Could ‘sea squirts’ hold a clue to healthier ageing?

Grey hair, fading memory and a little more creaking around the edges are familiar signs of getting older. But could a rather strange-looking marine animal offer scientists clues about whether some aspects of ageing might one day be slowed – or even reversed?

Researchers have been studying compounds called plasmalogens, which are found naturally in the human body as well as in high concentrations in “sea squirts”.

Not familiar with them? These unusual marine animals belonging to the class “Ascidiacea” aren’t commonly found on Malaysian menus. They are more frequently eaten in parts of Japan and South Korea.

According to a recent report on the study, plasmalogen supplements were linked with better memory, healthier connections between brain cells and less inflammation in the brain.

And in one of the study’s more eye-catching findings, older recipients of the supplements also grew thicker, glossier and darker hair.

Before anyone starts searching seafood markets for an anti-ageing dinner, there is a major catch: the research was conducted in mice, not people.

The potential in plasmalogens

Plasmalogens are a type of fat molecule that forms part of cell membranes. They are particularly abundant in the brain, heart and immune cells, but their levels tend to decline with age.

Lower levels have also been observed in neurodegenerative conditions including Alzheimer’s and Parkinson’s disease, although that does not necessarily mean the decline causes those diseases.

For the study, the researchers gave aged female mice plasmalogens derived from sea squirts over a two-month period. To test memory and learning, the mice were then put through a water maze in which they had to remember the location of a hidden platform.

Older mice receiving the supplements performed better than untreated ageing mice and, in some measures, behaved more like younger animals. Their brains were found to have more and healthier-looking synapses, which allow nerve cells to communicate with one another.

The supplemented mice also showed less activation of microglia, immune cells in the brain that can contribute to inflammation. The researchers believe reducing this inflammation may have helped preserve the brain’s ability to communicate and form new connections.

The study further found signs of increased synaptic plasticity and neurogenesis – essentially, processes involved in maintaining, adapting and forming nerve cells and their connections.

Exactly how plasmalogens produced these effects remains unclear. One possibility is that they help maintain the flexibility of cell membranes, making communication between nerve cells more efficient.

The researchers have also suggested that plasmalogens might influence the gut microbiome, which in turn communicates with the brain through the so-called gut-brain axis.

Perhaps the most visually striking result was not in the brain at all: older mice receiving plasmalogens grew thicker and glossier coats, with new dark hair appearing compared with untreated animals.

While intriguing, it does not mean sea squirts are a cure for ageing or even grey hair.

Indeed, animal studies are useful for uncovering biological mechanisms, but many treatments that work impressively in mice fail to produce the same results in humans.

The experts would still need clinical trials to establish whether plasmalogen supplements improve cognition in people, what doses might be safe and effective, and whether long-term use carries any risks.

So, for now, sea squirts are less a fountain of youth than an unusual clue in the continuing scientific puzzle of how our brains age.

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