Seaweed Supplement May Help Build Muscle and Reduce Body Fat

La Trobe University researchers have found that fucoidan, a natural ingredient from brown seaweed, may help people get more from resistance training by improving body composition and performance during high-intensity exercise. While all participants became stronger through training, those taking fucoidan gained extra benefits, including more lean muscle, lower body fat and improved power.

Led by Dr Stephen Cousins from the Holsworth Biomedical Research Centre, the study was conducted in collaboration with Tasmania-based marine biotechnology company Marinova, bringing together academic and industry expertise in fucoidan research and its potential applications for human health and exercise performance.

The study involved 20 healthy, active adults who were randomly assigned to receive either fucoidan or a placebo while completing the same six-week supervised resistance training program. Researchers measured changes in strength, exercise performance, body composition and several blood markers.

Both groups improved their squat strength by a similar amount, showing that fucoidan did not increase strength beyond the gains normally expected from resistance training. However, participants taking fucoidan produced more power during a 30-second high-intensity cycling test, suggesting the supplement may help with short bursts of intense exercise.

The fucoidan group also saw positive changes in body composition. Participants gained lean muscle and reduced their body fat percentage over the six-week program, while these improvements were not seen in the placebo group. These findings support earlier laboratory and animal studies suggesting fucoidan may help the body use and store energy more effectively.

“The most exciting finding was that participants taking fucoidan not only gained lean muscle and reduced body fat, but also improved their ability to perform short bursts of high-intensity exercise. These are outcomes that are important for both athletic performance and overall health.” said lead researcher, Dr Stephen Cousins.

Researchers did not find meaningful changes in blood markers such as cholesterol, cortisol or inflammation. This suggests the supplement's benefits were mainly related to body composition and exercise performance rather than broader health measures.

Importantly, this is the first human study to show that fucoidan may improve both body composition and high-intensity exercise performance when combined with resistance training. The findings highlight fucoidan's potential as a natural, plant-based supplement for people looking to support their fitness and metabolic health.

The Holsworth Biomedical Research Centre, a key partner of La Trobe Rural Health School, is transforming biomedical research into real health outcomes for regional and rural communities.

Learn more about this recent study here.