Sea moss supplements are promoted as being good for thyroid, digestive, skin and immune health. What’s the evidence to support the claims?
Sea moss supplements are promoted as being good for thyroid, digestive, skin and immune health. What’s the evidence to support the claims?
Related listening:
The Carrageenan Controversy (Nutrition Diva #276)
Research references:
Effects of kelp supplementation on thyroid function in euthyroid subjects - PubMed (nih.gov)
Risks and benefits of consuming edible seaweeds | Nutrition Reviews | Oxford Academic (oup.com)
Hi and welcome to the Nutrition Diva podcast. I’m your’re host Monica Reinagel and today I want to respond to several listener questions I’ve gotten recently about Irish sea moss.
Before I jump into that, I wanted to answer a quick question that camecome in from Donna in response to my recent episode on collagen. Donna was wondering whether plain gelatin packets that you buy at the grocery store are a good source of collagen.
Both gelatin and collagen supplements are derived from the collagen protein found in animal connective tissues, bones, and skin. The main difference lies in their processing. Gelatin is produced by partial hydrolysis of collagen, resulting in a product that gels or thickens when cooled after being heated. Hydrolyzed collagen, used in collagen supplements, is further broken down into smaller peptides, which do not gel and are believed to be more easily absorbed by the body. Both can contribute to dietary protein intake and provide similar amino acids. And gelatin is certainly less expensive. However, it may not provide the same benefits as a collagen supplement that has been formulated to address a specific concern.
And now, let’s get into sea moss. Celine writes, “My sister keeps touting the benefits of Irish sea moss supplements. What are the pros and cons of this supplement, especially for women? Many of the purported benefits addresses issues I do not currently have, but could this supplement help prevent them in the future?”
Irish sea moss is a red algae that grows along the rocky coastlines of the North Atlantic Ocean. It is commonly found on the eastern coasts of Canada and the United States, particularly from Maine down through Massachusetts. In Europe, sea moss grows extensively along the coasts of Ireland (hence the name Irish moss), Great Britain, and the coastal regions of France and Iceland.
It was traditionally used in soups and broths to boost nutrition and improve texture. But its popularity as a supplement has surged recently. It’s being touted for a wide range of health benefits—from boosting immune function and fertility, to improving digestion, supporting thyroid health, and beautifying the skin. So let’s take a closer look at the evidence to support these various claims.
Like most sea vegetables, sea moss is low in calories but rich in various minerals, like potassium, calcium, and magnesium. It’s also got some soluble fiber. While other sea vegetables are higher in protein and Vitamin A, sea moss is particularly rich in iodine.
Sea moss is a natural source of carrageenan, a natural compound that has a thickening or gelling action in liquids. This is one of the reasons that sea moss was traditionally used in soups and stews. But that thickening or gelling action also makes carrageenan useful as a food additive. You’ll find it in things like yogurt, cottage cheese, non dairynondairy milk alternatives, puddings, salad dressings, and as a vegan alternative to gelatin in gummy candies.
But there has also been some controversy around this additive. While the FDA considers it safe when used as intended, there has been ongoing debate about its effects on digestive health. Some animal studies and in vitro research have suggested that carrageenan can cause inflammation and gastrointestinal ulcerations, and some consumers choose to avoid carrageenan due to these concerns.
For more on this, please see Episode #276
Let’s turn to some of the health claims Celine asked about. Sea moss is said to promote thyroid health and, by extension, fertility (which is dependent in part on thyroid health.). This basis for this claim is sea moss’ iodine content.
Iodine is crucial for the production of thyroid hormones, which regulate metabolism, support neurological health and reproductive function, among other vital roles. People who aren’t getting enough iodine can develop hypothyroidism—leading to symptoms like fatigue, weight gain, and even depression. However, too much iodine can be just as harmful to the thyroid as too little. And some thyroid issues have nothing to do with iodine.
For those who are not deficient, more iodine does not equate to better thyroid health or reduce your risk of future thyroid disease. And iodine deficiency is pretty rare in parts of the world where salt is commonly fortified with iodine. Even if an iodine deficiency is confirmed, it’s safer to use a supplement where the dose can be accurately measured and controlled, rather than relying on natural sources like sea moss, where iodine content can vary widely. And obviously, this would be best done in consultation with a healthcare provider.
Another popular claim for sea moss is its benefits for digestive health. These claims are largely based on its content of soluble fiber, which can help prevent constipation, plays a role in cholesterol management and can help stabilize blood glucose levels. Soluble fiber can also promote a feeling of fullness, potentially aiding in weight management.
While the soluble fiber in sea moss may support digestive health, it's just one of many sources available—and not necessarily the most special or effective. Oats, apples, beans and legumes, flax and chia seeds are all good food sources of the same types of soluble fiber, along with many other nutrients.
Another alluring claim for sea moss is its supposed ability to boost immune function. To be sure, its is a good source of vitamin C, zinc, and iron, all nutrients that support a healthy immune system. But again, while these nutrients are undoubtedly beneficial, they are not unique to sea moss. Many other foods can provide these same immune-supportive benefits, often in more substantial amounts.
Direct scientific research linking sea moss to improved immune function is sparse. Most of the studies are preliminary and have been conducted in vitro or on animals, making it difficult to draw concrete conclusions about its effects on human immune health.
And finally, sea moss is often touted as a miracle ingredient for everything from hydrating the skin to reducing wrinkles and treating conditions like eczema and psoriasis. And, the vitamins and minerals in sea moss may support skin health. But, again, sea moss is not a unique or particularly potent source and the impact of consuming sea moss on skin health has not been well researched. Most claims are based on anecdotal reports or simply reflect the known benefits of its individual components, rather than direct study of sea moss itself.
Having thrown cold water on many of the claims being made for sea moss supplements, I still think there’s a place for sea moss and other sea vegetables as a fun way to add nutritional and culinary variety to your diet. Here are some tips on how to use sea moss and where to find it.
Sea moss can often be found in health food stores, often sold as dried whole seaweed, gel, or powder. For other sea vegetables like nori, wakame, or kelp, Asian markets are a treasure trove, as these ingredients are staples in many Asian cuisines. If you can’t find a good selection locally, online retailers are another convenient option.
You can use sea moss to make a gel which can be added to salad dressings or sauces to create a thicker texture and add some nutritional value. You can also put dried sea moss or kelp directly into broths, soups, and stews. They will thicken the liquid somewhat and add a savory, umami flavor. Rehydrated or fresh wakame can be dressedcan dressed with a simple dressing of sesame oil and vinegar for a delicious seaweed salad. And finally, dried nori sheets can be used to wrap sushi, of course, but they also make great snacks when toasted lightly with a sprinkle of salt.
Thanks to Celine for kicking off today’s discussion of sea moss. If you have a question you'd like me to answer, you can email me at nutrition@quickanddirtytips.com. You can also leave me a message at 443-961-6206
That's all for this episode. Thanks for listening! I'll see you next week.
Nutrition Diva is a Quick and Dirty Tips podcast and is supported by a fantastic team, which includes Brannan Goetschius, Nathan Semes, Davina Tomlin, Holly Hutchings, Morgan Christianson, and Kamryn Lacy.