In Part I of this series, we discussed how researchers have discovered a previously unknown system in the brain for clearing out waste. The normal system in the body for this is called the lymphatic system. This new system in the brain has been called the “glymphatic system” from the word “glial” which refers to the glial cells in the brain.

We learned that deep sleep is more effective in this cleansing mechanism. We reach deep sleep in a circular process that begins with Nonrapid Eye Movement (NREM) sleep and progresses to Rapid Eye Movement (REM) sleep. The deeper the sleep, the better.

Flora Zhao, writing in The Epoch Times, tells us Americans today are sleeping less than ever.In 2023, 42 percent of Americans perceived that they got enough sleep, according to Gallup’s December 2023 poll. One in five people sleep less than five hours a night—compared with just 3 percent in 1942.

Shorter sleep duration can also be attributed to people going to bed later. One study found that delaying bedtime by just one hour reduces total sleep by 14 to 33 minutes each night.

In addition to going to bed later and sleeping less, we are also not sleeping well. According to the American Psychiatric Association, more than 50 million people in the United States suffer from chronic sleep disorders such as insomnia and sleep apnea.

These issues directly reduce and disrupt deep sleep, shortening the critical window during which the glymphatic system works at peak efficiency. This, in turn, leads to greater waste accumulation in the brain. People reporting less adequate sleep and more sleep problems had a greater amyloid burden in Alzheimer’s disease-sensitive brain regions.

The accumulation of waste in the brain can lead to various symptoms. For instance, if this waste is not cleared and continues to accumulate, it can become difficult to stay clear-headed, Junge explained. “The most common symptom is a decline in cognitive function,” including memory loss, difficulty concentrating, and trouble managing complex tasks, Yang told The Epoch Times.

The long-term accumulation of these waste products can also affect mood, leading to anxiety, depression, or irritability. Yang further explained that this accumulation may be directly linked to neurodegenerative diseases, such as Alzheimer’s or Parkinson’s, as both conditions are closely associated with the buildup of beta-amyloid and tau proteins in the brain.

A 2021 longitudinal study with an average follow-up of 25 years and involving 7,959 older adults found that those who consistently slept less than six hours per night had a 30 percent higher risk of developing dementia than those who slept seven hours.

A 2019 study tracking more than 13,000 Dutch older adults over an average of eight years showed that declines in sleep quality and reduction in sleep duration increased the risk of developing Parkinson’s disease within the next six years by 76 percent and 72 percent, respectively.

Interestingly, there is evidence that your sleep posture may impact the brain’s waste clearance. The glymphatic system operates more efficiently in the side-lying position than when sleeping on the back or stomach. Prone is especially bade as it impairs cerebral blood flow and increases sympathetic nervous activity, triggering the release of stress hormones that suppress glymphatic function. In contrast, side sleeping reduces sympathetic tone, possibly improving glymphatic influx.

Some experts go so far as to suggest sleeping on the right side is better than the left. They postulate that with the heart positioned higher, blood circulation improves, and venous return increases, allowing the heart to work more efficiently while keeping sympathetic nervous activity low. Who knew that sleeping was so complicated? Sleep well tonight!

We all know sleep is good for you, but did you know it cleanses your brain? This is actually new information, but increases the evidence that getting more sleep may help prevent dementia as well as fatigue.

Flora Zhao, writing in The Epoch Times, tells us “As we fall asleep, the brain begins clearing out waste. It operates like a late-night laundry service, with all the water valves opened and washing machines running at full capacity to remove dirt from piles of clothes, flushing the wastewater into the drain. The brain continuously produces various wastes, and if these are not cleared regularly, we feel it. The signs can range from feeling foggy and fatigued to experiencing cognitive impairment.”

The human brain is one of the most metabolically active organs, accounting for about 20 percent of the body’s total energy expenditure. This high level of activity generates significant waste. Smaller by-products, such as carbon dioxide, urea, and ammonia, diffuse into capillaries and are cleared through the bloodstream. Larger neurotoxic proteins—including beta-amyloid and tau, both widely associated with an increased risk of Alzheimer’s disease, cannot be eliminated through the bloodstream alone due to their size.

In the past it was believed that the brain lacked a lymphatic system to remove waste and relied solely on internal mechanisms for clearance. However, in 2012, researchers discovered a specialized mechanism within the brain, analogous to the lymphatic system and capable of flushing out larger waste products from deep within the organ. This system was named the glymphatic system, a portmanteau of “glial” (referring to glial cells) and “lymphatic.” It is also known as the pseudo-lymphatic system.

Surrounding the arteries in the brain is a sheath-like structure, and cerebrospinal fluid flows through the space between the arteries and this sheath. During sleep, the brain’s blood vessels constrict, increasing the space between the vessels and the sheath, which allows more cerebrospinal fluid to flow in. As the arteries pulse, the cerebrospinal fluid is pumped through brain tissue, flushing out waste—such as beta-amyloid and tau proteins—from the deeper spaces between brain cells, eventually clearing it from the brain.

