Everything You Need To Know About Sea Vegetables

In a time when taking care of your health and immune system is more important than ever, there's one superfood you may be neglecting: Sea veggies. Sure, you've eaten those bits of seaweed in your miso soup, or wrapped around your sushi roll.

However, there is actually a wide variety of green, brown, and red seaweed or edible marine algae that fall into the sea vegetables category. And they are bursting with nutrients, some of which you just can't get from land vegetables.  

"Sea vegetables are a great addition to a healthy diet, right now and always," says registered dietitian Abby Cannon, J.D., R.D., CDN. But where do you start when it comes to this variety of veggies? Can you get them in your grocery store, or is there a sea vegetables supplement?

Experts have all the information you need to know about sea vegetables, varieties, benefits, and how to eat them.

There is considerable diversity in the edible seaweed family. The many available varieties come with different nutrition profiles and uses. The red algae—nori—might be the most familiar because it's typically used as sushi wrap or garnish. However, as seaweed becomes more mainstream, seaweed snacks, oils, seasonings, and even jerky are popping up in stores. 

You can find it raw, pickled, dried, powdered, and encapsulated. Chefs are becoming more adventurous by incorporating these veggies into everything from soup to ice cream. And if chomping on something that tastes like the sea just isn't for you, then you can forgo the taste and texture altogether by stirring the powdered form into smoothies or soups.

There are nearly 30 varieties of this large brown algae, known colloquially as "seaweed." This is the version of sea vegetable you are most likely to feel clinging to your legs while in the ocean. But you've probably also encountered kelp in your day-to-day while firmly on land; it's found in thousands of products. 

Algin, a versatile component in kelp, is an ingredient in toothpaste, shampoo, pharmaceuticals, and even ice cream. A rich source of nutrients like iodine, vitamin K, vitamin A, vitamin B-12, iron, magnesium, and lots of calcium (more than kale), kelp comes in both powder and capsule supplements, as well as raw and dried. There's even kelp jerky!

This briny seaweed is often sold in thin, dry sheets, either plain or toasted, and is what you usually find holding your sushi roll together. This is a great seaweed for the pantry because it lasts a very long time and can add instant umami (savoriness due to the amino acid, glutamate) to any dish. 

Get creative with it! Try your hand at making your own sushi, or crumble it up and use it in salad dressings, make nori-crusted steak, sprinkle it over popcorn, or use it in ramen. The list goes on and on. 

A type of blue-green algae, spirulina is a single-celled cyanobacteria that has been referred to as the most nutrient-rich food on the planet. Originally used by the Aztecs, it was resurrected by NASA to feed astronauts1 in space. 

Phycocyanin is the main active component that contributes to the algae's antioxidant2 properties.* Typically found in powder or tablet form, a single tablespoon is considered an incredible source of high-quality protein made up of every essential amino acid, as well as an array of vitamins, minerals, and electrolytes. 

Full of the same range of nutrients as other sea vegetables, dulse resembles red, leafy lettuce. But you probably won't find dulse raw. It's usually dried immediately after harvesting and sold as whole-leaf, flakes, powder, or in seasoning mixes. 

Next time you feel like a BLT, try pan-frying some whole-leaf dulse instead and see if you can tell the difference between it and bacon!

A brown seaweed, wakame is another popular one and is traditionally used in cold salads or as a topping on tofu, soup, sushi, or rice. 

Usually sold in dry form, it can be rehydrated by soaking it in water for a few minutes. This also helps remove some of the excess salt. Then toss it into your favorite salad and let the nutrients course through you. 

This freshwater algae is another powerhouse food. You will only find it as a supplement because its hard cell wall prevents it from being digested3 in its natural form. In addition to the numerous health benefits it shares with other sea vegetables, chlorella has also been shown to also absorb heavy metals4 in the body, aiding in detoxification.*

When it's cold and dreary outside, break out the kombu and the stockpot. This seaweed is used in dashi, a traditional Japanese stock. Use kombu alone or with dried bonito flakes for miso soup or as a seasoning liquid in other dishes. Better yet, combine with beans or other hard-to-digest vegetables like Brussels sprouts or cabbage. Kombo has enzymes that break down gas-producing raffinose sugars found in many legumes and vegetables. 

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All sea veggies tout numerous health benefits. They are rich sources of vitamins, minerals, fiber, protein, and fatty acids. What's more, scientists are showing the vast reach of their therapeutic properties, zeroing in on specific compounds that possibly improve heart health, fight disease, aid in weight loss, and balance blood sugar, to name just a few.* 

Unfortunately, we are regularly exposed to heavy metals from the products we use, pollution in our air, the food we consume (hello, high-mercury tuna), and even the fillings in our teeth. 

