Eating sea squirts reverses signs of cognitive decline and aging

SUZHOU, China — Adding sea squirts to your diet could help reverse the signs of aging in your body and the brain, a new study reveals. A team from China and the United States found that supplements containing sea squirts — or ascidians — dramatically improved the cognitive health of mice. It even reversed the graying of their fur!

What are sea squirts?

Ascidians are part of an invertebrate family called Ascidiacea. They’re marine animals that often look like potato-shaped tubes which often live in reefs, pier pilings, rocks, or even a ship’s hull.

As a food, people can eat these organisms either raw or cooked. They’re a regular ingredient in both Korean and Japanese cuisine. What makes them increasingly important for scientists is the fact that they contain substances called plasmalogens. These are naturally occurring substances which are vital to our bodily processes, including in the heart, brain, and immune system.

However, as people age, the number of plasmalogens in the body decreases. Researchers say having fewer plasmalogens is a characteristic doctors see in several different neurodegenerative conditions, including Alzheimer’s and Parkinson’s disease.

Reversing the aging process

Study authors examined the possible benefits of eating sea squirts by adding plasmalogens to the diets of older mice. Results show the supplements improved both the learning abilities and physical appearance of the aging mice. It’s the first time scientists have shown the positive effect of plasmalogens on the aging brain.

“Our research suggests that plasmalogens may not just stop cognitive decline, but may reverse cognitive impairments in the ageing brain. Additionally, aged mice fed with the plasmalogens grow new black hair that is thicker and glossier than aged mice not fed the supplement,” says corresponding author Professor Lei Fu from Xi’an Jiaotong-Liverpool University in a media release.

Researchers tested this boost by using a Morris water maze, which features a pool of water and a platform. Typically, mice don’t like to swim, so they’ll seek out a dry place to climb on to and rest. For five days, the team tested the animals’ ability to remember where this platform was and how fast they swam to it.

As mice get older and their cognitive abilities slow down, it normally takes them longer to find the platform in comparison to younger mice. During this study, researchers found older mice consuming plasmalogens performed just as well as younger mice. They also found the platform faster than another group of older mice who did not take the plasmalogen supplement.

What are plasmalogens doing to the brain?

While examining the plasmalogen-fed mice, study authors discovered that they had a higher number of synapses — the connections between neurons in the brain. These synapses were also of a much better quality than the ones in older mice not taking the sea squirt supplement.

Researchers explain that synapses are an integral part of a person’s neural networks and are vital to learning and memory. While the synapses are very plastic when we’re children, they deteriorate over time — leading to cognitive impairment in old age.

Additionally, the team found plasmalogen supplements lowered levels of brain inflammation in these mice. Previous studies have shown that brain inflammation is a major contributor to neurodegeneration, causing the brain’s immune system to overreact and attack healthy tissue.

How do plasmalogen supplements improve health?

It’s still unclear how this pill exactly benefits cognitive health, but Prof. Fu says there are a number of possibilities.

“We found that plasmalogens significantly increase the number of molecules that aid the growth and development of neurons and synapses in the brain. This suggests that plasmalogens can promote neuroregeneration.”

“There is also an increasing body of evidence that plasmalogens directly affect the structural properties of synapses. Plasmalogens may increase the fluidity and flexibility of synaptic membranes, affecting the transmission of impulses between neurons,” the study author adds.

Researchers note that this substance in sea squirts may also benefit the brain by improving our gut health first.

“Some studies have shown that dietary plasmalogens affect the microorganisms in the gut. It has been widely reported that the connection between the organisms in our gut and our brain influences neurodegeneration. It may be the plasmalogen’s effect on this connection that causes the improvements in learning and memory seen in this study,” Fu says.

“For the first time, we show that plasmalogen supplements might be a potential intervention strategy for halting neurodegeneration and promoting neuroregeneration,” Prof. Fu concludes. “The oral intake of plasmalogens could be a feasible therapeutic strategy to improve cognitive function in older people.”

The study is published in the journal Frontiers in Molecular Biosciences.