If you don't get enough sleep -- or quality sleep -- that means you may be like the roughly 50 million to 70 million Americans who suffer from chronic sleep disorders that decrease daily functioning and adversely affect health and longevity. (In fact, one study found that not getting enough sleep carries a greater mortality risk than smoking, high blood pressure, and heart disease.)

And now there's another reason to focus on improving your sleeping habits: According to new research, chronic sleep problems may be linked to Alzheimer's.

Why? Poor sleep is linked to greater levels of amyloid protein build-up in the brain, and amyloid plaque levels are linked to Alzheimer's. (Unfortunately, it's difficult to detect plaque build-up until an autopsy is performed -- which is, of course, too late.)

As Dr. Erik Musiek, one of the authors of the study, says, "It wasn't that the people in the study were all sleep-deprived. But their sleep tended to be fragmented. Sleeping for eight hours at night is very different from getting eight hours of sleep in one-hour increments during daytime naps."

For example, after two months mice with disrupted circadian rhythms (one assumes the researchers kept waking the mice up at odd intervals, which seems pretty mean) developed considerably more amyloid plaque than mice who were left to enjoy normal sleep cycles.

The same thing happens with people. Researchers studied older adults and found that "people with preclinical Alzheimer's disease had more fragmentation in their circadian activity patterns, with more periods of inactivity or sleep during the day and more periods of activity at night."

Which, in non-researcher language, means sleep problems were associated with early stages of Alzheimer's.

Granted, the relationship between sleep and Alzheimer's may be correlated, not causal. Poor sleeping habits may help cause Alzheimer's, or it may be a symptom that appears in the early stages of the disease. 

"At the very least," says Dr. Yo-El Ju, another author of the study, "These disruptions in circadian rhythms may serve as a bio-marker for preclinical disease."

That's yet another reason to focus on getting enough good sleep. (If you're struggling, here are some surprising ways to sleep a lot better.)

Not only will getting more sleep improve your memory, your performance, and your mood... it may also help you avoid Alzheimer's.

Sounds like reason enough to me to start changing your sleep habits.