Seaweed or Marine Macroalgae is a genus of plants that can grow on beaches or in the depths of the ocean along with rock or other hard substrates.
These seaweeds were classified before the 19th century on the basis of the morphological traits, pigmentation, regulation of photosynthetic membranes, and chemical characteristics of photosynthetic storage products. But after half of the 19th century, they were divided into four different groups on the basis of color.
Seaweeds based on the Rhodophyta phylum are classified as RED ALGAE, including about 6000 species. Second, seaweeds based on the Cyanophyta phylum were classified as BLUE-GREEN ALGEA, which includes about 1500 species.
Third, seaweeds based on the Chlorophyta phylum are classified as GREEN ALGAE (classes: Pryophytophyceae, Chlorophyceae, Tocyclotophyceae, Prasinophyceae, & Ulvophyceae), which includes about 1200 species.
Finally, seaweeds are classified as BROWN ALGAE based on the Ocrophyta phylum, which includes about 1750 species belonging to the biopsy family.
In fact, Seaweed found in the sea and around the world’s ocean is widely used in the manufacture of active medicines and cosmetics because they contain essential trace elements, minerals, proteins, and numerous medicinal benefits. Seaweed, classified as algae, is one of the most commonly consumed foods by humans.
In countries such as Korea, Japan, and China, seaweed has been utilized as a staple food in the daily diet since ancient times.
More so, they are currently consumed in various Asian countries (Vietnam, Singapore, Cambodia, Thailand, Brunei, Taiwan, China, Japan, Malaysia, and Korea) due to the importance of protein nutrition.
Fresh or dried seaweed is also eaten as a staple in Indonesia, Chile, South Africa, Scandinavia, South West England, the Philippines, Scotland, California, Belize, Ireland, Peru, Wales, and the Canadian Maritimes.
Although these are marine plants, their photosynthetic mechanism is similar to that of terrestrial plants. It’s simple cellular system, which converts sunlight into organic matter, receives water, CO2, and other nutrients in aquatic environments.
Marine Macroalgae is rich in vitamins, proteins, lipids, minerals, polysaccharides, and enzymes and is considered a nutritious supplement for the 21st century. Green algae, brown algae, and red algae contain the same amount of vitamins A, E, C, and niacin.
Table of Contents
Unknown Facts of Seaweed
Red algae contain more concentrated folic acid, folic, pantothenic acid, vitamin B12, and vitamin B1 than brown algae. Brown algae are high in organic iodine, which is the raw material in the manufacture of commercially available disinfectants or pesticides.
Seaweed is the equivalent to oats, which is high in carbohydrate and protein nutritional values, besides, red and green algae contain at least 2% to 4% of crude protein.
All 4 classifications of algae have high content of carbohydrates (important in biochemical structure), which is a nontoxic colloidal substance used as a mucilaginous material (gel-like structure).
The nutritional value of seaweed is affected by season, species, water temperature, and geographical area. The French government has recently recognized that Marine Macroalgae can be consumed by humans as vegetables and condiments.
Seaweed is an excellent natural source that meets consumer protection regulations, technical specifications, and industrial requirements. This marine plant is widely used not only for food but also in the manufacture of medicines and cosmetics.
In addition, high-fiber seaweed is used as fodder for livestock and as a chemical-free fertilizer for the soil. It is worth noting that the total value of algae production in a year is $ 6 billion, of which the total value of seaweed used for human consumption is $ 5 billion.
As the demand for seaweed has increased, various countries are now increasingly interested in cultivating it. Today, seaweed is being produced on all continents, with China becoming the largest producer, followed by Japan and Korea.
Alginate, carrageenan, and agar act as emulsifying and thickening agents. At the same time, brown and red Macroalgae, which provide hydrocolloids, are also widely utilized. 1 million tons of wet Seaweed produces approximately 55 000 tons of hydrocolloids (worth $ 600 million).
