Be A Weed Eater: Seaweed is a Sustainable Food that Offers a Boatload of Nutrition

Whether it’s floated past you at the Jersey shore or hugged the shrimp in your Godzilla sushi roll, chances are you’ve encountered seaweed in some shape or form. A popular staple in countries like Japan, Korea and China, it’s been welcomed to the West by way of those seeking a healthier diet. What’s more, its benefits extend beyond the plate as a sustainable crop, proving there’s more to seaweed than what’s beneath the surface.

“Interest in seaweed as food appears to be related to an interest in both health-conscious eating and environmentally-sustainable eating,” says Colette Feehan, marine biologist and associate professor of biology at Montclair State University. “The latter relates to the potential ecosystem services provided by seaweed farms, in that they are a lower carbon food compared to many land-based foods,” she says, noting that seaweed farming does not require outsourced water, fertilizers, or land use like most agricultural crops.

“In fact, seaweed can actually remove excess nutrient pollution (nitrogen and phosphorus) released by humans that might otherwise cause deleterious algal blooms, which can produce toxins that can cause mass mortality in marine animals, or enter human foods causing illness,” says Feehan.

Seaweed grows simply by absorbing the nutrients surrounding it.

INTEREST IN SEAWEED AS FOOD APPEARS TO BE RELATED TO AN INTEREST IN BOTH HEALTH-CONSCIOUS EATING AND ENVIRONMENTALLY-SUSTAINABLE EATING.

“Sunlight and existing nutrients in the ocean produce its biomass,” she says. “It is therefore a highly renewable resource, provided that sufficient nutrients and sunlight are available.”

Feehan explains that, though there are many different types of seaweed consumed globally, three dominate in diets: Saccharina latissima (kombu, sugar kelp), Undaria pinnatifida (wakame, another type of kelp), and Porphyrapyropia (nori, a red algae).

“Most seaweeds are processed for direct human consumption or as hydrocolloids (i.e., carrageenan, alginate, and agar) that are used as stabilizing, thickening, suspending, and gelling agents in food, cosmetics, and pharmaceuticals,” she says.

While seaweed can be highly nutritious, Feehan notes that many experts have indicated the need to monitor seaweed for metal toxicity. “Where heavy metals are present in the ocean environment, seaweed can absorb and concentrate toxins such as cadmium and inorganic arsenic,” she says. “For this reason, seaweed farms can also be used to remediate heavy metal pollution in polluted waters,” says Feehan, adding that in those cases, the seaweed cannot be used for human consumption, but could be used to make bioplastics or biofuels, further reducing carbon emissions.

The benefits of eating seaweed are numerous, as are the types to choose from. “There are many types of edible seaweed available, ranging from green seaweed (chlorophytes), which includes sea lettuce and umibudo; brown seaweed (phaeophytes) like kombu, wake, arame, and hijiki; and red seaweed (rhodophytes), that includes nori and dulse,” says Dr. Fariha Amer Saleem, MD, of Franklin Family Practice, a division of Robert Wood Johnson Barnabas Health in Somerset.

The texture of each is unique, ranging from light and crispy when dried (like nori, often used in sushi rolls) to firm and chewy (like kombu, found in miso soup). The flavor is earthy with variations of salty minerality—and that’s for good reason, as it’s a good source of minerals and vitamins.

“Seaweed is good source of vitamin A, which benefits vision and eye health; calcium, which supports healthy bones; zinc, which supports the immune system; and magnesium, which helps regulate blood pressure,” says Saleem. “It’s also rich in vitamin B12, in which many people are deficient. B12 supports healthy nerve cells and can prevent against megaloblastic anemia, which causes fatigue, weakness, and neuropathy.”

What’s more, seaweed can benefit thyroid health.

“Seaweed contains iodine, which promotes thyroid function,” Saleem says, explaining that the thyroid is a gland located at the base of the neck that produces hormones and controls metabolism. “Your thyroid gland takes iodine in small amounts and uses it to create thyroid hormone,” she says, adding that those who have hyperthyroidism should be careful when eating seaweed because it increases thyroid function. Individuals with an overactive thyroid produce too much hormone, which affects the body’s metabolism and can cause anxiety, rapid heart rate, mood swings, and more. Other foods that contain iodine include fish, shellfish, beef, liver, chicken, infant formula, eggs, dairy and iodized salt.

While too much salt can negatively impact our health, not all salt is created equally.

“The salt in seaweed is better than table salt because it contains less sodium chloride and more potassium salts, which can actually help lower blood pressure,” Saleem says. “Seaweed flakes (like dulse) are a good salt substitute because of the additional nutrients they provide.”

So the next time you’re looking to add a twist to a dish, take the plunge and give seaweed a try—a nutritious food of sustainable sustenance.

MORE ON SEAWEED SUSTAINABILITY
 

“Seaweed farming could reduce the pressure on natural seaweed forests by replacing wild harvesting. Yet, most of the seaweed consumed by humans is already farmed (97 percent of the 30 million tons of seaweed used by humans in 2018 was farmed, according to an article published in 2020 by the Food and Agricultural Organization of the United Nations). Given that the decline of habitat-forming seaweed is a worldwide concern (due primarily to climate change), further reducing wild harvest should be beneficial to ocean conservation.” —Dr. Colette Feehan, marine biologist and associate professor of biology at Montclair State University

There is interest in developing a seaweed farming industry in New Jersey. A recent New Jersey Department of Agriculture report called to “develop a mechanism to enable pilot programs that advance aquaculture of native macroalgal candidate species in state waters” (NJDA 2021).

Incorporating seaweed into your diet

Start by purchasing seaweed flakes and sprinkling them on rice, vegetables, meat, or other savory dishes, almost like a salt substitute. Once you get used to the taste, try incorporating them on a larger scale. —Dr. Fariha Amer Saleem, MD, of Franklin Family Practice, a division of Robert Wood Johnson Barnabas Health in Somerset

SCAVENGED VERSUS STORE-BOUGHT SEAWEED?

In terms of consuming scavenged seaweeds, Dr. Colette Feehan of Montclair State University urges to err on the side of caution in concern to possible microbiological hazards, noting a 2002 report by the FAO and WHO mentioning the health risks of consuming uncooked seaweed that was not handled properly.

SOME POPULAR GROCERY STORE SEAWEED BRANDS OF GOOD REPUTE:

• Eden Foods
• Maine Coast Sea Vegetables
• gimMe
• NORA
• Annie Chun’s
• ONE Organic
• Ocean’s Halo