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10 of Nori's Nutritional Benefits: Are You Seaweed Savvy?

Homemade vegan sushi, nori benefits

Jump to Recipe (sushi bowl)

What are the nutritional benefits of nori and other seaweed? Nori is red seaweed rich in protein, fibre, vitamins A and C, calcium, iron, and potassium. Nori is also a good source of iodine and can provide up to 50% of the daily recommended intake in a single sheet.

Nori's Nutritional Benefits

What are the specific health benefits of eating nori? Here are some potential benefits of consuming nori:

  1. Boost Your Nutrient Intake: Nori is like a multivitamin in a snack! It's full of goodness like vitamins A, C, E, and K and minerals like iodine and iron that your body loves.

  2. Support Muscle Health: If you want to keep your muscles happy, nori has a good amount of protein. 

  3. Aid in Weight Loss: Trying to lose weight or keep it off? Nori is low in calories, so you can munch away without worry.

  4. Enhance Thyroid Function: Your thyroid is a little gland with a big job, managing your metabolism. Nori's iodine content gives it a helping hand.

  5. Protect Against Free Radicals: nori helps your body fight off the free radicals with its antioxidant powers.

  6. Improve Digestion: Nori keeps things moving smoothly in your digestive tract, thanks to its fibre. 

  7. Promote Heart Health: Love your heart by eating nori, which has omega-3 fatty acids to keep your heart beating.

  8. Lower Cholesterol Levels: Nori might help keep your cholesterol levels in check, making it a friend to your heart and arteries.

  9. Strengthen Your Immune System: With all the vitamins and minerals packed in nori, it's like a shield for your immune system, helping you fight germs.

  10. Support Blood Sugar Control: For those keeping an eye on blood sugar, nori could be a helpful ally by improving how your body uses insulin.

The Nutritional Benefits of Seaweed in Your Diet

The nutritional components of seaweed make it an attractive ingredient in many seaweed food products and recipes. Seaweed, including varieties like nori, brown seaweed, and green seaweed, are full of nutrition. They are an excellent source of essential amino acids, dietary fibre, and iodine.

Iodine deficiency can lead to various health issues, particularly affecting the thyroid gland. These marine plants are beneficial for maintaining thyroid function due to their iodine content. Iodine supports the production of thyroid hormones.

Eating edible seaweed can also help regulate blood sugar levels. It can improve insulin sensitivity, making it a good choice for diets aiming to manage metabolic syndrome. The fibre content in seaweed, especially soluble fibre, promotes gastrointestinal tract health. and can contribute to a feeling of fullness.

Is Dried Seaweed High in Iron?

Health Benefits of Seaweed Infographic

Yes, dried seaweed has iron. Seaweed is high in iron. A single nori sheet typically weighs around 3 grams and contains approximately 0.5 to 2 milligrams of iron.

For context, the Recommended Dietary Allowance (RDA) for iron varies by age and gender. For example, adult men and postmenopausal women need about 8 mg daily, whereas premenopausal women need about 18 mg daily.

The exact amount of iron in seaweed can vary based on the origin and processing methods. Nori, including nori sheets, is a good plant-based source of iron, especially useful for those following vegetarian or vegan diets. Although dried seaweed such as nori is high in iron, you may want to diversify your iron sources to ensure you meet your requirements.

What type of iron does seaweed have?

Non-heme iron is found in plants, including the iron in dried seaweed. It's not absorbed as well as heme iron from animals, but eating foods high in vitamin C can help absorption.

Non-heme iron helps prevent anemia, boosts the immune system, and helps brain development. It's a good choice for people cutting back on meat for health or ethical reasons. Plant-based iron sources also have lots of antioxidants and fibre.

