THE NUTRITIONAL AND MEDICINAL VALUE OF SEAWEEDS

There are four seaweeds commonly used in Chinese medicine:

• Laminaria (kelp), a brown algae and Ecklonia (the more commonly used item), a green algae as sources of kunbu (Laminaria is sometimes called haidai, to distinguish it from Ecklonia or other sources)
  
  
• Sargassum, a brown algae, as the source of haizao
  
  
• Pyrphora, a red algae, as the source of zicai

These seaweeds will be discussed briefly in this article.

SEAWEED'S NUTRITIONAL VALUE (1)

Seaweed draws an extraordinary wealth of mineral elements from the sea that can account for up to 36% of its dry mass. The mineral macronutrients include sodium, calcium, magnesium, potassium, chlorine, sulfur and phosphorus; the micronutrients include iodine, iron, zinc, copper, selenium, molybdenum, fluoride, manganese, boron, nickel and cobalt.

Seaweed has such a large proportion of iodine compared to dietary minimum requirements, that it is primarily known as a source of this nutrient. The highest iodine content is found in brown algae, with dry kelp ranging from 1500-8000 ppm (parts per million) and dry rockweed (Fucus) from 500-1000 ppm. In most instances, red and green algae have lower contents, about 100-300 ppm in dried seaweeds, but remain high in comparison to any land plants. Daily adult requirements, currently recommended at 150 µg/day, could be covered by very small quantities of seaweed. Just one gram of dried brown algae provides from 500-8,000 µg of iodine and even the green and red algae (such as the purple nori that is used in Japanese cuisine) provides 100-300 µg in a single gram.

The amounts of seaweed ingested as food in Japan, or in supplements, is often considerably more than 1 gram a day. Studies show that the human body adapts readily to higher iodine intake, where the thyroid gland is the main tissue involved in use of iodine (it is a component of thyroid hormones). Huge portions of the world population get insufficient iodine because the land, plants, and animals that serve as common dietary sources are very low in iodine. In many countries, iodine is added to table salt to assure adequate levels are attained. However, some developing countries are still catching up and suffering from the effects of low iodine intake. China is has the largest population with a history of low iodine intake, followed by India.

Aside from iodine, seaweed is one of the richest plant sources of calcium, but its calcium content relative to dietary requirements pales in comparison to the iodine. The calcium content of seaweeds is typically about 4-7% of dry matter. At 7% calcium, one gram of dried seaweed provides 70 mg of calcium, compared to a daily dietary requirement of about 1,000 mg. Still, this is higher than a serving of most non-milk based foods.

Protein content in seaweed varies somewhat. It is low in brown algae at 5-11% of dry matter, but comparable in quantitative terms to legumes at 30-40% of dry matter in some species of red algae. Green algae, which are still not harvested much, also have a significant protein content, i.e., up to 20% of dry matter. Spirulina, a micro-alga, is well known for its very high content, i.e., 70% of dry matter.

Seaweed contains several vitamins. Red and brown algae are rich in carotenes (provitamin A) and are used, in fact, as a source of natural mixed carotenes for dietary supplements. The content ranges from 20-170 ppm. The vitamin C in red and brown algae is also notable, with contents ranging from 500-3000 ppm. Other vitamins are also present, including B₁₂, which is not found in most land plants.

Seaweed has very little fat, ranging from 1-5% of dry matter, although seaweed lipids have a higher proportion of essential fatty acids than land plants. Green algae, whose fatty acid make-up is the closest to higher plants, have a much higher oleic and alpha-linoleic acid content. Red algae have a high EPA content, a substance mostly found in animals, especially fish. Seaweed has a high fiber content, making up 32% to 50% of dry matter. The soluble fiber fraction accounts for 51-56% of total fibers in green (ulvans) and red algae (agars, carrageenans and xylans) and for 67-87% in brown algae (laminaria, fucus, and others). Soluble fibers are generally associated with having cholesterol-lowering and hypoglycemic effects.

Seaweeds: Ecklonia (upper left); Porphyra (middle left); Sargassum (lower left); Laminaria (right)

FOOD USES

Probably the most widely known seaweed used for food is Porphyra, which literally means purple (see sample leaf below), reflecting its color in nature. The Chinese name is zicai, which means purple vegetable. It is classified among the red algae, which have red to purple pigments. Upon processing to yield the food, which is known in Japan as nori, the red pigments are lost and the final product has a dark greenish color. Nori is used to wrap sushi and for making numerous snacks. The other common food item is the low cost but highly nutritious kelp (kunbu in Chinese; kombu in Japanese). Kombu is usually sold in 5-6-inch dried pieces and can be found in health food stores and Japanese groceries (see sample package below). It is also sold as kombu that cooks quickly, vinegared, shaved kombu that needs little or no cooking, boiled, soy sauce flavored kombu, lightly pickled kombu, and powdered kombu that can be sprinkled on food or used in drinks. Dried kombu needs to be simmered for at least 20 minutes to soften it and flavor the liquid. If used only for flavoring stock, the kombu itself is removed from the liquid at the end of cooking and discarded. A third seaweed widely used in Japan is known as wakame (from Undaria pinnatifida). See the Appendix for information about seaweed utilization in Japan.

