, it does have some merit which deserves further investigation. Maybe cancer researchers should place sleep apnea as an additional risk factor for cancer.
What do you think about my hypothesis?
March 3, 2011
Colon cancer is usually thought to be due to hereditary causes, along with your diet and lifestyle factors, but a new study revealed that sleeping less than 6 hours per night increases your chances of getting colon cancer by 50%, compared with sleeping 7 hours per night. The study authors speculate that perhaps melatonin may be involved, but no plausible explanation was given.
Here’s my take on it: Lack of sleep of poor quality sleep causes a physiologic state of stress. Your adrenaline levels are constantly increased. Since digestion is your last priority (especially when you’re running from a tiger), blood flow and nervous system activity are shut down when you’re under stress. Now imagine if you place food in your bowel, and your gut is not able to digest properly, or clear toxins appropriately. Hypoxia (low oxygen) causes local tissue damage (causing inflammation) and what’s called neo-vascularization, where new blood vessels are created to try to bring in more nutrients. Chronic over-stimulation of tissues in a state of low oxygen levels can create a perfect storm for cancer development. This process can also be applied to reproductive organs such as breast or prostate.
If you have or had colon cancer, how many hours of sleep do you normally get?
December 29, 2010
I just happened to come across a study that showed that hysterectomy is associated with a higher risk of developing renal cell carcinoma. Furthermore, undergoing a hysterectomy at an earlier age increases your chances of renal cell carcinoma even more. There was also a small, but significant increase in the rate of bladder cancer. At first glance, this may have nothing to do with obstructive sleep apnea, but once I began to dig a bit deeper into the research literature, here’s how I connected the dots between hysterectomy and renal cell carcinoma:
1. Hysterectomy generally produces surgical menopause. The study didn’t mention what percentage of women also had their ovaries removed, but I’m willing to bet it’s a significant number. Menopause by definition causes sleep disturbances due to a drop in estrogen and progesterone. Progesterone acts as an upper airway muscle dilator, which helps to tense the tongue. Diminishing progesterone allows your tongue to become more relaxed, allowing more frequent obstructions and arousals. This causes less efficient sleep, leading to slow weight gain.
2. Weight gain narrows the throat even further, aggravating or uncovering obstructive sleep apnea. Poor quality sleep also produces vasomotor (or neurologic) symptoms such as night sweats, hot flashes, insomnia, irritability and mood swings.
3. Chronic hypoxia and physiologic stress on the body shunts blood and nervous innervation away from unnecessary body parts and organs when under stress, such as your digestive system, reproductive organs, skin, and your genitourinary system (which also includes your kidneys).
4. Obesity has been shown to be linked to increased risk certain cancers, including the colon, esophagus, prostate, kidney, gallbladder and in women cancer of the breast and reproductive organs. Notice that these are all digestive or genitourinary organs (expect for esophageal cancer, which is mostly due to reflux from apneas).
5. Here are the most common risk factors for renal cell carcinoma: age 50 to 70, obesity, smoking, and hypertension. Notice how all these are risk factors for obstructive sleep apnea as well. We know that nicotine can relax the lower esophageal sphincter, which aggravates more reflux into the throat.
Early menopause has also been shown to increase your risk of heart disease as well. Since we know that untreated obstructive sleep apnea is a major risk factor for heart disease, all these these findings are not surprising.
What do you think about the connections that I’ve made? Please enter your comments in the text area below.
December 14, 2009
I’ve been accused in the past of of trying to link everything to sleep apnea. While not everything is caused by sleep apnea (taxes, the weather, etc.), I can make a good argument that not breathing properly during the day and while sleeping can directly or indirectly affect every aspect of our state of health and well-being. Obstructive sleep apnea is only a small fraction of what I describe in my sleep-breathing continuum. Due to the way we define sleep apnea, you can have major sleep-breathing problems and not have any sleep apnea.
Along these lines, here’s something interesting to think about: Can a sleep-breathing problem cause or aggravate breast cancer?
Drinking alcohol was found to increase a woman’s risk of not only developing breast cancer, but also increase the risk of developing recurrence in breast cancer survivors. In a recent study from Kaiser Permanente, women who drank 3-4 glasses of wine per week were 34% more likely to develop a recurrence compared with women who drank little to no alcohol.
The researchers speculated that alcohol can increase levels of estrogen, which increases metabolism. However, they didn’t have a clear explanation for these findings. What’s more relevant to this discussion is the fact that post-menopausal women and overweight women who drank were at higher risk for recurrence.
Like many other studies, researchers never commit themselves to state that one thing causes another—they can only state statistical likelihood of an association, but not causation.
Similar finding are being reported with prostate cancer—that heavy alcohol consumption and being overweight increases your risk of recurrence.
Here’s my interpretation of these findings: Alcohol is a strong muscle relaxant that’s usually taken with dinner or later in the evening. Muscle relaxation during deep sleep causes more frequent obstructions in your breathing, which can cause or aggravate existing sleep apnea. The resulting activation of the sympathetic nervous system leads to a relative hypoxic environment in preferential body parts and organs, such as the gastrointestinal system, the reproductive system, the skin, and the hands and feet.