Heavy metals accumulate in our bodies and can leave us feeling run down and awful all around. But algae such as spirulina and chlorella5 help support the body's detoxification process.* In animal studies, these algae were able to reduce heavy metal levels, such as cadmium and lead.* 

Iodine is critical for thyroid health; without enough, you run the risk of hypothyroidism, which can cause a host of issues, including weight gain, fatigue, and goiter. It can cause complications during pregnancy, affect brain and bone development, and even cause pregnancy loss.

About a third of the world's population6 doesn't get the recommended dietary intake (RDI) for iodine of 150 mcg per day, and pregnant women7 are most at risk for being deficient. Luckily, seaweed8 is an excellent dietary source of this essential mineral, with kombu having the highest content followed by wakame and nori.* 

Excess free radicals cause cell destruction9, DNA damage, and are thought to contribute to many adverse health conditions. Antioxidants prevent this damage by scavenging free radicals.* The term itself can refer to a wide range of substances, including specific vitamins (A, C, E, and beta-carotene are the most common), flavonoids, and carotenoids, among many others. 

Sea veggies are chock-full of antioxidants and are the subject of numerous studies10 for their health benefits11.* 

Seaweed gives your gut some love. It's got more fiber than most fruits and vegetables, between 25 and 75% by dry weight12, which helps with digestion and keeps things moving.* And it's full of prebiotics, which feed the good bacteria in your gut and curbs the harmful ones.* It might even protect against H. pylori13, bacteria that can cause stomach ulcers, although these studies have yet to be carried out in humans.* 

As an added bonus, Jess Cording, M.S., R.D., CDN says, "The fiber in seaweed helps bind to cholesterol and escort it out of the body.* Fiber also helps you stay full longer to keep hunger and mindless snacking in check."*

In case you weren't paying attention, sea veggies are brimming with vitamins and minerals.* Aside from the antioxidants mentioned above, you'll find iron, copper, manganese, folate, zinc, sodium, calcium, and magnesium. 

In fact, seaweed is higher in minerals like copper and iron than meat or spinach! Eight grams of dried dulse has quadruple the amount of iron as 100 grams of sirloin steak.

These fatty acids get a lot of attention in health news lately, and with good reason—they protect against a range of adverse health conditions, especially benefitting cardiovascular health.* 

We all know that we can find the all-important omega-3s14 in fatty fish, but the fish are getting them from their diet of sea algae10, and you should too! 

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So, how do you get your hands on these good-for-you veggies? One of the easiest ways to incorporate sea veggies into your day is to add a powdered form—such as mbg's organic veggies+—to smoothies, a bowl of soup, or simply a glass of water. If you're using a veggie powder, Cannon also suggests using it as a topping for your favorite snacks, like popcorn.

If you're able to find fresh or dried seaweed, experiment with it in dishes, until you learn your preferences. "Try a bunch out and see what you like," advises Cording. For example, if you don't like the strong taste of kombu, often used in soups, then give wakame's milder flavor a try in a seaweed salad. 

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Whether you are purchasing fresh, dried, or powdered, it is important to look for certified organic sea vegetables. Sea vegetables are naturally absorbent, so they can pick up contaminants and heavy metals15 from their surroundings.

Organic sea vegetables are grown in controlled aquacultures or wild harvested in protected waters to ensure quality and purity.

"Buy the best quality possible," Frank Lipman, M.D., functional medicine pioneer, advises. "As with land veggies, look for seaweed that’s minimally processed, dried without additives or preservatives, and harvested from clean waters."

As an added bonus: Organic vegetables have been shown to contain, on average, 20 to 40 percent more antioxidants 16than their conventionally grown counterparts.* In fact, one study found that just one week of eating organic, significantly impacted toxin levels in participants urine.* So, whenever you can, opt for organic.

According to Cording, you should shoot for at least 4-5 servings per week, although the serving size will depend on the variety and form (fresh, dried, etc.). "That could be a half-cup of cooked seaweed, dried dulse flakes, or a handful of chlorella tablets," she explains. 

However, algae supplementation and seaweed salads might not be for everyone. Individuals who have thyroid issues should be especially careful. Several studies have shown that very high consumption of seaweed can interfere with normal thyroid function; hyperthyroidism17 has been reported in individuals taking kelp supplements. "Talk to your doctor if you are on thyroid medication or need to be mindful of limiting iodine intake. You also need to be careful with seaweed supplements, because they may be more concentrated and provide higher amounts of certain minerals that can interact with certain medications or impair the absorption of other nutrients," cautions Cording.

Sea veggies are edible marine algae or seaweed that can be found in fresh, dehydrated, or powdered versions. They are a good source of vitamins, minerals, beneficial antioxidants, and omega-3 fatty acids and can help support the body's detoxification process.* For an easy-to-take form try supplementing with the powdered variety (here are our favorites!) or tablets, if you're feeling more adventurous you can experiment with cooking different varieties in salads, soups, and smoothies.