Common Types of Seaweed
Seaweed, the staple food of marine life, is found in certain colors, such as red, green, brown, and black. Currently used as a staple food in many parts of the world, this seaweed grows along rocky shores and in the deep sea. Today, countries such as Japan, Korea, and China are the largest producers of algae. These include a variety of macroalgae used in smoothies, soups, sushi rolls, salads, stews, and supplements. Here are the most important and common types of them.
Nori refers to the Japanese name of the red algae Pyropia, which includes P. tenera and P. yezoensis. These seaweeds have a unique taste, and are transformed into well-dried sheets. These algae are used as wrapping sheets in Japanese food such as onigiri or sushi rolls. These dry Nori algae are converted into sheets by the rack drying process, it absorbs moisture in the air and is easily decomposed. Therefore it is very important to focus on storing Nori seaweed sheets.
Sea lettuce is a type of green Nori Seaweed, but it looks like the lettuce leaves we eat in our daily diet. Widespread on the coasts of the world’s oceans, these Marine Macroalgae belong to the group of green algae, including the genus Ulva. All marine algae in the genus Ulva have the name Ulva Lactuca, in this, the Latin word Ulva means “Lettuce“. The species Ulva now include seaweeds that were initially classified under the genus Enteromorpha. Just like we utilize spinach, we can eat it with soups or raw with salads.
There are 30 different types of brown algae called Kelp, which form rows of elongated Laminariales. Although their appearance is similar to that of a normal plant, they are a Heterokont.
These algae, which were grown in the Miocene about 5 to 23 million years ago, grow as “Kelp Forests” in the shallow seas. Kelp, a term widely used in the 19th century, related to seaweeds, and sodium carbonate, also known as soda ash, is gained when burning dried kelp.
These plants can grow at temperatures of 6°C to 14°C and grow at a rate of half a meter per day, eventually reaching the height of 100 to 260 feet. Dry brown algae can usually be used as a gluten-free food instead of noodles.
The word “Kombu” is derived from the Japanese word Konbu, which is an edible Macroalgae belonging to the family Laminariaceae. Kombu, also known as the “King of Seaweeds”, is widely eaten by people living in East Asia. Kombu is called Dasima in Korean and Haidai in Chinese. Kombu, a type of kelp plant with a strong flavor of seaweed, is often used extensively in pickles or soups.
Arame, a sea oak plant, belongs to the Kelp genus of brown algae. These seaweeds, which are abundant in the temperate Pacific Ocean, are very popular in Japanese cuisine. These seasonal plants can grow up to about 1 meter in height, and fronds present in this plant are shed then new plants grow every year. Arame algae harvested manually or mechanically have a firm texture and a mild sweet taste. This seaweed is eaten in combination with various types of baked goods.
Wakame is an edible seaweed belonging to the genus Undaria pinnatifida. Although they have a subtle sweet taste they give a unique and strong taste when used for food. Wakame has been cultivated and used as a marine plant by Japanese farmers in Japan since the Nara period (AD 710 – AD 794). Fresh Wakame seaweed in the brown algae classification is commonly used to make salads, soups, and stews.
Rhodmenia palmata, a red algae (Rhodophyta) algae, is also known by various names such as Palmaria palmata, Dulse, Sea Lettuce flakes, Dilsk, Red Dulse, Dillisk. Dulse algae, which thrive on the northern shores of the Pacific and Atlantic Oceans, are a well-known snack consumed by the people.
Known as the Sol in Iceland, this marine plant has been used for centuries as the most important source of food for its enormous fiber. They are classified as red algae, have a very smooth texture, are brown in color, and appear elongated. Dulse seaweed, which has various nutritional values, is added to a variety of foods for flavor and is eaten as a snack.
Chlorella is a genus of single-celled green algae belonging to the genus Chlorophyta. This flagella-free seaweed is about 2 to 10 m in diameter and spherical in shape. Chlorella stores its photosynthetic pigments (green) in chloroplast into two groups, chlorophyll-A, and chlorophyll-B.
They thrive in conditions where freshwater, sunlight, and carbon dioxide are available and require only a small amount of minerals to reproduce. Green algae called Chlorella can be grown in freshwater so they are classified under edible seafood. Also, this freshwater algae can be used in powder form as a food supplement.
