A vegetarian restaurant on the Mendocino coast has begun serving a six-course "sea vegetable dinner," featuring sea palm, nori, dulse and wakame -- different forms of seaweed.
Though they're not your typical fare in the U.S., fresh sea vegetables are eaten all over the world by those who live close to the source.
Asian cuisines feature the most seaweed, but it's also found on the menu in Scandinavia, Scotland and Peru. In Nova Scotia, they dine on sea parsley, or dulse; in northeast Siberia they eat kelp harvested from the Bering Sea.
It's a bit of a misnomer to call them vegetables -- seaweeds are algae, and most are not considered members of the plant kingdom. Nonetheless, the nutrients found in seaweeds rival those of their terrestrial counterparts.
Seaweeds thrive in a mineral-rich environment -- and absorb an impressive array of these nutrients, including calcium, iron, magnesium, copper, iodine and zinc. Sea vegetables also contain small amounts of fat with a healthful ratio of omega-6 to omega-3 fatty acids, particularly in the case of dulse. Seaweeds are also one of the few vegetable sources of vitamin B12 -- a boon for strict vegetarians who have difficulty taking in enough of it.
Because they're exposed every day to potentially damaging ultraviolet light, seaweeds also produce a host of antioxidants in the form of protective carotenoid pigments and the vitamins C and E.
One unusual pigment in seaweed -- fucoxanthin, a carotenoid found in kelp -- was found in a 2005 study to help reduce body fat in rodents. Researchers at Hokkaido University in Japan fed mice and rats a fucoxanthin-supplemented diet for four weeks, resulting in significant drops in body weight and body fat compared with control animals that were fed the same amount of chow but no supplement. The scientists determined that fucoxanthin leads to an increase in the production of a protein called UCP-1 in fat tissue, which causes the body to burn extra calories by generating heat.
Unlike land plants, which are rich in starch and cellulose, seaweeds store their carbohydrates as less-familiar polysaccharides -- carrageenan and agar (in red seaweed), alginate, laminarin and fucoidan (in the brown) and xylans and ulvans (in the green). As well as providing fiber, some of these polysaccharides may offer other benefits as well. Fucoidan has been particularly well-studied in cell culture and animals, and has been shown to have anti-tumor, anticoagulant, antiviral and anti-inflammatory properties.
Chances are you consume more seaweed compounds than you realize, even if sushi isn't part of your daily diet. Because of their water-holding properties, many of the unusual carbohydrates (particularly carrageenan, agar and alginate) are extracted from seaweeds and used to thicken a variety of foods, including soy milk, chocolate milk, ice cream, yogurt, soups, salad dressings and jellies. These natural thickeners can contribute soluble fiber to the diet.
If you're interested in adding more seaweed to your diet, Asian restaurants are probably your best place to find fresh and dried varieties. The familiar dark sushi wrappers are made from dried red algae, and dried seaweed flakes are used to season many dishes.
Fresh seaweeds vary in flavor and texture. Fronds of green wakame, a kelp, have a slightly sweet flavor and, not surprisingly, a slippery texture. Like sea palm, it's best tossed into soup or stir-fried with a bit of soy sauce and sesame oil, or served as a salad tossed with a vinaigrette dressing.
Cooked dulse -- often described as soft, chewy and briny -- is eaten in Iceland with just some butter. But given its strong, salty flavor, it might best be added in small amounts to soups and stews.
Dried seaweed sheets and flakes are fairly widely available, even at some of the large supermarket chains. Finding fresh seaweed at your local market might be a bit of a challenge, although several Japanese markets that I contacted do carry it. If you're not sure how the family will respond when they ask what's for dinner, you can just tell them, truthfully: "seafood."
Susan Bowerman is a registered dietitian and assistant director of the UCLA Center for Human Nutrition.
Want to learn more about seaweed and how to cook it? Watch two seaweed devotees talk about their favorite food at www.chow.com/stories /10675; try a recipe for seaweed sweets at blog.al.com/enjoy/2007/07/seaweed_can_do_more_than_wrap.html; bake seaweed bread and other delicacies at seagrant.gso.uri.edu/factsheets/seaweed; whip up a dulse soup at www.atlanticmariculture.com/recipes.html. Or check out recipes in 2007's "The New Seaweed Cookbook: A Complete Guide to Discovering the Deep Flavors of the Sea," by Crystal June Maderia.