4 min read- Insomnia and dementia have a complicated, two-way relationship.
- A new study finds half a million people in the US have insomnia-related dementia. This translates to 1 in 8 dementia cases.
- Insomnia is considered a “modifiable risk factor.” Doctors say that addressing sleep issues now could reduce the likelihood of future dementia.
Even your tracker warns you that a less-than-great night of sleep can have an effect on your brainpower. Now, a study published in the Journals of Gerontology: Series A not only clarifies that there’s a strong connection between people with insomnia and dementia. It reveals how much scientists underestimated the impact of skipping a few hours of rest. Lack of sleep led to significantly more cases of the debilitating disease than the researchers previously thought.
The good news is that most sleep problems are fixable. In other words, optimizing your sleep schedule or seeking a specialist for help may help lower your risk of dementia decades from now.
How Much Does Poor Sleep Impact Dementia Cases?
NEARLY 1 IN 8 dementia cases were associated with insomnia. To put it into context, that’s half a million people in the US with insomnia. (An estimated 25 million Americans have trouble falling asleep or staying asleep, even when allowing enough time in bed to sleep).
“We were pretty surprised at the magnitude of the effect,” Yuqian Lin, a data analyst at Massachusetts General Hospital in Boston and lead study author, told Science News.
The researchers came to this number after analyzing information from the 2022 National Health and Aging Trends Study (NHATS). A total of 5,899 adults age 65 and up reported their sleep problems. This included how often they have trouble falling asleep, if they had issues staying asleep through the night, or both. They used this information along with cognitive test results to assess who had what they consider to be probable dementia. This meant people had a high likelihood of symptoms that could imply dementia. Afterward, the team calculated how many of these dementia cases could have been prevented if their sleep problems had improved.
After crunching the data, the researchers found that 12.5 percent were insomnia-related dementia cases. The number of dementia cases were tied to people in the 65-69 age group for women and the 70-74 age group in men.
The Complicated Relationship Between Insomnia and Dementia
INSOMNIA IS CONSIDERED a “modifiable risk factor.” It means that early intervention—in this case, tackling the root behind a person’s sleep issues—could reduce the chance of developing future dementia. According to the study, insomnia may have more of an impact than other modifiable risk factors for dementia such as hearing loss and high blood pressure.
That said, insomnia and dementia have a complex, bidirectional relationship. In other words, each condition influences the other.
“Healthy sleep is a necessary foundation for cognitive health because it is crucial for memory consolidation, decision-making, emotion regulation, ‘brain cleaning’ through the glymphatic system that flushes out toxins from the brain during deep sleep... all important aspects of maintaining brain health over time,” explains Jade Wu, PhD, a behavioral sleep medicine specialist and author of Hello Sleep: The Science and Art of Overcoming Insomnia Without Medications.
Dr. Wu goes on to say that insomnia can cause a vicious cycle where people are in a bad mood with low energy during the day. As a result, people are more likely to stay sedentary and isolate themselves—a well-known contributor to dementia risk.
The other side of the conversation is how dementia can worsen insomnia symptoms. People with dementia (even at an early-stage) show changes in sleep patterns from excessive daytime napping to trouble staying asleep.
Some theories are that the neurological condition damages brain areas involved in the sleep-wake cycle or lower the amount of time spent in deep sleep, which may explain people with dementia who wake up multiple times in the night. Dementia may also be messing with brain chemicals. One example is melatonin. The hormone rises when the sun goes down to make people sleepy. However, research shows people with dementia tend to have lower levels of melatonin in the evening.
Tackling The Most Common Cause of Insomnia
INSOMNIA IS A complicated condition, and everyone’s situation is a little different. With that said, there are some blanket recommendations for anyone who finds themselves tossing and turning in the middle of the night.
The most common cause of insomnia is stress. When your mind is racing before bed, you’re not in an ideal situation for sleep.
Stress raises your cortisol and adrenaline levels, keeping your body in an alert state. Over time, stress and a continued lack of sleep can leave your body exhausted. That itself can cause more stress on the body.
Christopher Winter, MD, a sleep medicine specialist, neurologist, and author of The Sleep Solution: Why Your Sleep Is Broken and How to Fix It, first recommends learning the ins and outs of insomnia. Most importantly, he finds people are most empowered when they know something can be done.
“It's tempting to pour all your efforts into falling or returning to sleep, but this kind of pressure just makes insomnia worse,” adds Dr. Wu. Instead, she also advocates for finding the root cause for your insomnia. For example, people who are stressed may find it helpful to wind down with caffeine-free tea with calming ingredients such as lavender or chamomile. She adds that exercising earlier in the day can release endorphins and lower cortisol levels.
“Get outdoors for daytime light exposure, move your body, socialize, engage in mentally stimulating and meaningful activities, get involved in community, and listen to your body's natural sleepy cues,” Dr. Wu says.
While there are melatonin and other supplements meant to promote sleep, Dr. Winter warns against sedating yourself with pills. If you experience chronic insomnia, Dr. Winter advises seeking help from sleep specialists.
Jocelyn Solis-Moreira, MS is the associate health & fitness for Men's Health and has previously written for CNN, Scientific American, Popular Science, and National Geographic before joining the brand. When she's not working, she's doing circus arts or working towards the perfect pull-up.
