Endocrine Wellness

Little more about Gotu Kola!

For several years now I have been emphasising the importance of improving microvascular health in patients with, or at risk of, age-related macular degeneration (AMD), using Centella asiatica (gotu kola) as a central component of this strategy.

Now a recent randomised, double blind, placebo-controlled trial from Korea has evaluated a standardised extract of gotu kola (300 mg/day, standardised to asiaticoside at 14.1 mg/g) over 6 months in 80 adults aged 45 to 65 years with low baseline macular pigment optical density (MPOD). The study was methodologically sound, with good blinding, balanced baseline characteristics, low attrition, and both per-protocol and intention-to-treat (ITT) analyses reported.

The primary finding was a significant and progressive increase in MPOD compared to placebo. By Day 180, changes from baseline showed large between-group effect sizes: right eye (+0.06 vs 0.00; d = 1.26), left eye (+0.02 vs −0.02; d = 1.00), and average MPOD (+0.04 vs −0.01; d = 1.96), all highly statistically significant. The letter d above refers to Cohen’s d, a standardised measure of effect size. A value of 1.00 or higher, as seen in this study, represents an extraordinarily large clinical effect.

Benefits were already evident by Day 120. A responder analysis (defined rather permissively as any increase in MPOD) showed 94.7% responders in the treatment group versus 32.4% in placebo. Safety was reassuring, with no serious adverse events and no clinically meaningful changes in laboratory or vital parameters.
MPOD is a clinically useful surrogate marker of macular resilience, reflecting the concentration of lutein, zeaxanthin, and meso-zeaxanthin in the central retina. Higher MPOD is consistently associated with better visual performance (particularly contrast sensitivity, glare recovery) and a lower risk or slower progression of AMD. However, it is a surrogate marker rather than a direct measure of vision.

In a field where meaningful interventions are scarce, these findings signal a compelling new advance, showing that a non-carotenoid containing herb can measurably enhance macular resilience and potentially open an entirely new therapeutic pathway for AMD prevention and treatment.

For more information see: https://pubmed.ncbi.nlm.nih.gov/41901080/