Aged mice fed concentrated extracts of a compound found in sea squirts showed a reversal of several classic signs of aging, according to a study led by researchers at Xi'an Jiaotong-Liverpool University, Stanford University, Shanghai Jiao Tong University and the University of Chinese Academy of Sciences, published this month.
The compound, plasmalogen, is a class of lipid the body already produces and that makes up roughly a fifth of all phospholipids in humans, playing a role in heart, brain and immune health. Levels of it decline naturally with age. Researchers extracted concentrated plasmalogens associated with sea squirts — filter-feeding marine invertebrates eaten in parts of East Asia — and fed them to older mice at doses far above what a typical seafood meal would provide.
Treated mice showed improved memory and learning in maze and object-recognition tests, and their neurons formed stronger connections, the researchers reported. Inflammation markers dropped, and microglia — the brain's resident immune cells, which become overactive and can damage neurons with age — quieted down. A more visible effect: mice fed the supplement grew back thicker, glossier and darker coats, while untreated control animals continued turning gray and thin-haired.
How reversible is it, really?
The findings add to a small but growing body of research into plasmalogens as an anti-aging target, including earlier work on plasmalogen supplementation and cognition covered by outlets such as The Conversation and Inverse. Researchers stressed that mouse studies routinely fail to replicate in humans, and that the doses used were concentrated well beyond dietary levels — eating sea squirts at the sushi counter is unlikely to reproduce the effect.
Still, scientists in the field said the range of reversed markers, spanning brain, coat and inflammation measures in a single study, makes plasmalogens worth pursuing as a supplement candidate. Sea squirts, also called tunicates, are already harvested commercially as food in South Korea and Japan, giving researchers a readily available natural source to study rather than needing to synthesize the lipid from scratch.
The team said the next step is testing whether the effects hold up in longer trials and, eventually, whether synthetic or dietary plasmalogen supplements show any measurable benefit in humans — research that has not yet begun. For now, the results stand as a mouse study only, with human trials neither designed nor scheduled.