The Versatility and Health Benefits of Seaweed

Top 6 Seaweed Benefits + How to Eat It


Although it may be most well-known as a staple ingredient in sushi, seaweed is a versatile and nutritious food that can be enjoyed in a number of different ways. In addition to bringing a briny crunch to your favorite dishes, it has also been associated with a long list of health benefits, ranging from lower cholesterol levels to better blood sugar control and beyond.

So is seaweed good for you? This article will take a closer look at the potential seaweed benefits and side effects, plus some simple ways to incorporate it into your diet.

Seaweed - Dr. Axe

What Is Seaweed?

The term “seaweed” is used to describe several different species of marine algae that grow in oceans and rivers. There are many different species and varieties of seaweed, but it can be generally classified by its color.

The most commonly consumed types include red, green and brown algae, all of which provide a host of algae benefits.

Seaweed plays a central role in the marine ecosystem. It provides shelter for marine life, provides food and nourishment to some species, and even helps remove carbon dioxide from the atmosphere.

Not only that, but it’s also considered a key ingredient in certain areas and can frequently be found in Chinese or Japanese cuisines.


There are many different types of edible seaweed available, each of which has a unique taste, texture and appearance. They can also each range quite a bit in size; some species are microscopic while other types — such as kelp — can grow to be several hundred feet in length.

Here are a few of the most common seaweed types to look for on your next shopping trip:

  • Hijiki seaweed
  • Wakame seaweed
  • Ogo seaweed
  • Nori seaweed
  • Kombu seaweed
  • Arame seaweed
  • Dulse seaweed
  • Spirulina


The seaweed nutrition profile can vary quite a bit based on the specific type and variety. However, it is generally low in calories but high in important nutrients like copper, riboflavin and thiamine.

For example, one tablespoon of dried spirulina contains the following nutrients:

  • 20 calories
  • 1.5 grams carbohydrates
  • 4 grams protein
  • 0.5 grams fat
  • 0.3 grams dietary fiber
  • 0.4 milligrams copper (21 percent DV)
  • 0.3 milligrams riboflavin (15 percent DV)
  • 0.2 milligrams thiamine (11 percent DV)
  • 2.0 milligrams iron (11 percent DV)
  • 0.1 milligrams manganese (7 percent DV)
  • 0.9 milligrams niacin (4 percent DV)

In addition to the nutrients above, the seaweed nutrition profile also contains some iodine, potassium and magnesium.

Related: Bladderwrack Benefits for Thyroid Health, Digestion & More


1. Promotes Digestive Health

Seaweed is a high-fiber food, an important nutrient that plays a central role in digestive health. Most notably, increasing your intake of fiber can help prevent constipation by adding bulk to the stool to ease its passage.

However, fiber has also been linked to several other gut-boosting benefits, including protection against acid reflux, stomach ulcers, diverticulitis and hemorrhoids.

Not only that, but seaweed also contains several specific compounds, such as sulfated polysaccharides, that can enhance the growth of the beneficial bacteria in your gut. The gut microbiome is involved in nearly every aspect of health, ranging from nutrient absorption to immune function, inflammation and more.

2. Fights Free Radical Damage

One of the top benefits of dried seaweed is its antioxidant content. Antioxidants are compounds that help neutralize harmful free radicals and protect against oxidative damage.

High-antioxidant foods may also help prevent chronic health conditions such as heart disease, cancer and diabetes.

Fucoxanthin, in particular, is a type of carotenoid found in brown seaweed that has been associated with a number of powerful health benefits. According to a study published in International Journal of Molecular Sciences, fucoxanthin may exhibit up to 13.5 times the free radical scavenging activity as vitamin E, another common antioxidant.

3. Enhances Weight Loss

Seaweed is low in calories but high in fiber, making it an awesome addition to a healthy weight loss diet. This is because fiber helps support satiety to keep you feeling full, which could potentially aid in weight loss.

Certain compounds found in this sea vegetable may also help promote weight loss, including fucoxanthin. Although current research is limited to animal models, some studies have found that fucoxanthin could increase the expression of mitochondrial uncoupling protein 1 (UCP1), which is a type of protein that regulates metabolism.

4. Lowers Cholesterol Levels

Cholesterol is a type of wax-like substance that is found throughout the body. Although your body needs cholesterol to function, high levels can build up in the arteries and contribute to heart disease.

