Deep sleep may reduce memory loss in Alzheimer’s disease

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A new study from the University of California, Berkeley, reveals that deep, non-REM slow-wave sleep can act as a protective factor against memory decline in older adults who already have high amounts of Alzheimer’s disease pathology.

Disrupted sleep has been associated with a faster accumulation of the protein beta-amyloid in the brain which is linked to memory loss caused by dementia.

But deep sleep can act as a “cognitive reserve factor” and increase resilience against beta-amyloid.

The research suggests that deep sleep can help protect against Alzheimer’s disease outcomes.

The Study

The research team recruited 62 older adults who were healthy and not diagnosed with dementia from the Berkeley Aging Cohort Study.

Researchers monitored the participants’ sleep waves with an EEG machine and used a PET scan to measure the amount of beta-amyloid deposits in their brains.

Half of the participants had high amounts of amyloid deposits, while the other half did not.

After they slept, the participants completed a memory task that involved matching names to faces.

Those with high amounts of beta-amyloid deposits in their brains who experienced higher levels of deep sleep performed better on the memory test than those with the same amount of deposits but who slept worse.

The researchers also controlled for other cognitive reserve factors, including education and physical activity, and still found that sleep demonstrated a marked benefit.

This suggests that deep sleep contributes to salvaging memory function in the face of brain pathology.


The study’s findings indicate the importance of non-REM slow-wave sleep in counteracting some of the memory-impairing effects of beta-amyloid deposits.

According to Matthew Walker, a senior author of the study, “It now seems that deep NREM sleep may be a new, missing piece in the explanatory puzzle of cognitive reserve.

This is especially exciting because we can do something about it. There are ways we can improve sleep, even in older adults.”

Experts suggest that sticking to a regular sleep schedule, staying mentally and physically active during the day, creating a cool and dark sleep environment, minimizing coffee intake late in the day, and reducing screen time before bed are some ways to improve sleep quality.

While the study’s sample size was small and the research is still in the early stages, these findings could lead to more extensive experiments examining sleep-enhancement treatments that could have far-reaching implications.

How to prevent memory loss

Memory loss can be a natural part of the aging process, but there are steps you can take to help prevent it. Here are some tips:

Exercise regularly: Exercise has been shown to help maintain cognitive function and memory. Aim for at least 30 minutes of moderate-intensity exercise most days of the week.

Eat a healthy diet: A diet rich in fruits, vegetables, whole grains, lean protein, and healthy fats can help keep your brain healthy.

Get enough sleep: Sleep plays a critical role in memory consolidation. Aim for 7-8 hours of sleep per night.

Stay mentally active: Engage in activities that challenge your brain, such as reading, doing puzzles, or learning a new skill.

Stay socially active: Social isolation has been linked to an increased risk of cognitive decline. Stay connected with friends and family.

Manage stress: Chronic stress can have negative effects on brain function. Find ways to manage stress, such as through meditation or exercise.

Limit alcohol consumption: Heavy alcohol consumption can damage the brain and impair memory function.

Quit smoking: Smoking has been linked to an increased risk of cognitive decline.

Manage underlying health conditions: Conditions such as high blood pressure, diabetes, and depression can increase the risk of memory loss. Work with your healthcare provider to manage these conditions effectively.

By adopting healthy habits and making lifestyle changes, you can help protect your memory and maintain cognitive function as you age.

If you care about Alzheimer’s disease, please read studies about the blood test that can predict dementia, Alzheimer’s 5 years early, and one year of this exercise training may reduce risk of Alzheimer’s disease.

For more information about Alzheimer’s, please see recent studies that Coconut oil may help improve cognitive function in Alzheimer’s, and results showing strawberries could help prevent Alzheimer’s disease.

The study was published in BMC Medicine.

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