The study, funded by B&S Corporation Co., Ltd., which manufactures and markets scallop plasmalogen, evaluated memory and brain health in 66 Japanese adults, with below-average verbal memory, who took the supplement for 12 weeks.
“Overall, dietary sPls may have the potential to support cognitive function in this population, although further studies are needed to confirm these findings, establish their generalizability, and evaluate long-term safety,” the Japanese researchers wrote in Frontiers in Nutrition.
What are plasmalogens?
Plasmalogens are a specialized type of phospholipid (fat) that represent around 20% of total phospholipids in humans. Plasmalogens serve as essential building blocks for cellular membranes and are abundant in nervous, immune and cardiovascular cells.
Recent evidence suggests that plasmalogens act as endogenous antioxidants, protecting cells from oxidative damage, particularly in tissues with high membrane trafficking, such as the brain. They may play an important role in membrane fluidity, synaptic function and neurotransmitter release. Plasmalogen deficiency has been associated with severe diseases, including neurological and neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease.
As such, plasmalogen replacement therapy is an emerging therapeutic concept.
The researchers notes: “In animal studies, Pls [plasmalogen] administration has been shown to suppress inflammation-related microglial activation, reduce amyloid deposition and neuronal loss, and improve cognitive performance”.
However, effective delivery is challenging due to chemical instability, low oral bioavailability, and biological barriers such as the blood–brain barrier.
In addition to scallops, which the current researchers used as a supplement source, plasmalogens are present in other food sources such as muscle from pigs, salmon, mussels, cattle, and chicken, as well as in hen eggs and brown algae.
Study details
The study was a randomized, double-blind, placebo-controlled trial with a parallel-group design.
The participants were 66 Japanese adults, aged over 40 years, with verbal memory performance below the age-matched normative mean and no clinically diagnosed disease.
They were randomly assigned 1 mg daily of purified sPls extracted from Mizuhopecten yessoensis, a type of Japanese scallop, or placebo for 12 weeks.
The researchers assessed memory scores and 16 other relevant cognitive domains using appropriate methods at baseline and the end of the 12-week study.
They also evaluated plasma brain-derived neurotrophic factor (BDNF) as a marker of brain health.
The results showed that verbal memory scores were significantly higher in the sPls group than in the placebo group at 12 weeks, suggesting a “moderate” effect. The supplement group also showed higher attention scores than the placebo group.
The researchers conducted a subgroup analysis by educational attainment and found that participants without a bachelor’s degree had higher memory scores in the supplement group, whereas no differences were observed among those with a four-year university degree or higher.
Although negative correlations were observed for plasma BDNF and working memory, there were no significant differences between groups.
As far as safety was concerned, the researchers observed higher cholesterol levels more frequently in the supplement group but said, “this difference was not clinically meaningful.”
Because the between-groups effect size had “a relatively wide confidence interval and a p-value close to the conventional threshold for statistical significance”, the study noted that the results should be interpreted with appropriate caution and confirmed in larger studies.
Source: Frontiers in Nutrition; doi: 10.3389/fnut.2026.1906996; “Orally administered scallop-derived plasmalogens improve cognitive function in healthy middle-aged and older adults: a randomized, double-blind, placebo-controlled trial.” Authors: M. Fukuchi et al.