Agar, algae classified into red algae, has jelly-like properties, unlike other algae. Also known as agar-agar, they are a combination of small molecules called agaropectin and linear polysaccharide agarose.
This versatile compound, which can form a subsurface on the cell walls of certain types of algae, is expelled by boiling agar seaweed. These algae, which belong to the Rhodophyta phylum, are called Agarophytes. Agar is used as a raw material in desserts all over Asia.
They are also used as a solid molecule to maintain cultural media for microbiological work not only in Asia but in various countries around the world. Agar seaweed, which acts as an appetite suppressant, filtering agent, and laxative, is used in the preparation of fruit juices, ice cream, and desserts.
The word Carrageenan means “Small Rock” in the Irish language, a species of linear sulfate polysaccharide classified in red algae. They are widely used in the food industry because of their thickening, emulsifying, and stabilizing properties.
There are three main types of carrageenan: Kappa-carrageenan (one sulfate group per disaccharide), Iota-carrageenan (two sulfate group per disaccharide), and Lambda-carrageenan (three sulfate group per disaccharide).
Carrageenan seaweed is used in combination with protein foods such as milk and meat as it has a strong binding nature with proteins. The juice of this delicate seaweed has been used as a food additive since the 15th century. Carrageenan is the best vegetarian substitute instead of gelatin.
Health Benefits of Super Healthy & Nutritious Seaweed
Marine alga is a common ingredient in Asian cuisine, however, it is widely used by health-conscious Westerners. Macroalgae is the most important seafood vegetable for individuals who want to add extra minerals, vitamins, and fiber to their diet. Regular intake of healthy and nutritious edible Macroalgae will protect the body from various diseases and enhance health.
Not all saltwater and freshwater seaweed are edible, but some species are recognized as edible algae because they are high in minerals. Adding seaweed to the diet maintains proper digestive health, thyroid function, and weight loss. This section focuses on the benefits of Seaweed.
1. Rich in Several Nutrients
Seaweed has a higher value of nutrients than other foods, that is why people consider it as a nutritious sea vegetable. However, the nutrient content of these marine plants varies depending on the environment, water quality, and location. So each type of seaweed contains different amounts of nutrients.
In particular, since dry algae accumulate more nutrients than fresh algae, the body can get enough nutrients by consuming 8 grams of seaweed daily. Chlorella and Spirulina seaweed contain twice as much protein and all the essential amino acids the body needs than other seaweed.
Macroalgae is one of the best sources of vitamin B12 found naturally in eggs, milk, and meat. Seaweed is a natural marine plant rich in antioxidants that make it a perfect source of protein.
Consumption of seaweed, which contains a certain amount of sulfate polysaccharides and plant compounds that can contribute to the health benefits, can have beneficial effects.
In general, adding seaweed to the diet is a simple way to provide vitamins and minerals without adding calories. A study on marine drugs found that seaweed contains fiber, carbohydrates, minerals, proteins, and polyunsaturated fatty acids.
In particular, research in the Journal of Applied Phycology has shown that Macroalgae contains vitamin A, vitamin B, vitamin C, vitamin E, iodine, iron, and high levels of antioxidants. Their antioxidants help protect the body from inflammation at the cellular level and oxidative stress.
The nutritional value found in 100 grams of seaweed is revealed here.
- Calories – 45
- Carbs – 10 grams
- Protein – 2 grams
- Fat – 1 gram
- Folate – 45% to 50% of the RDI
- Magnesium – 27% to 180% of the RDI
- Calcium – 15% to 60% of the RDI
- Fiber – 14% to 35% of the RDI
- Manganese – 10% to 70% of the RDI
- Sodium – 10% to 70% of the RDI
- Vitamin K – 7% to 80% of the RDI
- Copper – 6% to 15% of the RDI
- Iron – 3% to 20% of the RDI
- Iodine – 1% to 65% of the RDI
- Potassium – 1% to 45% of the RDI
- Contains certain amounts of fatty acids called omega-3 & omega-6
- Has significant amounts of Vitamins A, C, E, B
- Phosphorus and Choline nutrients are also present in small amounts
2. Contains Protective Antioxidants
Free radicals are unstable substances that appear in the body, attacking the immune system and causing a variety of adverse effects. Excessive production of free radicals in the body can be the underlying cause of various diseases including type 2 diabetes and heart disease.
