The Link Between Your Immune System, Brain, and Alzheimer’s

We’ve seen exciting developments in Alzheimer’s research this year, and a new discovery could move us one step closer to a cure. (Photo: Getty Images)

Researchers from the University of Virginia School of Medicine have discovered that the brain is directly connected to the immune system through vessels that scientists previously didn’t know existed.

The discovery happened during a mouse study when Antoine Louveau, PhD, developed a method to place a mouse’s meninges (the membranes covering the brain) on a single slide so they could be examined as a whole. In the process, he noticed patterns on the slides that showed immune cells had reached the meninges through vessels. With testing, he discovered the vessels were linked to the lymphatic system, which is part of our immune system.

On the left, our previous understanding of the lymphatic system, which is part of the immune system. On the right, the vessels that connect the lymphatic system to the membranes covering the brain. (Illustration: University of Virginia School of Medicine)  

Previously, scientists were aware that the surroundings of the brain contained immune cells but didn’t know how they entered and left the brain, Louveau explains to Yahoo Health. Now they can see that the brain is like every other organ in the body, connected to the immune system.

Organs in our bodies are connected to the lymphatic system, which transports lymph, a fluid that contains white blood cells that help rid our bodies of toxins. The lymphatic system essentially helps keep us healthy.

Related: From the Brain to the Immune System, How Stress Pirates Your Whole Body

“The brain was thought not to have that connection, but we discovered the brain works the same way as other organs,” says Louveau.

Now, he says, these vessels may play a large role for every neurological disease that has an immune component to it. As a result, scientists can look at neurological diseases such as Alzheimer’s, meningitis, and multiple sclerosis differently. “We think it’s highly significant because it’s going to change how we look at neurological diseases,” he says.

Related: Study Finds Link Between Immune System and Alzheimer’s Disease

As for the Alzheimer’s connection, scientists already know that people suffering from the disease have protein accumulation in the brain. But Louveau says that protein may accumulate because it’s not being properly removed by the lymphatic vessels.

Alzheimer’s disease is the sixth leading cause of death in the U.S. and it’s the only cause of death in the top 10 in America that can’t be prevented, cured, or slowed, according to the Alzheimer’s Association. Researchers have been working for years to understand the mechanisms of the disease. While new discoveries have been made that can help with early detection, a cure still alludes them.

But does this mean people with a weaker immune system may be at a greater risk of developing a neurological disease? Louveau says they don’t know right now, but they’re working on it. His team plans to delve more into the link between Alzheimer’s and the vessels, as well as how they can affect meningitis.

“We now have a physical link between the brain and the immune system, and that’s going to help us understand better what’s happening in those areas,” he says.

While research on the subject is ongoing, he says he hopes his findings may eventually help lead to a cure for various neurological diseases. In the meantime, he says, he’s hopeful that the vessels will simply help scientists better understand what triggers these diseases.

Read This Next: The Strange Way the Seasons Change Your Genes and Immune System

Let’s keep in touch! Follow Yahoo Health on Facebook, Twitter, Instagram, and Pinterest. Have a personal health story to share? We want to hear it. Tell us at