Since the breast is a combination skin and reproductive structure, it’s more susceptible to various levels of hypoxia. Physiologic stress that develops in sleep apnea constricts blood vessels that feed blood into the breasts. This is also why many women with breast cancer also have cold hands and feet.
As I’ve described in my book, Sleep, Interrupted, hypoxia creates chemical mediators that tell the body to send more blood. One particular substance is vascular endothelial growth factor, or VGEF, which promotes new vessel formation and more aggressive tissue growth and regeneration.
Menopause is stage in life in a woman’s life where progesterone slowly diminishes, leading to more and more frequent obstructions and arousals (since progesterone promote tongue muscle tone). Furthermore, inefficient sleep can promote weight gain. Weight gain narrows the throat, leading to more frequent obstructions. Women’s rate of cardiovascular disease also increases significantly after menopause, along with a significant increase in obstructive sleep apnea. We know that sleep apnea can cause heart disease, but so far, these conditions are treated separately. It’s not surprising that breast cancer is treated independently, rather than looking at the bigger picture.
Granted, this is an unorthodox explanation for breast cancer, but as Einstein once said, "The significant problems we face cannot be solved at the same level of thinking we were at when we we created them." In other words, we must think outside the box.
What I’m proposing doesn’t contradict traditional explanations for breast cancer. Rather, it’s a different perspective that can only complement existing treatment options.
What you do think about this explanation? Please enter your responses in the box below.
November 23, 2009
There’s been a lot of press coverage recently about the new mammography screening recommendations for breast cancer. The United States Preventive Service Task Force recently recommended that women begin routine mammography screening at age 50, rather than 40. This is an important issue for me as my aunt died from metastatic breast cancer in her early 40s.
One thing that I see over and over again is how obstructive sleep apnea can affect every aspect of your health, from your mood, to diabetes, to heart disease. You may think that cancer and sleep apnea are totally separate conditions, but with the human body, everything is ultimately connected in one way or another. This lead me ask the question: Do sleep apnea and cancer have a common origin?
In my practice, anytime I see a patient with a history of breast cancer, I almost consistently see the following: cold hands or feet, unrefreshing sleep, an inability to sleep on their backs, and a severely snoring parent, typically with cardiovascular disease. What’s remarkable is that when I examine their airways with a fiberoptic camera, the space behind the tongue is usually very narrow, especially when they lie flat on their backs. This anatomy leads to repeated obstructions and arousals, especially when sleeping on their backs and in deep sleep, when muscles relax the most. For this reason, these women prefer not to sleep on their backs.
In my book, Sleep, Interrupted, I describe a process where due to poor breathing and inefficient sleep, a physiologic stress state is created, which leads to lack of proper blood flow to certain parts of the body that are considered unimportant when you’re in a fight or running from a tiger. These areas include the digestive system, reproductive organs, your hands and feet, and your skin, amongst others.
During periods of stress (whether internal/physiologic or external/emotional), there can be severe blood flow restriction to any of these body areas. As an example of how dramatic this can be, there’s a description of a man who was severely injured during battle, and most of his abdominal wall was missing, with his bowels clearly visible. While he was recovering in bed, his doctors noticed that whenever he was angry or in pain, his bowels were dark and dusky, whereas when he was happy, his bowels looked pink and healthy. Similarly, there can be dramatic fluctuations in blood flow to the breasts depending on the woman’s mood and stress-inducing states.
One common finding in both cancer and sleep apnea research fields is that hypoxia (lack or oxygen) in tissues can lead to production of signals that tell the body to bring in more blood and nutrients. As a result, a number of inflammatory mediators are released, including the well-known vascular endothelial growth factor (VEGF). VEGF promotes local growth of blood vessels in oxygen-poor areas. Imagine if this process happened all the time, with slow but gradual growth of local tissues, with activation of genes and proteins that promote more inflammation and more cell reproduction.
We know that chronic overstimulation of any tissue can lead to cell replication that can go out of control. Chronic overstimulation of breast tissue can initially lead to localized benign growths or cysts, and some of these can end up transforming into malignancies. Perhaps some women with certain genes may be more susceptible to this transformation. This same process can also be described for prostate cancer.
Most younger breast cancer survivors probably won’t have obstructive sleep apnea if tested. But what they most likely will have is upper airway resistance syndrome, which results in multiple microscopic obstructions and arousals that prevents deep, efficient sleep. This can cause the nervous system to become hypersensitive, with increased physiologic states of stress. As they gain weight later on in life, many will progress into formal sleep apnea.
Studies show that breast cancer survival is poorer in obese patients. Similar findings are also found with prostate cancer. This is possibly explained by the fact that the more obese you are, the more likely you’ll have obstructive sleep apnea. Having obstructive sleep apnea significantly increases your risk of dying in general.
Granted, what I’m describing here is a very different perspective in explaining breast cancer, and is sure to be controversial in some people’s minds. However, rather than trying to explain breast cancer from a molecular, genetic, or organ level, wouldn’t you agree that it’s much more satisfying when you can explain this illness from a whole-person perspective? As much as Western medicine tries to deny it by fragmenting care to different specialties, we know intuitively that whether it’s the breast, the heart, the mind or the prostate gland, everything is ultimately connected.
What’s your opinion on this important issue? Please enter your comments in the box below.