More so, these intensify the process of damaging the cells. Antioxidants are substances that can fight these free radicals and reduce their effects and keep the body safe. Seaweed contains antioxidant vitamins A, C, and E which effectively prevent risk factors such as heart disease.
In addition, they contain numerous plant compounds, such as carotenoids and flavonoids, all of which have been shown to protect cells from the effects of free radicals.
Brown algae such as Wakame are high in a specific carotenoid called fucoxanthin. Foucault has 13.5 times more antioxidant capacity than vitamin E, and studies have shown that this carotenoid is more effective at protecting cell membranes than vitamin A.
Energy is enhanced by consuming Macroalgae along with fatty foods. Different seaweeds are high in a variety of plant compounds that have strong antioxidant effects, thereby protecting the body from the negative impacts.
3. Boosts Thyroid Function
The thyroid gland secretes hormones that help in energy production, reproduction, growth, and cellular repair. Thyroid is one of the most important glands that greatly regulate the body’s metabolic functions, besides, iodine (the most important source) produces these thyroid hormones.
Iodine deficiency in the body causes a loss of thyroid hormone secretion, which can lead to hypothyroidism. Hypothyroidism can cause a lack of energy, swelling of the neck, dry skin, fatigue, tingling in the arms and legs, weight changes, depression, and forgetfulness. At the same time, high iodine production can lead to Hyperthyroidism.
Marine algae have the ability to absorb 150 mg concentrated iodine from seawater per day, which is sufficient according to the Recommended Dietary Intake system called RDI.
As already mentioned, the iodine content of seaweed varies depending on its type and the environment in which it is grown.
According to a study by the Journal of Food and Drug Analysis, species such as Kombu, Wakame, and Dulse are high in iodine, but species such as Spirulina and Kelp are moderate in iodine. So make sure you’re consuming seaweed with adequate iodine which can help to prevent hypothyroidism and hyperthyroidism.
Seaweed has approximately 11-1,989% RDI, Kelp type seaweed is the best source of iodine, and 3.5 grams of the dry Kelp sheet has 59 times RDI. In addition, seaweed contains the amino acid called Tyrosine, which in combination with iodine stimulates the activity of the thyroid gland by forming two major hormones.
4. Promotes Gut Health
Beneficial bacteria in the gut play a vital role in breaking down complex foods, facilitating digestion, and promoting overall health. Various studies have proven that there are far more bacterial cells (good and bad) in the body than human cells.
The imbalance between the two types of bacteria, the “good” and the “bad”, is a risk factor for various physical ailments and infections. Marine algae provide excellent health for good bacteria which play an enormous role in human health.
That is, dried seaweed, which is the best source of fiber, contains approximately 25% to 75% fiber, making it an excellent food for intestinal bacteria. Ingestion of fiber content promotes the growth of good bacteria in the gut and improves intestinal health.
Macroalgae is higher in fiber than most nutritious vegetables and fruits recommended by doctors. Adding small amounts of seaweed to the diet can protect against diarrhea, abdominal pain, constipation, and digestive disorders.
Prebiotics, another type of indigestible fiber, is another great food for good bacteria. The complex polysaccharide is known as fucoidans in brown algae such as Agar and Carrageenan act as excellent prebiotics.
Besides, certain amounts of sulfate polysaccharides found in seaweed effectively support the growth of good intestinal bacteria, and studies show that they also increase the production of SCFA (short-chain fatty acids).
Short-chain fatty acids form butyrate, but their impact on the gut is inhibited by the anti-bacterial and anti-inflammatory properties of seaweed. Animal studies have shown that implementing seaweed intake improves the number of good bacteria and effectively reduces the number of harmful bacteria.