Benefits of the iron in seaweed and dried seaweed:

  1. Prevents Anemia

  2. Boosts Energy Levels

  3. Supports Immune Function

  4. Enhances Cognitive Function

  5. Promotes Healthy Pregnancy

  6. Improves Skin Health

  7. Regulates Body Temperature

Nutritional Profile for 5 Grams of Dried Nori

Is nori seaweed good for you? Yes, it packs a nutritional punch! Here is an estimate of the nutritional profile of five grams of dried nori, roughly two sheets of nori wrap. Remember this is not exact as the growing conditions and the way the nori is processed will impact the end nutritional profile. This table is here to give you a rough guideline.

Table for 5 Grams on Dried Nori


Estimated Amount


9-15 kcal


1-2 g


1 g


0.3-1 g



Vitamin A

140-450 micrograms (20-50% of RDA)

Vitamin B12

1.2-2.4 micrograms (50-100% of RDA)

Vitamin K

36-90 micrograms (26-361% of the RDI of 90 micrograms for adult females, 21-270% of the RDI of 120 micrograms for adult males).


80-215 micrograms (53-143% of the RDI of 150 micrograms for adults)


0.6 mg


Contains phycocyanins and chlorophyll

Sushi rice bowls topped with dried nori and sushi rolls should stay on the menu. Dried nori and nori sheets also have magnesium, calcium and potassium. As you can see dried nori is high in some of its nutritional content, so you would not want to eat large amounts. That is why I have created the table for such a small amount, to illustrate that a little goes a long way.


What is seaweed?

Seaweed is an aquatic plant that grows in marine or saltwater bodies. Seaweed is also referred to as macroalgae. The size of seaweed can range from tiny single-celled organisms to large complex multicellular species that can grow up to 60 metres (200 feet) in length.

Seaweed is essential to a healthy marine ecosystem as it provides food and habitats for marine life. People use seaweed as food, for medicine and in industries such as fertilisers, biofuels, and cosmetics.

What are the health benefits of eating seaweed?

Nori is the most commonly eaten seaweed, but all the edible varieties have some benefits. Here are some potential benefits of seaweed, including nori:

  1. Good source of iodine, important for thyroid health and metabolism

  2. High in vitamins and minerals, such as vitamins A, C, E, K, and B vitamins, calcium, iron, magnesium, and potassium

  3. Contains antioxidants that protect cells from damage

  4. May support heart health by reducing blood pressure, inflammation, and improving cholesterol levels

  5. May have anti-cancer properties due to high content of compounds such as fucoidan and fucoxanthin

  6. Contains prebiotic fibre that support beneficial gut bacteria and may improve gut health.

How and Where Does Nori Grow?

When cultivating nori, it doesn't thrive under direct sunlight. Direct sunlight can be too harsh for nori, as it can cause overheating and inhibit its growth. Instead, nori needs some light and cool temperatures. 

Nori farms are usually on the coast. Seaweed can grow there in cool, underwater conditions. These conditions are crucial in producing high-quality and nutritious seaweed. 

A key strategy in nori cultivation is to position it in deeper or partially shaded waters. This placement is strategic. It serves as a protective barrier, shielding the nori from the harmful full sunlight. It also ensures its optimal growth.

Marine and saltwater are used interchangeably to describe bodies of water with high salt levels. Marine bodies connect to the ocean, such as seas and estuaries. Tides influence them, and their salinity levels change depending on rainfall and evaporation.

Marine water bodies tend to have more saline, whereas saltwater bodies tend to have lower levels that depend on location and the surrounding environment.

Saltwater is a broader term used to describe water with dissolved salts. Saltwater bodies can include marine environments and inland bodies of water such as salt lakes and estuaries where fresh and saltwater mix (brackish estuaries).

Some types of seaweed have adapted to grow in freshwater bodies such as streams, rivers, and lakes. These forms are usually less complex in structure than marine seaweeds.

What is Organic Seaweed?

Organic seaweed is grown and harvested according to organic standards. These standards aim to ensure sustainability and environmental friendliness.

