Before I present this post I want to add a few disclaimers.

First, there are a lot of unique considerations for individuals, including which sleeping positions are uncomfortable, impair breathing, complicate sleep apnea treatment, etc. A good article I read while preparing this post states: “Sleep habits are highly personal, and the same goes for your ideal sleep position. A side sleeping position has many advantages and fewer drawbacks than a stomach or back position. Ultimately, the position that helps you fall asleep, stay asleep, and get quality rest is the best one for you.”

Second, the science of how our brains wash out the accumulated junk of a full day’s cognitive work while we are sleeping is still very much being studied. There is fascinating stuff to learn, including the magic of the brain’s glymphatic system and washing cycle mode. As a primary care doctor I am not contributing to this research by any means. But I do have a vested interest in helping to prevent or slow neurodegenerative diseases like the ones I see every day (dementia, Parkinson’s, general cognitive decline, etc.)

The typical articles we read about preferred sleep positions concentrate mostly on our physical comfort, breathing, and associated medical issues. So I’m going to quickly summarize that and let the interested reader click through to more information if desired. But then I’m going to spend the bulk of this post examining an overlooked consideration - which sleeping position best clears out the brain of leftover metabolites and junk that can accumulate and lead to long term problems?

In short, side sleeping is generally considered the most beneficial position, offering advantages for spine alignment, reducing snoring and sleep apnea symptoms, and aiding digestion for most people. Everyone is different, and so following your body signals here goes a long way. For example, side sleeping may cause shoulder and hip pain, especially in older people. Forcing it will result in bad sleep. But one of the best tricks I learned along the way in this regard is to put a pillow between my knees while side sleeping. For me, this keeps my spine, hips, and knees in alignment and therefore happier in the morning. Some nuances between side, back, and front sleeping are discussed further in this article from The National Council on Aging (NCOA) as promised. And a bonus article from Houston Methodist on sleep positions.