Some research suggests that adding seaweed to your diet could help reduce cholesterol levels to protect against heart disease since it acts as a cholesterol-lowering food.

One animal model published in Journal of Medicinal Food, for instance, found that administering a small amount of seaweed to rats on a high-fat, high-cholesterol diet was able to reduce levels of bad LDL cholesterol by a whopping 49 percent. Not only that, but it also reduced levels of total cholesterol and triglycerides while increasing levels of good HDL cholesterol in the blood.

5. Supports Thyroid Health

Seaweed is a great source of several important nutrients, including some that can help support the health of your thyroid gland. Iodine, in particular, is used by the thyroid gland to synthesize hormones, which are involved in regulating metabolism, muscle function, heart rate, body temperature and digestion.

An iodine deficiency can cause symptoms like fatigue, impaired growth, hair loss, increased sensitivity to cold and swelling in the neck.

Additionally, seaweed also contains a hearty dose of tyrosine, which is an amino acid that also aids in the production of thyroid hormones to support better thyroid function, among other tyrosine benefits.

6. Stabilizes Blood Sugar

Several studies have found that specific compounds in seaweed, including fucoxanthin, could help promote better blood sugar control. For example, one study out of Japan showed that taking two milligrams of fucoxanthin daily for eight weeks led to significant improvements in levels of hemoglobin A1C, a marker used to measure long-term blood sugar levels.

Other research in animals has also found that alginates, which are a type of polysaccharide found in seaweed, could impact blood sugar and insulin levels following a high-carb meal, which could also lead to improved blood sugar control.

Risks and Side Effects

Despite the many potential seaweed benefits, there are a few side effects and risks that need to be taken into consideration as well.

Heavy metals and contaminants like lead and mercury can accumulate in it, which could build up in the tissues of the body and negatively impact the central nervous system.

Although studies show that these toxic metals are unlikely to pose a significant health concern to most healthy adults, it is still an issue as many countries have not yet established regulations on the maximum levels for these heavy metals.

Selecting organic seaweed whenever possible and keeping your consumption in moderation can help reduce your risk of exposure to harmful contaminants and heavy metals.

Additionally, seaweed is an iodine-rich food, which is an important micronutrient that plays a key role in thyroid function. Although your body does need iodine, however, getting too much can actually be harmful.

Consuming high levels of iodine can trigger a similar set of symptoms as an iodine deficiency, including swelling of the neck (goiter), hypothyroidism and alterations in thyroid hormone levels.

Cooking seaweed prior to consumption is a simple way to reduce the iodine content to avoid going overboard. Be sure to also enjoy it in moderation as part of a healthy, well-rounded diet to prevent negative side effects.

Related: What Is Samphire? Surprising Benefits and How to Cook It

How to Cook and Eat It (Plus Recipes)

With a bit of creativity, the potential seaweed uses and recipes are practically endless.

Most types of seaweed are sold dried and don’t require cooking. However, many varieties (apart from nori) should be soaked in a bowl of warm water until they become tender and soft.

Once it is soaked, it can be eaten as is or added to recipes like seaweed salad, sushi bowls or even seaweed soup. It also makes a great addition to stir-fries, sandwiches and rice dishes to add a quick burst of nutrients and flavor.

For an easy seaweed snack idea, try coating a few sheets of nori with sesame oil and your choice of spices. Then bake for 15–20 minutes, remove and let cool for a bit before chowing down on your delicious seaweed snacks.

Here are a few simple recipes for other interesting ways to use seaweed:

  • Veggie Nori Rolls
  • Toasted Seaweed Chips
  • Green Beastie Smoothie
  • Sweet and Salty Sesame Seaweed Bars
  • Easy Peppermint Bark


  • Seaweed is a type of edible marine algae that is rich in nutrients, such as iodine, copper, riboflavin and thiamine.
  • There are several different varieties available, each of which varies in taste, texture, size and appearance.
  • Most types can help improve digestive health, lower cholesterol levels, enhance weight loss, stabilize blood sugar levels, support thyroid function and protect against free radical damage.
  • In addition to being highly nutritious, it is also very versatile and can be incorporated into salads, sushi, soups and smoothies, along with many other different recipes.

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