Is organic seaweed better for you than non-organic seaweed? This depends on the nutritional content, environmental impact, and exposure to contaminants.

What are the different types of seaweed?

Seaweed can be categorised based on its pigmentation (green, brown, or red), morphology (growth structure), and habitat.

Some common examples of edible seaweed:

  • Kelp

  • Nori

  • Dulse

  • Sea lettuce

  • Wakame

  • Spirulina

What are the different culinary uses of seaweed?

Kelp is a type of brown algae that is commonly used in Asian cuisine. It is often used in soups, salads, and sushi dishes.

Nori is a red algae commonly used in Japanese cuisine, particularly for making sushi rolls. It is usually toasted and has a slightly sweet, nutty flavour.

Dulse is a red algae commonly used in European cuisine, particularly in Ireland and Scotland. It has a chewy texture and a salty, smoky flavour and is often used as a snack or added to soups and stews.

Sea lettuce is green algae commonly used in salads and soups. It has a delicate, slightly sweet flavour and a crisp texture.

What are the nutritional benefits of other seaweed?

Kelp is a brown seaweed rich in iodine, calcium, iron, magnesium, and vitamin K. It is a good source of antioxidants. It contains a fibre called algin, which has been shown to help lower cholesterol levels. Kelp is low in calories and fat.

Dulse is red seaweed rich in protein, fibre, and minerals such as iron, potassium, and magnesium. It is a good source of vitamins B6 and B12 and contains antioxidants that can help protect against cellular damage.

Sea lettuce is a type of green seaweed. It is low in calories and fat and is a good source of vitamins A and C and minerals such as calcium, potassium, and iron. It contains a type of fibre called Ivan, shown to have prebiotic properties that can promote digestive health.

Wakame is a brown seaweed rich in vitamins and minerals, including vitamin C, calcium, and iron. It is a good source of fucoxanthin, a type of carotenoid that has been shown to have anti-inflammatory and anti-obesity effects.

Spirulina is a type of blue-green algae consumed as a dietary supplement. It is a complete protein source rich in vitamins, minerals, and antioxidants. Spirulina has been shown to reduce inflammation and improve immune function.

Can seaweed be used as a substitute for other ingredients?

Salt: Seaweed is naturally salty so it can be used as a substitute for salt in some recipes. For example, you can crumble dried seaweed onto popcorn or use it to season roasted vegetables.

Fish sauce: Many Southeast Asian recipes use fish sauce; seaweed has a similar flavour and can be used as a replacement when mixed with soy sauce or rice vinegar.

Gelatin: Agar agar, a type of seaweed-derived product, can be used as a substitute for gelatin in recipes that require a gelling agent to make jellies, puddings, and other desserts.

Pasta: Kelp noodles can be used as a substitute for traditional wheat-based pasta. Kelp noodles are gluten-free and low in calories.

Meat: Some types of seaweed, such as dulse or nori, have a meaty flavour and texture that can be used to replace meat. You can use dried seaweed as a topping for salads or sandwiches or add flavour and texture to soups and stews.

How can I incorporate seaweed into my diet?

  1. Salads

  2. Soups and stews

  3. Sushi

  4. Snacks

  5. Smoothies

  6. Seasoning

Sushi Bowl Recipe

Ingredients (Per Person):

½ cup cooked rice (e.g. sushi rice)

½ avocado, sliced

½ small cucumber sliced

½ small carrot, grated

¼ cup cooked edamame

½ a nori sheet, cut into small pieces or strips

1 tablespoon soy sauce

1 tablespoon sushi seasoning (rice vinegar and sugar)


  1. In a small bowl, mix the wet ingredients to make the dressing

  2. Add the sushi rice to a bowl

  3. Arrange the avocado, cucumber, carrot, and edamame on top of the sushi rice

  4. Sprinkle the torn nori sheet on top of the vegetables

  5. Drizzle the dressing over the top of the sushi bowls.

  6. Serve and enjoy!

You can add other ingredients to your sushi bowl, such as tofu, pickled ginger, or sesame seeds.

