Can Skimping on Sleep in Middle Age Lead to Trouble Later in Life?

Have you been skimping on sleep? Some people have more to do in a single day than they can accomplish in the hours they have. As a result, they steal time from the hours they should be sleeping. Young people may be able to burn the candle at both ends occasionally without immediate consequences. However, one study suggests that middle-aged people who do this consistently are at elevated risk for dementia decades later (Nature Communications, April 20, 2021). Another shows that missing just an hour and a half of sleep a night can disrupt appetite and metabolism and lead to weight gain.

How Sleeping Less Can Lead to Weight Gain

Most people know that severe sleep deprivation has an impact on next-day functioning. Not only do you feel dopey, you may also feel hungry and eat more than usual in an attempt to stay more alert. But what is the impact of skimping on sleep just a little, as so many Americans do? A recent study suggests that this habit could also lead to some overeating (Annals of Internal Medicine, July 7, 2026).

The investigators recruited 95 adults who usually sleep 7 to 8 hours. During part of the study, the volunteers maintained that pattern. In another part of the study, participants delayed their bedtimes by 90 minutes. Both parts of the study lasted six weeks, and the researchers monitored sleep and activity levels, body weight, waist circumference, body composition and hormones. During the short-sleep phase, people tended to be somewhat more sedentary and also ate more. Thus, it is hardly surprising that they gained about a pound, on average, during those six weeks. Over the long term, this could lead to weight gain and metabolic disruption.

Might it also contribute to cognitive decline? That was the subject of an earlier, long-term study.

What’s the Problem With Skimping on Sleep?

That research was based on a large study of British civil servants that began in the 1980s. Nearly 8,000 individuals answered questions about their habits and their health every four years or so. Although they were self-reporting how much they slept, the scientists confirmed those reports with a subset of people who wore accelerometers to track their hours asleep. These largely confirmed the participants’ reports.

People Sleeping Less Than Six Hours Nightly

Compared to people who reported sleeping seven hours a night, those who get less than six hours of sleep a night in their 50s were 22 percent more likely to develop dementia by the time they were in their 80s. The investigators made numerous adjustments for other factors. These included mental health, smoking, alcohol consumption, body mass index and conditions like hypertension or diabetes. Any of those might potentially increase a person’s risk for dementia, but the relative risk held up even after the calculations. This observational study can’t establish cause and effect, so the authors conclude: “short sleep duration in midlife is associated with an increased risk of dementia.”

It was important to look at healthy people skimping on sleep while they were still free of dementia. Previous studies have linked sleep disturbances in later life with a greater likelihood of dementia. But there was no way to know if the cognitive dysfunction contributed to the sleep problems or vice versa. While we still can’t say that staying up late will cause dementia, the evidence suggests that the association starts even before a person has dementia.

Learn More:

You can learn more about protecting yourself from dementia with our podcast. Show 1214: How to Defend Your Brain During the Pandemic and Beyond and Show 1092: How Can You Overcome Alzheimer Disease? are both interviews with Dr. Dale Bredesen. If you’d like to listen to advice on better sleep, you might consider Show 1246: Getting the Sleep You Need Even in Anxious Times. If you can manage to avoid skimping on sleep, you may be able to keep your brain sharp longer. You might also want to listen to Show 1393: How to Get the Sleep You Need with Dr. Roger Seheult. Dr. Seheult also discusses the interactions between sleep and diet in Show 1480: The Sleep Reset.