Obesity is associated with a host of health problems. Best known of these are probably heart disease, stroke, type 2 diabetes and certain types of cancer.
But the heavier we become, the more likely we are to develop another serious health problem: obstructive sleep apnea. This sleep disorder occurs when tissue in the back of your throat narrows or blocks your airways, causing you to briefly stop breathing. The pauses, which typically last for a few seconds, can occur up to 30 times a minute. Although they may not wake you up, they can keep you from entering deep, restful sleep.
Not everyone with sleep apnea is overweight, but our throat tissue thickens along with other body tissue when we put on extra pounds, thus raising the risk for developing the condition. Other risk factors include being male, being older, smoking, as well as various anatomical problems.
At least 12 million Americans have sleep apnea, but most are undiagnosed and untreated, according to the National Heart, Lung, and Blood Institute.
The influence of fast food
On Monday, Salon ran an interesting excerpt from Reuters reporter David K. Randall’s new book, “Dreamland: Adventures in the Strange Science of Sleep.” In the excerpt Randall notes how “the spread of Western fast-food companies like McDonald’s, Kentucky Fried Chicken, and Pizza Hut to emerging countries such as China and India may be the greatest growth engine” for companies that make medical devices to treat sleep apnea.
“Simply put,” writes Randall, “more fat in the bodies of the world’s population equals a larger number of sleep apnea cases.”
Here’s how the CEO of one of these medical-device companies described the situation to Randall: “Genetically you’re still engineered for a low-calorie, low-fat diet. That’s what your body has been optimized for over [the] centuries. Boom, you introduce burgers, and your body is not going to handle it. One of the outcomes is going to be a skyrocketing in the prevalence of sleep-disordered breathing.”
Impact on the mind
That may be good news for the CEO’s company, but not for the rest of us — and not just because of the physical health risks associated with sleep apnea, which include high blood pressure, kidney disease and vision problems. As Randall also points out in his excerpt, untreated sleep apnea imposes a significant mental toll on individuals as well:
As scientists began to understand sleep apnea in more depth, they started to see it as the foundation for serious illnesses affecting the mind. In one study, researchers at UCLA conducted brain scans of patients with long histories of sleep apnea and compared them with the scans of control subjects who had normal sleep patterns. The investigations focused their inquiry on the mammillary bodies, two structures on the underside of the brain so named because they resemble small breasts. Mammillary bodies are thought to be an important part of the memory and have long been associated with cases of amnesia. This memory center of the brain was 20 percent smaller in patients with sleep apnea. Had a doctor looked at a patient’s brain scan alone, it would have suggested severe cognitive impairment: A similar shrinkage in the size of the mammillary bodies is found in patients with Alzheimer’s disease or those who experienced memory loss as a result of alcoholism. It was the first indication that sleep apnea leaves a permanent scar beyond the daily difficulties of focus and attention that come with sleepiness.
A study published in the Journal of the American Medical Association supported this conclusion. Kristine Yaffe, a professor of psychiatry at the University of California-San Francisco, led a study that recruited nearly 300 elderly women who were mentally and physically fit. The average age of the subjects in the study was 82. Each woman spent a night in a sleep lab, and Yaffe found that about 1 in every 3 met the standard for sleep apnea. Yaffe re-examined each woman five years later. The effects of age on the mind seemed to depend on the quality of sleep. Nearly half of the women with sleep apnea showed signs of mild cognitive impairment or dementia, compared with only a third of the women who slept normally. After controlling for factors such as age, race, and the use of medicines, Yaffe found that the women with sleep apnea were 85 percent more likely to show the first signs of memory loss. The frequent interruptions in sleep and the reduced oxygen in the brain may reduce the brain’s ability to form and protect long-term memories.
You can read the excerpt from Randall’s book on the Slate website. It includes the story of how, in 1980, a resourceful Australian physician made the first sleep apnea treatment device out of a diving mask, a vacuum cleaner and some plastic tubes.