Seaweed Safety

How often should I eat seaweed? recommends eating sea vegetables, such as seaweed or sushi sheets, at least once a week. Sea vegetables are a good source of several vital nutrients, including iodine, iron, and vitamin K, and can be a healthy addition to many diets. However, it's essential to remember that some types of seaweed, such as kelp, can contain very high levels of iodine and should be consumed in moderation.

Is all seaweed safe to eat?

It's important to note that not all types of seaweed are edible, and some can be toxic. It's best to purchase seaweed from reputable sources and be familiar with the specific type before consuming it.

Are there any potential health risks associated with eating seaweed?

Seaweed is considered safe when consumed in moderation and purchased from reputable sources. However, there are some things to consider.

Iodine: Some types of seaweed, particularly kelp, contain very high levels of iodine. Over an extended period, consuming large amounts of iodine can lead to thyroid problems, particularly in people who are already iodine-deficient or have underlying thyroid conditions.

Heavy metals and other contaminants: Seaweed can absorb heavy metals and other contaminants from the water it grows, particularly in areas with high pollution levels. It's crucial to choose seaweed products tested for contaminants and be mindful of potential contamination.

Contamination risks may come from areas that are industrialised, close to agricultural areas or suffered from oil spills. Look for seaweed products that have been certified organic, non-GMO, and/or tested for heavy metals and other contaminants.

Carrageenan: Some types of seaweed, particularly red seaweed, contain carrageenan, a stabiliser and thickener in many processed foods. Some studies have suggested that carrageenan may cause inflammation and digestive problems in some people, although the evidence is mixed.

Allergic reactions: Some people may be allergic to seaweed or sensitive to certain types of seaweed. Symptoms of an allergic reaction can include hives, itching, swelling, and difficulty breathing.

China is one of the largest producers of seaweed in the world, and the country has strict regulations on food safety and quality control. However, there have been occasional reports of seaweed contamination in China due to pollution and other environmental factors.

Some seaweed products from Asia may be contaminated with high levels of arsenic. Arsenic is a naturally occurring element that can be present in some seaweed species, and high levels of arsenic can be toxic. It's important to choose seaweed products that have been tested for arsenic levels and to consume them in moderation to avoid excessive exposure.

Does seaweed interact with medication?

Seaweed can interact with certain medications. It is essential to talk to your healthcare provider before consuming large amounts of seaweed.

Here are a few examples of medications that may be affected by seaweed:

  • Blood thinners: Seaweed contains high levels of vitamin K, which can interfere with the action of blood-thinning medications such as warfarin.

  • Thyroid medications: Seaweed contains high levels of iodine, which can affect the function of the thyroid gland.

  • Diabetes medications: Some types of seaweed, such as kelp, may affect blood sugar levels and potentially interfere with diabetes medications.

What should I look for when buying seaweed?

Organic and sustainable: Choose seaweed that is certified organic and sustainably harvested to ensure that it is free from harmful chemicals and harvested in an environmentally responsible manner.

Brand reputation: Choose a reputable brand that is known for producing high-quality seaweed.

Country of origin: Check where the seaweed is sourced from and research any potential issues with pollution or contamination in that area.

Quality and freshness: Look for seaweed that is fresh and of good quality. Check the expiration date and packaging to ensure that the seaweed is not expired or damaged.

How should I store dried seaweed?

Dry seaweed should be stored in an airtight container or a resealable bag in a cool, dry place away from sunlight. Good storage is essential to keep the seaweed fresh and prevent it from getting stale or developing moisture, which can lead to mould growth.

How is seaweed harvested?

Seaweed is harvested depending on the species of seaweed and its intended use.

  1. Wild harvesting: Some seaweed species, such as kelp, can be harvested by hand or using specialised equipment. Harvesters may wade into the water to manually cut the seaweed or use boats with specialised blades or rakes to harvest more significant quantities.

