Nutrition from the Sea: Why You Need to Eat More Seaweed

by | Updated: March 28th, 2019 | Read time: 5 minutes

Sea vegetables are not the unfamiliar ingredients they once were. Sushi rolls can now be found in supermarket coolers, and seaweed salads grace many a mainstream restaurant menu. But even if you haven’t been sampling Asian food lately, you might want to reconsider how often you’re adventuring into kelp noodles salad or paleo sushi rolls. Not only are these greens from the sea a delicious addition to your diet, they’re also packed with nutrition your body craves.

Seaweed Under Water with a Couple Fish Indicate the Rich Nutrition & Benefits of the Sea Vegetables |

The benefits of seaweed

Edible seaweeds are considered supernutrients, because they provide trace elements that may be lacking from the typical Western diet, which is often nutrient-depleted in part due to overworked cropland. Many people also have a tendency to indulge in less-than-ideal dietary habits, favoring fatty or sugary foods over fruits and vegetables.

“Seaweeds are the most mineralized of any foods you can eat,” says Ryan Drum, PhD, a biomedical herbalist who has been harvesting, eating and studying seaweed since the 1960s. According to Drum, eating a mere ounce of seaweed a week can provide crucial minerals and a healthy dose of vitamins C, E and B complex, plus beta-carotene and a reliable source of dietary iodine.

“Maintaining adequate iodine levels in the body is necessary to maintain a healthy thyroid and to protect against radioactive iodine exposure,” says Drum. And although iodine deficiency is rare in the United States, seaweed is a foolproof source of iodine for people who prefer sea salt to iodized table salt.

Seaweed is also a good source of magnesium, folate, calcium and vitamin K – and it is extremely sustainable to harvest. Folks looking to incorporate anti-inflammatory foods may also want to reach for seaweed due to its high antioxidant capacity and omega-3 content. Lastly, seaweed serves as a wonderful prebiotic food. Prebiotics are crucial in maintaining gut health and feeding the probiotics that help make your gut flora thrive.

The good news is you don’t have to be a sushi fan to reap the benefits of seaweed. These days it’s pretty easy to find an array of ocean plants. Common varieties include wakame, nori, kelp, kombu, dulse, chlorella and spirulina, to name a few.

The different types of seaweed

Dulse – Dulse is a potassium powerhouse. It’s wonderful as a dried snack. In powdered form, it can be sprinkled on salads and grains. You can even try baking dulse into bread or layering it on sandwiches.

Kelp – It’s a brown algae usually dried and added to dishes during cooking. Kelp can also be made into noodles. This type of seaweed delivers a dose of folate as well as iodine. Try sprinkling the powdered form of sea kelp on grains, popcorn or vegetables. Kelp can also be added to smoothies or homemade energy bars for a sneaky dose of minerals.

Nori – Probably the most popular seaweed for eating, nori delivers protein, fiber and vitamin C, and it has a sweet, meaty flavor. You likely know nori sheets mostly for wrapping sushi. But you can add this seaweed to soups, re-wet nori seaweed for salads or use the sheets as a wrap for lunch and breakfast foods.

Wakame & kombu – These sea vegetables are two of the large brown “kelps.” Wakame is known for its calcium and magnesium content, and kombu is packed with iodine. Kombu is sometimes used as a seasoning in dried or canned beans, because it contains an enzyme that aids digestion. While both can be eaten dried, they’re often best soaked and sauced, cooked with grains and legumes, or tossed into soups or seaweed salads.

Chlorella – This is a green, freshwater algae that is often sold as a powdered supplement or tablets. Chlorella powder is best mixed into smoothies or yogurt, but it can also be added to baked goods for a boost of hidden nutrients, including vitamin A and iron.

Carrageenan – Many people are surprised to find out carrageenan is a type of seaweed. It’s used as a thickening agent in foods such as almond milk and ice cream. It has stirred up controversy, leaving may to wonder if carrageenan is safe to consume. The science is still inconclusive. But if you’re trying to avoid all kinds of additives, keep an eye out for carrageenan on food labels.

Spirulina – Spirulina is a type of seaweed grown in fresh warm waters. The blue-green algae is technically considered cyanobacteria instead of a true algae due to its chemical structure. Still, spirulina provides phytonutrients, along with minerals and protein. Spirulina is also a source of chlorophyll – the component that gives plants their green pigment. The rich green hue makes spirulina powder a great natural food coloring for desserts or Easter eggs.

The potential dangers of seaweed

Though the benefits of seaweed are strong, there are a couple of potential drawbacks to these algae you’ll want to know before diving in.

Since seaweed is high in iodine, folks with thyroid issues should be careful they don’t overdo seaweed consumption. Too much iodine can actually cause elevated TSH levels and decrease T3 and T4, which can be harmful for those with a pre-existing thyroid condition. Generally, enjoying seaweed as a condiment (1-2 tablespoons) on occasion (2-3 times per week) will not exceed the 3-milligram dietary limit of iodine for those with existing thyroid problems.

Certain types of seaweed can also cause digestive issues in those who are prone to gastrointestinal troubles. Carrageenan specifically, can cause inflammation in the gut. Be careful of toxic metals in seaweed, as well. The levels depend where the seaweed is harvested. For example, a seaweed called hijiki, is known to contain arsenic. There are many seaweed manufacturers that pay for a third-party verification that tests for heavy metals, so be sure to do your research before consuming any seaweed product.

The easiest ways to eat more seaweed

Because of its many forms and flavors, seaweed can be substituted for a number of foods. Try any one of these seaweed swaps to up your intake:

  • Instead of tortillas, wrap your tacos in nori sheets.
  • Replace spinach for wakame to make a mineral-packed salad
  • Chomp on seaweed chips in lieu of the popular potato
  • Season your salad dressing with dulse instead of salt
  • Nix the wheat noodle and try low-calorie, low-carb kelp noodles