Ascophyllum nodosum, a type of brown seaweed, has been researched for its potential role in supporting oral health, including gum (periodontal) health. Several clinical studies have examined oral care products containing extracts of Ascophyllum nodosum, particularly regarding their effects on dental plaque and gingival inflammation. The evidence suggests that supplementation with this seaweed can reduce plaque formation and bleeding scores, which are key indicators of gum health.

For example, randomized controlled trials have shown that the use of Ascophyllum nodosum supplements in humans led to statistically significant reductions in plaque index and gingival bleeding compared to placebo. The mechanism is thought to involve polyphenols and other bioactive compounds in the seaweed that may inhibit bacterial adhesion, decrease inflammation, and modulate the oral microbiome.

While these results are promising, the number of high-quality studies is limited, and most have been of relatively short duration and small sample size. Additionally, most products studied have included other ingredients, making it difficult to attribute effects solely to Ascophyllum nodosum. Nonetheless, the existing clinical evidence provides moderate scientific support for its use in supporting gum health, justifying an evidence rating of 3 out of 5.