Effects of Konjac glucosylceramides on cognitive function in cognitively unimpaired older adults with subjective cognitive concerns: a randomized, double-blind, controlled pilot study.

In 30 seconds

This 24-week randomized, double-blind, placebo-controlled pilot trial enrolled 40 cognitively unimpaired adults aged 60–80 years who reported subjective memory or cognitive decline. Participants received placebo or one of three daily doses of konjac-derived glucosylceramide (kGlcCer). The medium-dose group improved significantly more than placebo on WAIS-IV Coding. Other cognitive and amyloid-biomarker changes were exploratory and did not show consistent placebo-adjusted differences. No safety concerns were observed during the study. The trial was not powered to establish efficacy.

Key findings

• The medium-dose kGlcCer group showed significantly greater improvement in WAIS-IV Coding performance than the placebo group.
• High-dose participants improved on several verbal-memory and word-pair learning measures, but consistent placebo-adjusted differences were not observed.
• In participants with low baseline amyloid burden, high-dose kGlcCer was associated with favorable changes in amyloid-related biomarkers.
• No safety concerns related to kGlcCer intake were observed during the 24-week study.

Why it matters

The findings offer preliminary evidence that a dietary bioactive lipid may affect selected cognitive measures in older adults with subjective cognitive concerns. The distinction between within-group improvement and placebo-adjusted benefit is important: only the Coding result showed significant superiority over placebo, while other findings remain exploratory. Larger trials are needed to determine whether these signals are reproducible and clinically meaningful.

What to keep in mind

This was a small exploratory pilot trial and was not powered to establish efficacy. Consistent between-group differences were not observed across cognitive outcomes.