Seaweed Benefits, Nutrition Facts, Side-effects, And More

Have you observed those green paper wraps on your favorite sushi rolls? These wraps are seaweed, also known as macroalgae. They are edible. The benefits of seaweed are many, and you can find it along the rocky shorelines of the sea. It is highly nutritious and is considered a superfood for its health benefits. Seaweed is also an important food source for marine life and is available in different colors like green, red, and brown. This article explores the nutrition profile of seaweed, types, health benefits, and possible adverse effects. Keep reading to know more.

Seaweed Varieties

Seaweed formed an important part of the diet for coastal people in ancient times. Today, more than 145 varieties are used around the world. Most of the edible seaweed varieties differ in color coming from different species. As per their coloring pigment, they are broadly classified as brown algae (Phaeophyceae), red algae (Rhodophyta), and green algae (Chlorophyta).

• Nori, or purple laver, is the common dark-colored seaweed used in sushi preparations. With its high protein and nutrient content, it is one of the most nutritious types of seaweed.
• Aonori, or green laver, commonly known as “sea lettuce” is widely cultivated in Japan.
• Dulse is a type of red algae with leathery fronds.
• Haidai (in China) and Kombu (in Japan) are other types of dried seaweed.
• Other edible seaweed varieties include winged kelp, sea grapes, Irish moss, hiziki, and mozuku.

Trivia

Edible seaweed is chiefly marine algae, while freshwater algae types are largely toxic. However, marine algae from the genus Lyngbya are lethal enough to cause seaweed dermatitis upon contact, and digestive poisoning even upon consuming fish that have fed on it.

While seaweeds grow in oceans all over the world, they’re most commonly used in Asian cuisines, in sushi, miso soup, salads, and stews.

Let’s have a look at the nutrition details below.

Seaweed Nutrition Facts

According to the USDA, 2 tablespoons (10g) of seaweed (wakame variety) provides us with the following nutrients (1).

• Calories: 4.5
• Fat: 0g
• Sodium: 87.2mg
• Carbohydrates: 0.9g
• Fiber: 0g
• Sugars: 0g
• Protein: 0.3g
• Magnesium: 10.7mg
• Calcium: 15mg
• Iron: 0.2mg

Wakame seaweed

benefits come from important nutrients, such as iodine, vitamin B12, vitamin D, iron, calcium, folate, and magnesium. It is not only rich in nutrition but also low in calories.

Going further, let’s explore the many health benefits of seaweed, the superfood.

Health Benefits Of Eating Seaweed

Seaweed contains unique plant compounds that might help prevent a number of diseases and promote good health.

• May Protect Against Asthma

Since asthma is an inflammatory disease closely related to diet and environmental factors, the dietary intake of omega-3 fatty acids and vitamins found in seaweed seems to help in lowering the development of asthma. Higher intakes of seaweed and seafood have been associated with lower risks of asthma. Research on similar lines found a 34% reduction in the prevalence of doctor-diagnosed asthma on the dietary intake of seaweeds. Though more research is warranted, introducing seaweed early in pregnancy and childhood appears to be beneficial in preventing asthma (2).

• May Reduce Risk Of Osteoporosis

Seaweed contains antioxidant compounds called fucoidans which are indicative of protecting the bone-building cells, osteoblasts (3). This may help prevent bone damage and osteoporosis. A seaweed diet is also enriched with calcium and vitamin K, two key nutrients for bone strength (4).

• May Promote Heart Health

Inflammation, high cholesterol, oxidative stress, and high blood pressure are all potential symptoms of cardiovascular health concerns. Seaweed is rich in soluble fiber, antioxidants, and vital minerals that help alleviate these concerns and improve your heart health (5). Soluble fiber is known to bind to and help remove bad cholesterol from the body (6). Seaweed, especially kombu and dulse, are rich sources of soluble fiber (7), (8). In one study, rats with high cholesterol were given a high-fat diet supplemented with 10% freeze-dried seaweed. The results showed 40% lower total cholesterol, 36% lower LDL cholesterol, and 31% lower triglyceride levels (9). Additionally, the potassium in seaweed can also help lower blood pressure (5).