5. Effectively Stabilize Blood Sugar
When blood sugar levels become out of balance, a major health problem called diabetes occurs. Research shows that at least 642 million people worldwide are expected to have type 1 or type 2 diabetes by 2040.
Fiber has the ability to effectively control the amount of insulin and glucose in the blood, so it is possible to control blood sugar levels by consuming high-fiber foods. Interestingly, seaweed contains enough fiber to help lower blood sugar effectively without an increase in calories.
There is also evidence that some of the compounds found in seaweed can control type 2 diabetes. An antioxidant called fucoxanthin gives brown algae a unique color and subtle properties. This fucoxanthin helps to stabilize blood sugar levels and reduce insulin resistance.
The rapid absorption of corps in the diet is also the main reason for the increase in blood sugar levels, and the rate at which corps are absorbed is reduced by consuming Macroalgae. Continued consumption of seaweed deals with diabetes risk factors including high-fat accumulation, insulin sensitivity, and inflammation.
60 Japanese people were divided into three groups and they were given seaweed oil daily. The oil given to the first group contained 0 mg of fucoxanthin, 1 mg for the 2nd group, and 2 mg for the 3rd group. Blood sugar levels were found to be lower in those who consumed 2 mg of fucoxanthin oil than in those who consumed 0 mg of fucoxanthin oil.
Patients with type 2 diabetes were given high doses of seaweed powder daily. At the end of the four-week study, participants’ sugar levels were proven to be at least 15-20%. In another study, participants were given a carp-rich diet, after 30 minutes they consumed seaweed juice.
It was found that those who ingested seaweed juice had an 8% increased insulin sensitivity than those who took a placebo. High insulin sensitivity is very helpful in controlling blood sugar levels very effectively.
In addition, dried Macroalgae contains a substance called alginate, which helps control post-meal blood sugar, and helps prevent the absorption of sugar into the bloodstream.
Seaweed powder was given as a supplement for 2 consecutive months to patients with type 2 diabetes. At the end of the study, their blood sugar level was 12% lower and hemoglobin A1C level was 1% lower. A 1% decrease in hemoglobin A1C lowers blood sugar by an average of 130 mg/dl. Overall, any form of Macroalgae can be of great benefit to blood sugar control.
6. Demotes the Risk of Heart Disease
Heart disease is one of the leading causes of death. High blood pressure, lung disorders, overweight, high cholesterol, and excessive blood clotting are important cardiac disorder factors. Some of the beneficial nutrients in seaweed improve heart health and help control risk factors.
Algaes are high in fiber and omega-3 fatty acids, which help to effectively reduce the amount of fat in the blood and keep it consistent at all times.
In particular, the soluble fiber in them binds with body salts or bile acids to reduce body fat. Due to this process, the total body fat can be reduced by about 18%.
In a study of high-fat rats, they were given a 10% dry Macroalgae. At the end of the eight-week study, the rats’ LDL cholesterol was reduced by 36%, total fat by 40%, and triglyceride levels by 31%.
Besides, seaweed contains carbohydrates called Fucans, which have the same ability to effectively control blood clotting as an anticoagulant drug. Numerous animal studies have shown that fucans and sulfate polysaccharides found in Macroalgae can prevent blood clots and high blood pressure.
Early animal studies have shown that peptides are an important protein structure in seaweed, which can greatly inhibit the risk factors that increase blood pressure. One group of type 2 diabetics was given Spirulina seaweed supplement and another group was given placebo daily.
At the end of this study, which lasted about 2 months, Spirulina ingested rats were shown a 24% reduction in triglyceride levels, a 166% decrease in total cholesterol, a 154% decrease in LDL cholesterol, and an increase in HDL cholesterol.
More so, different types of seaweed contain high levels of antioxidants, which can help support heart health.
7. Strengthens the Immune System
Seaweed has anti-allergic, anti-bacterial, anti-inflammatory, and anti-microbial properties that help protect the body from various infections. In addition, they contain high levels of antioxidants and plant compounds.
