Fucoidan is a sulfated polysaccharide that occurs naturally in several types of brown seaweed, one of the world’s most widespread forms of marine algae. Polysaccharides are carbohydrates made up of multiple monosaccharides, the basic building blocks of all carbohydrates. In vitro studies have produced promising evidence that fucoidan may have health benefits for humans, according to Memorial Sloan-Kettering Cancer Center. While edible seaweeds are a mainstay of Far Eastern cuisines, they are not yet that common in Western dining.
Eating foods rich in fucoidan can help your immune system fight off infection and disease. One of the most powerful health benefits claimed for fucoidan is its functional support of the body’s immune system, according to clinical nutritionist Ken Babal, author of “Seafood Sense.” He cites numerous studies that have focused on this aspect of fucoidan’s medicinal properties. Babal notes that one researcher likened the nutritional makeup of fucoidan to that of breast milk, “the most perfect immune-supporting food known.” The polysaccharide gives the immune system a big boost by enhancing phagocytosis, the process through which white blood cells attack and destroy pathogens, such as bacteria and viruses. Fucoidan also increases the number of mature white blood cells that are circulating in your body, thus bolstering the first line of defense against infection and disease.
A diet high in fucoidan may also help prevent and treat cancer. Memorial Sloan-Kettering Cancer Center says several laboratory studies have shown that fucoidan has medicinal properties that could be helpful in combating some forms of cancer but cautions that human data thus far are lacking. The center cites one study that showed fucoidan appears to inhibit the spread of cancerous cells by preventing the adhesion of tumor cells to the extracellular matrix. In another study, fucoidan induced apoptosis, or programmed cell death, in human T-cell leukemia virus type I, or HTLV-1, that causes adult T-cell leukemia. The polysaccharide paves the way for apoptosis by inactivating NF-kB, a naturally occurring substance that regulates antiapoptotic proteins.
In “20 Years Younger,” exercise physiologist Bob Greene and nutrition specialist Diane L. McKay discuss some of the edible seaweeds that contain high levels of fucoidan. Kombu, popular throughout Japan but particularly in Okinawa, is a mild-tasting seaweed that is the primary ingredient in a broth called dashi. In addition to fucoidan, kombu is rich in magnesium, a mineral that is essential to optimal health. Hijiki, also known as hiziki, is rich in fucoidan, magnesium and potassium and is used fresh as a salad ingredient in Japan and other parts of the Far East. If you’ve enjoyed miso soup, you’ve already eaten wakame, a green vegetable that’s typically found floating in the soup. Also rich in manganese, wakame has high levels of sodium so limit your intake to avoid sharply boosting your sodium consumption. Limu moui, an edible seaweed popular in Polynesia, particularly Tonga, is also high in fucoidan. Most of these seaweeds can be found in Asian food stores, often in dried form.
A team of Russian researchers at Vladivostok’s Pacific Institute of Bioorganic Chemistry found that several species of marine invertebrates, some of which are edible, contain high levels of fucoidan. These creatures include sea anemones, sea cucumbers, sea snails and slugs, segmented marine worms, coonstripe shrimp, hermit crabs, snow crabs, whelks and a wide array of mollusks. Researchers published their findings in the March 2003 issue of "Biochemistry."