If you believe the headlines, seaweeds can do almost anything from storing tons of carbon and stopping cows from belching methane, to making biofuels and renewable plastics – all while sustaining vibrant coastal ecosystems and feeding communities.
Add to that list their potential wound-healing properties and possible anti-aging effects, and it's no wonder the seaweed farming industry is booming.
A new study adds to that fanfare, with lab experiments based on human-like skin cells revealing extracts from two brown seaweeds can inhibit reactions linked to skin aging and boost collagen levels.
"We found that extracts from South Australian brown seaweed have huge potential to be used to help slow the effects of aging on our skin," says study author Wei Zhang, a biochemical engineer at Flinders University in Adelaide.
The ecological significance of seaweeds and their importance as a food source cannot be understated, though it's fair to be skeptical of other claims until we see the evidence.
In this study, collagen levels were measured in the culture media of human skin cell lines, grown in plastic dishes and treated with powdered seaweed. That's a far cry from human trials.
Still, early findings suggest there is reason to be optimistic.
The brown seaweeds Ecklonia radiata, Cystophora moniliformis, and Cystophora siliquosa, were all subjected to a battery of tests and analysis. The two Cystophora species stimulated the lab-grown cell lines into producing more collagen, one of the two structural proteins that give youthful skin its plumpness. Tests didn't show signs that production of the second protein, elastin, was affected.
The researchers also tested their powdered seaweeds in chemical mixtures to evaluate their effect on protein glycation, a normal reaction involving proteins and sugars that yields products that accumulate in aging skin.
C. moniliformis and C. siliquosa inhibited glycation activity in these rudimentary experiments, though researchers haven't had much success targeting this pathway before. Previous anti-glycation candidates have shown low effectiveness and even some undesirable side effects in later trials.
"So far anti-glycation agents haven't been strong enough to have a major impact on anti-aging," says Zhang, "so our discovery is really exciting as we can see the potential to develop stronger anti-glycation extracts from brown seaweed."
If the researchers are successful in developing a safe product, randomized clinical trials would be needed to rigorously test the purported benefits of seaweed extracts, and ensure their safety in humans.
The results of those studies might show that seaweed supplements aren't always as effective as hoped.
For instance, seaweed extracts have been trialed as a dietary supplement for people with inflammatory skin conditions. But only a fraction of participants in that trial saw any improvement in their condition – which might have been down to other dietary factors that the researchers couldn't control.
Past studies have shown that the conditions in which seaweeds are cultivated can impact their anti-oxidant and anti-inflammatory properties.
It's also unclear at this stage without further development or testing how the seaweed extracts would be used, as a topical product applied to the skin or as an oral supplement.
Either way, much more research would be needed to purify and formulate a product that contains relevant compounds in useful yet safe concentrations. The concentrations used in these cell studies might not be appropriate for human use.
As Emma Beckett, a food and nutrition scientist at the University of Newcastle reminds us, taking supplements doesn't necessarily translate into perceivable benefits for our skin, either. She says a better approach might be to protect your skin from sun damage, eat a healthy diet, and avoid cigarettes.
The study has been published in Algal Research.