Laminaria or brown algae is another seaweed that is distinct from the more commonly talked about kelp. Both are nutritional sources of iodine but their medicinal properties are different. What makes the brown algae different is substance called fucoidin.
Iodine occurs naturally in sea vegetables which is extremely important for thyroid health. Iodine deficiency is very common since our diets are often very low in sea vegetables. The most common dietary source is salt but the refining process often removes other trace minerals. Other body systems that rely on iodine are the immune system and breast tissue. Because it may enhance thyroid function lab tests should be used to monitor thyroid activity initially.
Fucoidin has been shown to have many medicinal properties. Its anticancer properties are currently being investigated. It also seems to have immune modulating effects and may be helpful to during the cold and flu season. In the gut it may help prevent the growth of a H pylori. It also seems to show anti inflammatory properties and may be a supportive nutritional agent for kidney and liver disease in diabetics.
The brown algae also have soothing properties on the digestive system. Coating the stomach it may help reduce heart burn.
Reference: Therapies from Fucoidan: An Update