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.

The recent cold-blooded murder of the UnitedHealth insurance executive has prompted a debate about the pros and cons of healthcare insurance. No one in their right mind should advocate murder of anyone, let alone because of a grievance with the healthcare industry. But it is good to better understand the healthcare system we live in, especially as it compares to alternatives in other countries.

There is no one better to assist us in that discussion than John C. Goodman, a healthcare economist who writes for The Independent Institute. Recently he reviewed and compared the healthcare system of Canada with the U.S. But before we compare different healthcare systems, we need to better understand problems that all healthcare systems face.

Three Problems in All Systems

Goodman says there are three problems with the doctor-patient relationship in all developed countries – regardless of the way the payment system is organized:

First, when a third party is paying the bill, neither the doctor nor the patient has any incentive to apply the kind of cost/benefit analysis that is normal in the purchase of any other good or service. In considering whether to obtain an expensive test (an MRI scan, e.g.), the incentive is to consider only the benefit. Since cost is irrelevant to the patient, a tiny benefit—no matter what the cost—is viewed as desirable.

Second, in a fee-for-service arrangement (such as exists in both the U.S. and Canada), the more services doctors perform, the higher their incomes. So, just as patients have an incentive to over-consume, doctors have an incentive to over-provide.

Third, there is malpractice liability, which is especially a problem in the U.S. A doctor who orders an unnecessary MRI scan faces no real penalty. But no matter how improbable, there is always a chance that a scan not ordered will fail to detect a problem that grows worse through time. Our legal system, therefore, provides incentives for too many tests and too many procedures, compared to a system in which costs would have to be justified by comparable benefits.

These are called perverse incentives in the language of economists. If they are not checked in some way, medical care becomes unreasonably expensive. That means higher premiums or higher taxes, depending on your healthcare system, or both. How do we check these perverse incentives?

The Canadian System

Canada checks these incentives by limiting resources. The typical Canadian general practitioner, for example, does not have radiology equipment and must send patients to a hospital for simple x-rays. The hospitals, in turn, operate under global budgets that limit spending, no matter what the level of demand. In other words, they put profits before patient care. This can happen in any healthcare system.

Canada ranks 25^th of 29 countries on the number of MRI scanners per person. As a result, the wait for a scan is almost three months, and the wait until final treatment is more than six months. The government has decided to prevent overuse of MRI scanners by severely restricting the number of scanners that are available.

Canada’s system of limiting heath care resources and forcing doctors to ration care has many undesirable characteristics. The system favors high-income over low-income patients. It favors white patients over racial minorities. It favors city dwellers over rural residents. It favors the politically connected over those without connections. Arguably, there is more inequality in access to health care in Canada than there is in the United States.

You might suppose that in countries that impose rationing, such as Canada and the U.K., doctors are forced to be more efficient—prioritizing resources so that the most promising procedures are done first. But studies by the RAND Corporation found that this isn’t so. In Canada and Britain, for example, scholars found just as much unnecessary care (as a percent of the total) as they found in the United Staes.

Then there is fraud, which is a special problem in government-administered programs. In Medicare and Medicaid, for example, fraud is estimated to consume at least $100 billion a year. Hospital upcoding (claiming a higher level of patient severity in order to obtain a higher insurance payment) is another problem. One study estimates that increased upcoding (relative to a decade earlier) was associated with $14.6 billion in hospital payments. Although doctors are the biggest critics of claim denials, hospitals are by far a bigger problem.

The Pre-Authorization Problem

As a doctor, I can tell you that pre-authorization is the bane of practicing medicine. It slows down your treatment of the patient and sometimes prevents you from doing what you know is needed. But there is a role for pre-authorization to hold doctors accountable for their treatment decision-making.

Goodman explains: “An important tool private insurers use to avoid unnecessary spending and inappropriate care is to require preauthorization for a particular drug, therapy, or procedure. Doctors tend to regard these procedures as burdensome and irksome. Yet only 7.4% of requests by patients in Medicare Advantage and Medicaid managed care plans are denied. Moreover, in the vast majority of appeals (83.2%), the initial denials are overturned.”

It’s easy to think other countries have better healthcare, but the facts don’t support that claim. All countries with government-provided healthcare (socialized medicine) suffer from the same problem: rationed care. If you can’t get in to see the doctor, or the government won’t allow the treatment he recommends, your “free healthcare” isn’t really free.

The public seems to understand this. Despite occasional complaints, more than two-thirds of Americans rate their health insurance as “good’ or “excellent.” And that holds for all kinds of insurance: employer plans, (Obamacare) marketplace plans, Medicare and even Medicaid. Even among people who say they are not in good health (and who, presumably, need medical care), a substantial majority give positive ratings to their health plans. Only a tiny percent rate their insurance as “poor.”