MEDICINAL USES

Seaweeds have a salty taste that is an indication that the material can disperse phlegm accumulation, particularly as it forms soft masses, include goiter, the thyroid swelling that indicates severe iodine deficiency. Following are the descriptions of the seaweeds from Oriental Materia Medica (2):

Kunbu (Laminaria and Ecklonia)

• Essence and Flavor: Salty, Cold
  
  
  
• Channel Entered: Liver, Stomach, Kidney
  
  
  
• Actions: Softens hardness, disperses accumulation, resolves phlegm, cleanses heat
  
  
  
• Applications: Scrofula, goiter, tumor, edema, accumulation, testicular pain and swelling

Haizao (Sargassum)

• Essence and Flavor: Bitter, Salty, Cold
  
  
  
• Channel Entered: Liver, Stomach, Kidney
  
  
  
• Actions: Disperses accumulated phlegm, disperses goiter and tumor, delivers water, cleanses heat
  
  
  
• Applications: Scrofula, goiter, tumor, edema, testicular pain and swelling

Zicai (Porphyra)

• Essence and Flavor: Sweet, Salty, Cold
  
  
  
• Channel Entered: Lung
  
  
  
• Actions: Resolves phlegm, softens hardness, dispels heat, promotes diuresis
  
  
  
• Applications: Goiter, beriberi [leg swelling], edema, urinary infection, sore throat

The descriptions for kunbu and haizao are quite similar. Yang Yifan (3) wrote about the differences between these commonly used seaweeds:

Haizao and Kunbu are salty and cold, and enter the liver, lung, and kidney meridians. Both can clear heat, transform phlegm, soften hardness, and dissipate nodules. They can also promote urination and reduce edema. In clinical practice, they are often used together to treat nodules such as goiter and scrofula.

There are some differences between the two herbs. Haizao is stronger in transforming phlegm and dissipating nodules, and it is more suitable for treating goiter and scrofula. Kunbu is stronger in softening hardness and reducing congealed blood; it is more suitable for treating liver-spleen enlargement, liver cirrhosis, and tumors.

One of the best known formulas with the seaweeds is Haizao Yuhu Tang, or the Sargassum Decoction for the Jade Flask (4). This formula of 12 ingredients includes Sargassum, Ecklonia, and Laminaria. It was used to treat a condition of goiter which was so severe it made the throat look like a large flask. However, these seaweeds have been adopted into formulas for treating other soft swellings, including ovarian cysts, breast lumps, lymph node swellings, lipomas, and fat accumulation from simple obesity.

REFERENCES

1. Secretariat of the Pacific Community Coastal Fisheries Programme, Seaweed's nutritional value, Fisheries Information Newsletter #95, October-December 2000.
   
   
2. Hsu HY, et al., Oriental Materia Medica: A Concise Guide, 1986 Oriental Healing Arts Institute, Long Beach, CA.
   
   
3. Yang Yifang, Chinese Herbal Medicines: Comparisons and Characteristics, 2002 Churchill-Livingstone, London
   
   
4. Bensky D and Barolet R, Chinese Herbal Medicine: Formulas and Strategies, 1990 rev. ed., Eastland Press, Seattle, WA.

APPENDIX: JAPAN AND SEAWEED

Following is an outline report on Japanese utilization of seaweed and seaweed products, with data from 1998, except as noted, thanks to the Fisheries Information Newsletter (1).

• Japan is the world's largest seafood producer, importer and consumer. Annual seafood expenditures totaled 36,425 yen (~$300 U.S.) per capita.
  
  
• Total fresh seaweed production was 623,286 tons for all types of seaweed. But, this is far less than Japan uses for certain seaweeds, particularly those used for industrial processing of specialty seaweed products.
  
  
• Today, Japan is the leading importer of seaweed, while Korea is the premier exporter-with Japan as its main customer.
  
  
• Japanese imports stood at a total of 71,800 tons of fresh seaweed produce valued at over $150 million dollars. It consisted of 40,900 tons of Undaria (a seaweed that grows in the Pacific, from Korea to Japan to Australia) imported from China and Korea worth $65.3 million dollars, plus other varieties worth $38 million dollars.
  