• May Help Proper Thyroid Functioning

Seaweed is rich in iodine that supports the proper functioning of the thyroid gland. The thyroid gland relies on iodine to make hormones. Seaweed can absorb highly concentrated amounts of iodine from the ocean water (10).

Without enough iodine, your body suffers from a condition called hypothyroidism with symptoms like fatigue, sudden weight changes, and swelling of the neck over time (11). The recommended dietary intake (RDI) for iodine is 150 mcg per day (12). Just one teaspoon (3.5 grams) of dried kelp could contain 59 times the RDI (13). You can enjoy kelp benefits by adding it to your salads, soups, and stews for a nutrient boost.

The average iodine content of three other dried seaweed varieties is as below (13):

• Nori: 37 mcg per gram (25% of the RDI)
• Wakame: 139 mcg per gram (93% of the RDI)
• Kombu: 2523 mcg per gram (1,682% of the RDI)

Along with iodine, the amino acid called tyrosine found in seaweeds also helps the thyroid gland function properly (14).

• Rich In Antioxidants

In addition to containing the antioxidant vitamins A, C, and E, seaweed contains a wide variety of beneficial plant compounds like carotenoids and flavonoids. These are known to protect our body from the effects of toxic free radicals (15), (16).

Fucoxanthin, the main carotenoid found in brown algae such as wakame, has 13.5 times the antioxidant capacity of vitamin E (15). It has been shown to protect cell membranes better than vitamin A (17). Seaweed is rich in a few other plant compounds with antioxidative properties as well (18).

• May Help Improve Blood Sugar Levels

As per a study conducted on Japanese people, fucoxanthin, a carotenoid found in brown seaweed, might help improve blood sugar control (19). Participants were given a local seaweed oil containing either 0 mg, 1 mg, or 2 mg of fucoxanthin. Those who received 2 mg of fucoxanthin were reported to have improved blood sugar levels, compared to the group who had received 0 mg (19). The study also noted additional improvements in blood sugar levels in those who are genetically predisposed to insulin resistance usually associated with type-2 diabetes.

Additionally, the fiber alginate in seaweeds was found instrumental in preventing spikes of blood sugar levels in animals after being fed a high-sugar meal. Studies suggest that alginate may help reduce the absorption of sugar into the bloodstream (20), (21).

• Seaweed Might Help In Weight Loss

Seaweed varieties contain a good amount of fiber that helps you feel full and delay your hunger pangs, thereby making you eat less (22). A 5g serving of brown, red, or green seaweed has been found to contribute up to 14.28%, 10.64%, or 12.10% of dietary fiber intake, respectively (23). Seaweed is also known to have anti-obesity effects. As per a few animal studies, compounds like alginate and fucoxanthin found in seaweed might also have fat-reducing effects (24), (25). Although these studies’ results seem promising, further research on humans is warranted to establish the findings.

Going further, let’s see how you can include seaweed in your diet to reap its many benefits.

How To Include Seaweed In Your Diet

Seaweed can be used fresh or as dried flakes. Let’s explore the different ways you can add seaweed into your diet:

• Make onigiri from rice and dried seaweed nori wrappers.
• Add it to your soups and salads.
• Add kombu to cooked beans.
• Make different varieties of homemade sushi.
• Mix fresh arame and wakame with vinegar, sesame oil, scallions, and garlic for a seaweed salad.
• Make a vegan salad with chickpeas, vegan mayonnaise, celery, red onion, salt, pepper, and dulse flakes.
• Top meals with a mix of ground nori, kombu, dulse, salt, black pepper, and sesame seeds.
• Make a soup broth with dried kelp or kombu.