  2. Aquaculture: Many seaweed species are grown through aquaculture, which involves cultivating seaweed in controlled environments, such as tanks or offshore farms. Aquaculture can allow for more efficient and sustainable harvesting of seaweed.

  3. Mechanical harvesting: Some seaweed species, such as carrageenan-producing seaweeds, can be harvested using mechanical methods, such as cutting or suction harvesting.

What are the environmental benefits of seaweed farming?

There are some potential environmental benefits to seaweed harvesting, particularly when it is done sustainably.

Carbon sequestration: Seaweed is known to absorb and store large amounts of carbon dioxide (CO2) from the atmosphere, known as carbon sequestration. When seaweed is harvested and processed, the stored carbon can be removed from the environment and potentially used to offset carbon emissions in other sectors.

Nutrient removal: Seaweed can absorb excess nutrients, such as nitrogen and phosphorus, from seawater. This can help reduce nutrient pollution impacts on marine ecosystems, such as harmful algal blooms and oxygen depletion.

Sustainable food production: Seaweed is a sustainable food source that requires minimal inputs, such as freshwater and fertiliser, to grow. Seaweed cultivation and harvesting can also provide economic opportunities for coastal communities and support local food systems.

However, seaweed harvesting can also have environmental impacts if not done sustainably, such as overharvesting and damage to sensitive marine ecosystems. Seaweed harvesters and producers must use sustainable practices and work to minimise these impacts.

Is seaweed farming sustainable?

Seaweed harvesting, particularly wild harvesting, can have environmental impacts if not done sustainably. Overharvesting can lead to declines in seaweed populations, which can, in turn, affect marine ecosystems and the livelihoods of those who depend on seaweed harvesting.

Are there any regulations or guidelines for harvesting seaweed?

There are regulations and guidelines for seaweed harvesting in many countries. These regulations are intended to promote sustainable and environmental harvesting. Specific regulations and guidelines can vary depending on the location and the species.

Some common examples of regulations and guidelines for seaweed harvesting may include the following:

  • Quotas or limits on the amount of seaweed that can be harvested in a given area or period.

  • Restrictions on the use of specific harvesting methods or equipment that can damage marine ecosystems.

  • Requirements for permits or licenses to harvest seaweed, which may involve environmental assessments or consultations with local communities.

  • Monitoring programs to track changes in seaweed populations and ensure that harvesting levels remain sustainable.

  • Protocols for minimising environmental impacts and protecting sensitive habitats or species.

Seaweed harvesters must know and comply with these regulations and guidelines to ensure their sustainable practices do not negatively impact the marine environment.

What are the challenges of large-scale seaweed cultivation?

  • Site selection: Seaweed cultivation requires specific environmental conditions, such as suitable water temperature, salinity, and nutrient levels.

  • Infrastructure: Large-scale seaweed cultivation requires significant infrastructure, such as floating rafts, lines, and anchors.

  • Harvesting and processing: specialised equipment and can be labour-intensive.

  • Environmental impacts: Potential impacts include the release of nutrients and organic matter into the water, which can lead to eutrophication (over-enrichment) and harmful algal blooms, and the displacement of native species.

  • Market demand: While demand for seaweed products is increasing, the market is still relatively small and unpredictable.


Seaweed is an aquatic plant that can be found in marine or saltwater bodies and is essential to a healthy marine ecosystem. Seaweed is not only used as a food source but also in many other industries.

There are various types of seaweed, each with its own unique taste and nutritional benefits. Seaweed has health benefits, including being a good source of iodine, vitamins, and minerals, having antioxidants. Seaweed can be used as a substitute and is a versatile ingredient that can be used in salads, soups, sushi, snacks, and smoothies.

I hope you enjoyed this post. If you did, please share and thank you for reading.

For more on iodine read Best Sources of Vegan Iodine


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