  
• Exports of seaweed from Japan were 1214 tons of miscellaneous seaweed, i.e., processable raw seaweed, dried kombu and nori worth $12 million dollars, plus 59 million dried Porphyra sheets (as used for making sushi) worth $4.6 million dollars. The exports are mainly sold to the USA and Taiwan.
  
  
• There are at least 21 seaweed species used daily in food preparation in Japan. The Japanese consume an average of 4 kg per capita every year (~11 grams per day). There is also a large industry built around the three common colloid compounds derived from seaweed: agar, alginate, and carrageenan. These are used to provide thickening and texture to foods, and for other uses.
  
  
• The agar industry started in Japan over 400 years ago in mountainous regions where, in cold winters, agar would set into a gel. Japan now imports the raw material, the seaweeds Gracilaria and Gelidium, from Chile and South Africa, for a yearly output of 1000-1500 tons of agar in 1994.
  
  
• Alginate extraction in Japan is carried out using Ecklonia and Durvillea imported from Chile and South Africa. The alginate obtained is high-quality material and is used in specific biotech applications. The use of Laminaria spp. for kombu, moreover, has resulted in the import of another raw material so as to extract alginates. Overall production of alginate is about 1000-1500 tons per year (1994 figures).
  
  
• The carrageenan industry is mainly based on direct imports of seaweeds (1,718 tons in 1994). Carragenophytes are also imported from Southeast Asian aquafarms (yielding Eucheuma and Kappaphycus) and from wild stocks in North and South America and Europe (yielding Chondrus and Gigartina).

Seaweed Farming in Japan

Seaweed farming is highly developed in Japanese coastal areas. The main species grown there are Porphyra (nori), Laminaria (kombu) and Undaria (wakame). These alone have accounted for 98% of overall Japanese seaweed production since 1984. The balance is made up of minor traditional (Monostroma, Enteromorpha and Cladosiphon) or experimental (Meristotheca and Grateloupia) crops or wild stock harvests.

Nori

Nori is a traditional food used, for example, to make sushi, which has been a highly profitable crop over the past century. Since the reproduction cycle's summer phase was discovered by Dr Kathleen Drew-Baker, farming has become easier and more lucrative - so much so that no imports have occurred since 1976. Porphyra cultivation is the largest sub-industry in Japanese aquafarming, employing 16,800 workers. In 1998, output stood at 10,326 million nori sheets, i.e. equivalent to 396,615 tons of fresh produce.

Kombu

Kombu is the most widely sold seaweed in Japan. It is an "all-purpose" product although it is most commonly used for bean-curd soup with kombu.

Wild stock still accounts for a major share of output. Several species of the genus Laminaria are used in the Japanese food industry. Laminaria japonica takes the lion's share of kombu production with a raw-material tonnage of 141,875.

Wakame

Undaria pinnatifida cultivation is a relatively recent development in Japan and wakame is served as a luxury food on Japanese and Korean tables. It is highly sought after for bean-curd soup or salads. Raw-material production, standing at 73,508 tons, is unable to meet Japanese demand for wakame.

How to get Stronger Teeth & Gums?

Eat these power foods to strengthen your teeth and gums

You know that some foods are bad for your dental health - but did you know that some foods are actually good for it? "Eating specific foods can strengthen and naturally whiten teeth and kill toxic bacteria in your mouth," saysMelvin Pierson, D.D.S., spokesperson for the Academy of General Dentistry. So dig in and fight tooth decay the
natural way.

Rebuild enamel
Yogurt, cheese, and milk are good sources of calcium, which helps shore up tooth enamel and strengthen the bone around your teeth. By forming a temporary coating on your teeth, calcium also deflects natural acids in your mouth and helps prevent decay.

Boost gum health
Grapefruit aids in wound healing and was shown to decrease gum bleeding in a German study. In addition, it prevents the collagen network in your gums from breaking down and loosening around your teeth.Grapefruit's acid can, however, temporarily reduce the strength of your tooth enamel, so dentists recommend
waiting at least 30 minutes after eating grapefruit to brush your teeth. And grapefruit interacts with some
medicines, so check with your pharmacist if you plan to start eating it regularly.

Bust bacteria
Kiwis, oranges, limes, cranberries, and strawberries are rich with vitamin C, a powerful killer of
oral bacteria. Green tea contains catechins that kill bacteria in the mouth. Spicy foods such as wasabi have phytochemicals that inhibit the growth of germs.

Smell sweeter
Some herbs naturally freshen the breath you exhale. Mint and parsley kill bacteria in the mouth.
Plus, they contain monoterpenes, substances that move rapidly through the bloodstream to your lungs to counter the odor in your mouth.