Research shows that the high concentration of compounds in Macroalgae can effectively prevent harmful cells from entering the body and fight viruses such as HIV and Herpes.
Researchers also stated that if HIV patients regularly ingest seaweed in the form of supplements, they can easily treat the impact caused by the HIV virus and it could be a best precautionary measure against the virus.
Besides, the two cited studies suggest that the positive impact provided by the Macroalgae can effectively reduce the symptoms of the herpes virus.
In a recent study of HIV-positive women, they were divided into two groups and given 5 g of Spirulina seaweed supplements for one group and placebo for the other.
At the end of the 12-week study, it’s demonstrated that up to 27% of HIV-related symptoms and side effects were decreased in women who took seaweed supplements compared to the placebo group.
Algae are used not only to treat the HIV virus but also as preventive medicine for various diseases and as a natural remedy that does not cause side effects.
8. Reduces the Risk of Cancer
Researchers have found that seaweed is very effective in controlling a hormone called estrogen, which helps in sexual and reproductive development in women. Excessive production of estrogen can cause breast cancer in women, and researchers recommend consuming natural seaweed to prevent it.
Besides, adding seaweed to the diet as a staple food will prevent the entry of certain types of cancer cells and their effects. In addition, fibers greatly help prevent the development of colon cancer.
In that sense, Macroalgae contains a lot of soluble fiber which effectively inhibits the growth and spread of colon cancer and also helps in intestinal health.
Research on brown algae such as Kelp, Wakame, and Kombu has shown that some of the compounds found in them are active in preventing the spread of cancer cells. Excessive seaweed intake may increase the risk of certain types of cancer, including thyroid cancer.
Therefore, taking a certain amount or recommended amount of seaweed directly or in the form of a supplement will protect the body from the dangers. The direct effects of seaweed have been shown to be successful in some cancer patients.
9. Aids Weight Loss
Consuming seaweed, the best source of fiber, in your daily diet can greatly reduce obesity and bad LDL cholesterol. Seaweed has the ability to dissolve body fat without increasing calories, and it helps reduce the amount of appetite that is often triggered by acid secretion.
That is, the fiber in it provides the feel of fulfillness to the stomach so that the stomach doesn’t send signals of hunger to the brain for long periods of time. A substance called fucoxanthin in seaweed helps to produce leptin hormones released by fat cells, thereby preventing fat accumulation.
Several animal studies have shown that seaweed, which has anti-obesity effects, lowers LDL cholesterol in the body and significantly raises HDL cholesterol. The study was performed on mice to demonstrate the anti-obesity effects of seafood.
In it, the rats were divided into two groups, and one group was given control diets and the other group was given seaweed containing fucoxanthin. In conclusion, the expression of a metabolizing protein in seaweed ingested rats was demonstrated to be increased.
In particular, fucoxanthin significantly lowers blood sugar levels, making them an indirect factor in weight loss. Furthermore, sPS Fucoidan present in the seaweed prevents the formation and accumulation of fat by enhancing fat breakdown.
Although marine algaes are low in calories, they are rich in the amino acid called glutamate, which is thought to give savory, umami flavor.
Therefore, foods made with Macroalgae may help to induce weight loss by providing a quality alternative to high-calorie snacks.
10. Other Potential Benefits
By lowering high blood pressure, obesity, heart disease, and cholesterol, the dried seaweed can reduce the risk of developing metabolic syndrome. Seaweeds are highly recommended as food and snack for all ages due to their potential capabilities.
All types of edible algae contain a wide variety of preservatives, compounds, and acids that prevent skin damage caused by UV rays. It is recommended to take it in daily diet as seaweed works naturally in dealing with various skin problems like premature skin aging, sunspots, sunburns, wrinkles, blemishes, pigmentation.
High levels of antioxidants found in Macroalgae can cure rheumatism, arthritis, osteoporosis, and joint pain. In particular, their anti-inflammatory effects reduce the risk of developing bone and inflammatory diseases.