A new discovery about the lymphatic system has revolutionized the way we understand the brain.
Here in 2017, we tend to think we’ve got the human body pretty well figured out. There are still some mysteries, but the basic map is complete. Cardiovascular system, digestive system, endocrine system, muscular system, skeletal system, nervous system, vascular system, lymphatic system … I could go on, but you get the picture. We might not always know how or why things go wrong, but we know how the body works.
Or at least, we thought we did. But according to The Washington Post, a new discovery about the lymphatic system has revolutionized the way we understand the brain — and could have major implications on our lives.
“Kari Alitalo had studied lymphatic vessels for more than two decades. So he knew that this network, which carries immune cells throughout the body and removes waste and toxins, didn’t extend into the brain: This had been accepted wisdom for more than 300 years. “Nobody questioned that it stopped at the brain,” says Alitalo, a scientist at the University of Helsinki in Finland.”
Three years ago, Alitalo was attempting to create a more accurate map of the lymphatic system by genetically modifying mice’s lymphatic vessels with a jellyfish gene, to make them glow when hit with a certain wavelength of light. So he was shocked when their heads started glowing, too. He figured he had made an error, so he started over — with the same result.
This was the beginning of a major breakthrough in lymphatic system research. Not only do lymphatic vessels extend to the brain, but there are two networks of them. The one that leads into and surrounds the brain is known as the lymphatic system for the brain, while the one inside the brain itself is called the glymphatic system. The “g” refers to “glia,” which is the kind of neuron that the lymphatic vessels in the brain are composed of.
For a system that was just discovered, the glymphatic system is incredibly important. It carries cerebrospinal fluid and immune cells into the brain, and cleans out cellular trash. When the glymphatic system malfunctions, the brain can become clogged with toxins and inflammatory cells, which may play a significant role in the development of neurodegenerative illnesses like Parkinson’s and Alzheimer’s.
Scientists have been making rapid discoveries about the crucial role of the glymphatic system in maintaining brain health, finding evidence for glymphatic malfunction in autoimmune disease, migraines, and even ocular degeneration. But they’ve also identified a key element of glymphatic performance: sleep.
In mice (whose glymphatic systems are very similar to humans), the vessels process twice as much fluid in sleep than in wakefulness. And sleep position matters; standing or sitting inhibit glymphatic flow, as does stomach sleeping. The most effective positions are back and side.
Although sleep is the best way to improve your brain’s trash-removal process, a Chinese study suggests that omega-3 fatty acids can help, as can deep breathing. But researchers are experimenting with compounds that might foster lymphatic vessel regrowth, which could open up a world of new treatments for Alzheimer’s or other neurodegenerative diseases. Alitalo is optimistic — his trials on pig lymphatic vessels were successful, and he’s moved on to work on repairing damaged mice lymphatic vessels.
In the meantime, a new antibody therapy called aducanumab that targets Alzheimer’s disease has shown promising results in its first clinical trial. It targets brain build-up likely caused by glymphatic system malfunction, and showed a significant reduction in patients who received monthly infusions for a year. If the larger clinical trials are successful, aducanumab will become the first Alzheimer drug to ever reverse signs of the disease.
Obviously, it’s better to keep your glymphatic system functioning well than have to clean up the detritus when it breaks down, so make sure you sleep enough, eat your fish, and breathe deeply. Your brain will thank you.