Stop stains
Cauliflower, spinach, lettuce, and broccoli are all sources of minerals that create a protective film on teeth and help prevent red wine, cola, or coffee stains from penetrating the enamel. Strawberries have bleaching elements to brighten your smile, while hard, crunchy foods such as carrots, nuts, and seeds help slough off plaque.
Chewing raw veggies also stimulates saliva, which neutralizes acids and strengthens teeth using vitamins and minerals from the foods.

Do You Need Vitamin Supplements?

Even people with the best intentions sometimes fall short on their nutrient intake. For some people health supplement offers benefits that are both safe and effective. Health supplement may help when:

FOR WOMEN:

You're pregnant or trying to become pregnant.
During this time, you need more of certain nutrients, especially calcium, folate and iron. Folate is needed very early in pregnancy to help protect your baby against neural tube birth defects, such as incomplete closure of the spine (spina bifida). Iron helps prevent fatigue by helping you make the red blood cells necessary to deliver oxygen to you and your baby. Your doctor can recommend a dietary supplement. It's important to start taking a supplement before becoming pregnant.

You’re always on a diet.
If you're restricting your caloric intake significantly, there's a good chance that you're undernourished. Consider supplementing your diet with a general multivitamin with added calcium to ensure you're meeting your daily nutritional needs. Although vitamin supplementation isn't a substitute for healthy eating, it can serve a purpose in certain groups of people who don't get an adequate intake of fruits, vegetables, meat, or dairy based products. If you fit into one of these categories, ask your doctor if vitamin supplements would be right for you. In the meantime work on getting more vitamins and nutrients from your diet so you can stay healthy and strong.

You're a woman who has heavy menstrual bleeding. If you have heavy menstrual bleeding, you may need additional iron to replace the iron depleted by blood loss. Iron deficiency can lead to anemia, a condition in which blood is low in hemoglobin, the substance which carries oxygen to tissues. You're a postmenopausal woman. After menopause, women experience a sudden drop in estrogen levels, which increases bone loss. To keep bones strong and to decrease bone loss, you need calcium as well as vitamin D — the vitamin essential for absorbing calcium. Women who don't obtain enough calcium and vitamin D through foods could benefit from taking a calcium supplement with vitamin D.

FOR MEN & WOMEN:

You’re primarily a fast food eater.
If you eat on the run and frequent the notoriously unhealthy fast food restaurants, you may want to consider supplementing with a multivitamin. Many fast foods and convenience foods are notably lacking in nutritional value. A multivitamin is an inexpensive way for you to make sure you're meeting your daily requirements. Keep in mind that getting your nutrient requirements from supplements is not ideal since we don't know whether supplementation is as effective as getting your vitamins through food.

You have a medical condition that affects how your body absorbs, uses or excretes nutrients.
If your diet has limited variety because of food allergies or intolerance to certain foods, such as dairy products, you may benefit from a dietary supplement. Also, if you have a disease of your liver, gallbladder, intestines or pancreas, or if you've had surgery on your digestive tract, you may not be able to digest and absorb nutrients properly. In such cases, your doctor may recommend that you take dietary supplements. You consume less than 1,200 calories a day. Low-calorie diets limit the types and amounts of foods you eat and, in turn, the types and amounts of nutrients you receive. Unless monitored by a doctor, a low-calorie diet isn't usually recommended.

You smoke.
Tobacco decreases the absorption of many vitamins and minerals, including vitamin C, folate, magnesium and calcium. But dietary supplements won't make up for the major health risks caused by smoking. The safest option is to avoid all tobacco products. You're a vegetarian. If you're a vegetarian, you may not consume enough calcium, iron, zinc and vitamins B-12 and D. You can get these nutrients naturally from non-meat sources, such as fortified soy products, green leafy vegetables, legumes, whole-grain products and nuts. If you aren't able to regularly consume these foods, dietary supplements may be necessary.

You can’t drink milk or eat cheese and yogurt.
Dairy products like milk, yogurt, and cheese are the biggest dietary sources of calcium and vitamin D. The greatest health risk associated with a lack of calcium and vitamin D is osteoporosis, a disease characterized by fragile bones that are more susceptible to fractures. This is especially important for adolescent and young adult women.

You drink excessively.
Long-term excessive alcohol consumption can impair the digestion and absorption of several vitamins and minerals, including vitamin B-1, iron, zinc, magnesium and folate. In addition, you may substitute alcohol for food, resulting in a diet lacking in essential nutrients. Excessive drinking is defined as more than two drinks a day for men under age 65 and more than one drink a day for men over 65 and women. Taking dietary supplements, however, won't make up for the major health risks caused by excessive alcohol consumption You don't eat well. If you eat less than five total servings of fruits and vegetables daily, it may be difficult to get all of the vitamins and minerals your body needs. Also, if you eat only one or two times a day, you may be limiting the number and variety of servings you eat from the various food groups.

To improve your peak performance using NUTRITION: CLICK HERE