Rosa, an Anglo-swiss food blogger, details how she had a bad experience with kelp tablets in her childhood. Later in life, when she was gifted with a box of mixed seaweeds, she decided to try it. She went on to cook it like she did spinach and curated a new dish, Creamed seaweed with lemon. She wrote, “The garlic and shallots brought lots of flavor to that dish, the lemon took away some of the smelliness/fishiness of the seaweed and the cream added a little roundness to it all (i).” She further said, “I must say that my “Creamed Seaweed With Lemon” had a refined taste and was very enjoyable. Something I will definitely try again and again.”

Quick Tip

Seaweed is considered a close vegan substitute for fish in seafood dishes. Look for simple preparation methods for a plant-based and intensely flavorful umami experience.

Having said that, do you know when and how you can source seaweed? Let’s explore that in the next section.

Best Time To Consume Seaweed

Seaweeds meant for human consumption were usually collected fresh from the seashore or picked in the sea. They were harvested locally and eaten fresh within a short span of time.

Soon people realized that seaweeds can be dried, transported easily, and stored for a longer time in dried form. This makes them readily available all through the year. So in case, you can’t get fresh seaweed in your region, you can most likely get your hands on some variety of dried seaweed in a nearby Asian grocery store. Seaweed farming or cultivation is also being widely practiced all over the world to meet its rising demand and popularity.

Having said that, let’s have a look at some of the potential drawbacks of seaweed.

Side Effects And Drawbacks Of Seaweed

Eating fresh seaweed as such is considered safe for most people. While the plant offers many health benefits as seen above, there are a few things to keep in mind before having seaweed.

Seaweed is a natural source of vitamin K, which might interfere with the anticoagulant effects of blood-thinning medicines like Coumadin (warfarin) (26). If you take seaweed or foods high in vitamin K regularly you should inform your doctor to help determine the right dosage of such medication (27).

Depending on the source of seaweed, it might contain high levels of heavy metals like mercury, lead, cadmium, and arsenic. Alternating between the types of seaweed and limiting your intake frequency might help you reduce heavy metal exposure from seaweed (28).

Seaweed may also be high in sodium unless it is organic.

Now let’s look into how you should store seaweed and the safety precautions you can take.

Storage And Food Safety

• Fresh seaweed like other leafy greens should be washed and cleaned under running water before consumption or further preparation. It can then be used directly or stored in the fridge for later use.
• Packaged dried seaweed, once opened, should be kept sealed or stored in an airtight container. Look for the “use by” date mentioned on the package and preferably get branded products to avoid any heavy metal toxicity.

Frequently Asked Questions

Is seaweed healthy to eat every day?

Yes. Fresh and dried seaweeds have a good nutritional profile and may help boost your health in many ways. However, moderation is key.

Does seaweed have collagen?

No. Polysaccharides from seaweed, however, inhibit collagenase, a substance that degrades skin collagen and causes skin sagging (30).

Does seaweed produce oxygen?

Yes, seaweed does produce oxygen through photosynthesis. Like land plants, seaweed contains chlorophyll, which enables them to convert carbon dioxide and sunlight into oxygen and glucose. As a result, seaweed contributes to oxygen production in aquatic environments, playing a vital role in the balance of marine ecosystems.

Is seaweed good for hair growth?

Yes, in a study with depilated mice, seaweed extracts demonstrated positive effects on hair growth (31). This treatment resulted in better hair regrowth, larger follicles, and increased expression of growth factors, hinting at seaweed’s potential to address hair loss (alopecia).

Is seaweed a vegetable or seafood?

Seaweed is not a vegetable or seafood but a marine plant. It belongs to the algae family and is rich in nutrients. While it grows in the sea, it is distinct from seafood.

Discover the prominent benefits of seaweed in skincare as well as nutrition. Check out this video to unlock the secrets of this saline superfood and just enough reasons to include it in your diet plan.

Personal Experience: Source

(i) CREAMED SEAWEED WITH LEMON – ALGUES
https://rosas-yummy-yums.blogspot.com/2010/08/creamed-seaweed-with-lemon-algues.html

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