Seaweed Nutrition: Green Superfood, Health Benefits

Seaweed Nutrition Green Superfood, Health Benefits

What Is Seaweed?

Seaweed is a general nomenclature used for a number of species of algae and marine plants that breed in varied water bodies like rivers and oceans.

They grow in a wide range of sizes from minuscule to gigantic. Most of the seaweeds are medium-sized and are available in multiple colors like red, brown, and green.

They can be spotted ubiquitously on the seashores or coastlines.

Microscopic seaweed like phytoplankton grows hanging inside the water.

Bigger ones like giant kelp, which is one of the largest plants in the world, grow enormously and stand like an underwater tree with its roots at the foot of the sea.

Unlike a weed that grows liberally and can be harmful to the area it dwells in, it plays an extremely vital role for the marine life.

It serves as a foundation for the majority of the food chains and provides home to a number of marine creatures.

In addition to this, seaweed possesses anti-microbial and anti-inflammatory properties that have been trusted for providing health benefits to the humans from ancient times.

Health Benefits Of Seaweed


Seaweeds contain cancer-fighting agents that may prove useful in curing tumors and other cancer conditions like colon cancer and leukemia.

Brown seaweed such as kelp, wakame, and kombu contain glycoprotein and sulphated polysaccharides called fucoidans that possess immuno-stimulant, anti-viral, and anti-cancer properties.

Research studies on the effectiveness of dietary seaweed on breast cancer have shown promising results in reducing the production of cancer-promoting hormones, including estrogen.

And have the ability to inhibit the proliferation of malignant cancer cells.

Source of Iodine

Seaweed is a rich source of iodine, which it absorbs in ample amounts from the sea water. Iodine is a vital nutrient required for proper growth for all age groups.

It is essential for the normal regulation of thyroid function, which also involves the brain and pituitary gland.

The thyroid hormone also plays an essential role in the process of myelination of the central nervous system in newborns.

A deficiency of iodine in the body can result in abnormalities such as thyroid enlargement or goiter, hypothyroidism, and mental retardation.

Iodine is extremely crucial in pregnancy and breastfeeding for the normal development of the brain cells of the baby.

Deficiency during these periods or early childhood can lead to weak intellectual growth and abnormal development of the brain.

Digestive Health

Seaweed has a mild laxative effect and is quite useful in maintaining healthy digestion.

It aids in stimulating the release of digestive enzymes, supporting the absorption of nutrients, and facilitating the metabolism of fats. 

Studies have shown that polysaccharides exert prebiotic effects on the gut, which helps in normal functioning of beneficial stomach bacteria and shields the stomach wall against harmful bacteria.


Laboratory research has made it evident that seaweed possesses antioxidant and anti-coagulant properties.

Anti-coagulants, also known as blood thinners, prevent the formation of blood clots and decrease the threat of stroke, cardiac failure, and obstruction in the veins and arteries.

The polysaccharides called fucoidans.

Which are present in brown algae, such as Turbinaria ornate, kelp, and bladderwrack exert this beneficial effect.


Seaweed possesses the ability to detoxify and cleanse the body and facilitates the excretion of toxic waste.

The binding property of the natural absorbent, alginate, which is present in it, makes toxic materials, including heavy metals like lead, mercury.

And other pollutants indigestible and eliminated them from the body through bowel movements.

Brain Booster

The edible red seaweed Gracilariopsis chorda, also known as GCE, contains high levels of arachidonic acid.

This acid promotes the repair and growth of skeletal muscle tissue. 

Heart Health

The regular consumption of seaweed also improves cardiovascular conditions such as high blood pressure, dyslipidemia, oxidative stress, vascular inflammation, and hypercoagulability, among others.

How? Well, the high amounts of nutrients found in seaweed such as soluble fibers, peptides, phlorotannins, lipids and minerals accomplish this. 

What nutrients are in seaweed?

Seaweed offers varying levels of protein depending on type. Red seaweed has the most, with up to 50 grams of protein per 3.5 ounces of nori.

Seaweed is a rich source of several vitamins, including vitamin A (in the form of carotenoids), vitamin C, vitamin D, vitamin E, and B vitamins.

Like kale and some other leafy greens, seaweed also contains vitamin K, which plays a role in blood clotting.

People who take anti-clotting medications, such as warfarin, may need to observe certain precautions when consuming foods high in vitamin K. 

Seaweed is also a rich source of several minerals, including calcium, magnesium, potassium, copper, and iron.

Seaweed also has a high iodine content, especially the brown-algae varieties. While that generally isn’t a concern, it may make seaweed risky for people who have overactive or underactive thyroids.

If you have a thyroid condition for which a low-iodine diet is recommended, it’s a good idea to talk with your doctor first before consuming seaweed products.

Does seaweed contain omega-3s, like fish and shellfish do?

Yes. Despite being low in fat, many species of seaweed are rich in omega-3s: both the long chain EPA as well as the shorter chain alpha linolenic acid.

Some species also contain DHA, the other long-chain omega-3 commonly found in fish and shellfish.

Are there any risks from eating seaweed?

Seaweeds easily absorb and store whatever is in the environment, just like fish and shellfish.

This means that if the water where they grow is contaminated with substances such as arsenic, mercury, lead, cadmium, or other heavy metals. The seaweed will contain those substances as well. A paper published in 2013 in Archives of Environmental Contamination and Toxicology found high blood mercury levels among South Koreans who consumed a moderate or high amount of seaweed compared with low consumers.

They also had significantly higher levels of arsenic in their urine.

To reduce your chance of arsenic exposure, avoid hijiki seaweed. Which is most commonly used in Japanese food and has been shown to have the highest arsenic levels among seaweed. Instead favor red seaweed.

To be on the extra cautious side, eat seaweed at most three times a week, and try to vary types or brands.

Most U.S.-based companies that harvest seaweed regularly test their seaweed for arsenic and other heavy metals, as well as bacteria, PCBs, pesticides, and radiation. Two such companies are Rising Tide Sea Vegetables and Maine Coast Sea Vegetables.

Seaweed Salad Recipe

This recipe is incredibly nutritious and healthy. In the raw version I’ve replaced the sugar with stevia and the rice vinegar with lemon juice. Of course we use a non pasteurized soy sauce: tamari (read the label!)

This super foods salad is fantastically nutritious and tasty. And as a bonus it’s very quick and easy to prepare.


  • Seaweed of your choice (raw, unroasted)
  • Stevia
  • Raw sesame oil
  • Sesame seeds
  • Bragg aminos or tamari
  • Lemon juice



For the dressing. combine stevia, oil, soy and lemon juice. Mix with the seaweed. sprinkle sesame seeds on top.