Sleep is divided into two states: rapid eye movement (REM) sleep and nonrapid eye movement (NREM) sleep. NREM makes up 75 percent of total sleep time and is further divided into three stages, N1, N2, and N3—each reflecting progressively deeper levels of sleep. During N3, brainwaves are at their slowest. During sleep, the body moves through the stages sequentially, forming a complete sleep cycle lasting around 90 minutes. Throughout the night, a person typically experiences four to five sleep cycles.

The glymphatic system becomes more active during sleep, especially during deep sleep, allowing for more effective waste clearance, said psychiatrist Dr. Jingduan Yang, founder of the Yang Institute of Integrative Medicine in Pennsylvania and a contributor to The Epoch Times.

In a mouse study published in Science, researchers used tracers to monitor changes in cerebrospinal fluid flow. They found that during sleep, the interstitial, or intervening, space expanded by more than 60 percent, and the tracer influx increased. The brain’s clearance rate of beta-amyloid doubled during sleep (or under anesthesia) compared with the awake state.

(For more on this subject, see Part II of this series next post.)

Cancer rates are rising in the young, Researchers have identified a focal point for the forces they suspect of driving up cancer cases in young people: the gut. They are searching people’s bodies and childhood histories for culprits.

Brianna Abbott, writing in The Wall Street Journal, tells us rates of gastrointestinal cancers among people under 50 are increasing across the globe.  In the U.S., colorectal cancer is the leading cause of cancer death in men under 50 and second for women behind breast cancer. Each generation born since the 1950s has had higher risk than the one before. 

“Everything you can think of that has been introduced in our society since really the 1960s, the post-World War II era, is a potential culprit,” said Dr. Marios Giannakis, a gastrointestinal oncologist at the Dana-Farber Cancer Institute in Boston.

Robert F. Kennedy Jr., President-elect Donald Trump’s pick for Health and Human Services secretary, has pointed to ultra-processed foods and chemicals in medicines and the environment. Cancer doctors share some of his suspicions about diet and exposure to contaminants such as microplastics, shards that make their way from packaging or clothing into our bodies through water and food. They are scrutinizing those and other potential hazards including “forever chemicals” and even light.

“We’re all concerned and want to do something quickly and act quickly, but we want to do so based on sound science,” said Dr. Andrew Chan, director of epidemiology at Mass General Cancer Center in Boston.

His team has found connections between early-onset colorectal cancer risk and obesity, consuming a lot of sugar-sweetened beverages and physical inactivity.  But those studies don’t prove a direct cause. Chan’s team is expanding its work to incorporate studies that track more people and analyze blood, tumor and stool samples. They will scour the results for potential carcinogens, then expose mice to them and see if cancers develop. They plan to first focus on obesity and alcohol, said Yin Cao, a cancer epidemiologist from Washington University School of Medicine in St. Louis, who co-leads the work with Chan.

Excessive alcohol use is linked with risk for early colorectal cancer, studies show, along with diets high in fat and added sugars. One study found people who ate more ultra-processed foods had a greater risk of precursors to colon cancer.

The group plans to test ways to lower risks, including whether prescribing weight-loss drugs including Ozempic can help prevent colorectal cancer. Another trial will assign some participants a healthier diet and study whether changes in the bacteria and pathogens in the gut, called the microbiome, affect their risk.

“There’s an  interplay most likely between the things we eat, the bacteria in the gut, and what those bacteria produce,” said Dr. Jordan Kharofa, a gastrointestinal-cancer specialist at the University of Cincinnati Cancer Center, who isn’t involved in the study.

Kharofa and other researchers have uncovered links to diets high in sulfur, which results from consuming lots of liquor and processed meat and few fruits and vegetables. Gut bacteria can turn that sulfur into hydrogen sulfide, which could inflame the colon and raise cancer risk.

 But some patients don’t fit that description at all. “They are very, very health conscious, and then they come into your clinic and they’re 33 and they’ve got stage-four colon cancer,” said Dr. Marwan Fakih, a gastrointestinal oncologist at City of Hope in Duarte, Calif. “There’s no question we’re missing something.”

Some researchers are looking at antibiotics, which disrupt the microbiome. One California team analyzed medical records and failed to find a solid link to broad-spectrum antibiotics, but the early results suggest long-term use could increase risk.

“We don’t have all the answers yet,” said Jane Figueiredo, a professor of medicine at Cedars-Sinai Medical Center in Los Angeles. “There might not be a magic bullet.”

All of this makes us realize there is much we still don’t know about the causes of cancer and therefore much we need to learn. Perhaps it makes sense to take another look at our diets and the processed foods that we consume, as Kennedy suggests.