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Sea vegetables

Western cultures are only recently beginning to enjoy the taste and nutritional value of sea vegetables, often referred to as seaweed, that have been a staple of the Japanese diet for centuries. The various varieties of sea vegetables can be found in health food and specialty stores throughout the year and are also becoming much easier to find in your local supermarkets with their rise in popularity.

Sea vegetables can be found growing both in the marine salt waters as well as in fresh water lakes and seas. They commonly grow on coral reefs or in rocky landscapes, and can grow at great depths provided that sunlight can penetrate through the water to where they reside since, like plants, they need light for their survival. Sea vegetables are neither plants nor animals but classified in a group known as algae.


Health Benefits

Why would anyone want to eat seaweed? Because sea vegetables offer the broadest range of minerals of any food, containing virtually all the minerals found in the ocean--the same minerals that are found in human blood. Sea vegetables are a very good source of the B-vitamin folate, and magnesium, and a good source of iron, calcium, and the B-vitamins riboflavin and pantothenic acid. In addition, seaweeds contain good amounts of lignans, plant compounds with cancer-protective properties.

Cancer Protection

Lignans have been shown to inhibit angiogenesis, or blood cell growth, the process through which fast-growing tumors not only gain extra nourishment, but send cancer cells out in the bloodstream to establish secondary tumors or metastases in other areas of the body. In addition, lignans have been credited with inhibiting estrogen synthesis in fat cells as effectively as some of the drugs used in cancer chemotherapy. In postmenopausal women, fat tissue is a primary site where estrogen is synthesized, and high levels of certain estrogen metabolites (the 4OH and 16OH metabolites) are considered a significant risk factor for breast cancer.

In addition to lignans, seaweeds are a very good source of the B-vitamin folic acid. Studies have shown that diets high in folate-rich foods are associated with a significantly reduced risk for colon cancer.

Promote Healthy Thyroid Function

Sea vegetables, especially kelp, are nature's richest sources of iodine, which as a component of the thyroid hormones thyroxine (T4) and triiodothyronine (T3), is essential to human life. The thyroid gland adds iodine to the amino acid tyrosine to create these hormones. Without sufficient iodine, your body cannot synthesize them. Because these thyroid hormones regulate metabolism in every cell of the body and play a role in virtually all physiological functions, an iodine deficiency can have a devastating impact on your health and well-being. A common sign of thyroid deficiency is an enlarged thyroid gland, commonly called a goiter. Goiters are estimated to affect 200 million people worldwide, and in all but 4% of these cases, the cause is iodine deficiency.

Nutrient Prevention of Birth Defects and Cardiovascular Disease

The folic acid so abundant in sea vegetables plays a number of other very important protective roles. Studies have demonstrated that adequate levels of folic acid in the diet are needed to prevent certain birth defects, including spina bifida. Folic acid is also needed to break down an intermediate dangerous chemical produced during the methylation cycle called homocysteine. (Methylation is one of the most important cellular cycles through which a wide variety of important chemicals are produced.) Homocysteine can directly damage blood vessel walls, and high levels of this chemical are associated with a significantly increased risk of cardiovascular disease and stroke. Flavoring soups and stews with seaweeds or using seaweed in salads is a smart strategy, especially for those dealing with atherosclerosis or diabetic heart disease.

Sea vegetables pack a double punch against heart disease. In addition to their folic acid, sea vegetables are a very good source of magnesium, which has also been shown to reduce high blood pressure and prevent heart attack.

Anti-Inflammatory Action

Some sea vegetables have been shown to be unique sources of carbohydrate-like substances called fucans, that can reduce the body's inflammatory response. Plus, as noted above, seaweeds are a very good source of magnesium, the mineral that, by acting as a natural relaxant, has been shown to help prevent migraine headaches and to reduce the severity of asthma symptoms.

Relief for Menopausal Symptoms

Seaweeds' supply of relaxing magnesium may also help restore normal sleep patterns in women who are experiencing symptoms of menopause. And the lignans in sea vegetables can act as very weak versions of estrogen, one of the hormones whose levels decrease during the menopausal period. For women suffering from symptoms such as hot flashes, seaweeds' lignans may be just strong enough to ease their discomfort.

Stress Relief

Seaweeds support us through stressful situations by supplying not only magnesium, but pantothenic acid and riboflavin--two B-vitamins necessary for energy production. Pantothenic acid is especially important for the health of the adrenal glands. The adrenals control many body functions and play a critical role in resistance to stress. When supplies of necessary nutrients like pantothenic acids are inadequate, stressful times can exhaust the adrenal glands resulting in chronic fatigue, reduced resistance to allergies and infection, and a feeling of being overwhelmed or overly anxious.

Description

Sea vegetables, often called seaweed, are one of the Neptune’s beautiful jewels, adorning the waters with life and providing us with a food that can enhance our diets, from both a culinary and nutritional perspective. Sea vegetables can be found growing both in the marine salt waters as well as in fresh water lakes and seas. They commonly grow on coral reefs or in rocky landscapes, and can grow at great depths provided that sunlight can penetrate through the water to where they reside since, like plants, they need light for their survival. Yet sea vegetables are not plants nor animals - they are actually known as algae.

There are thousands of types of sea vegetables that are classified into categories by color, known either as brown, red or green sea vegetables. Each is unique, having a distinct shape, taste and texture. Although not all sea vegetables that exist are presently consumed, a wide range of sea vegetables are enjoyed as foods. The following are some of the most popular types: Nori: dark purple-black color that turns phosphorescent green when toasted, famous for its role in making sushi rolls. Kelp: light brown to dark green in color, oftentimes available in flake form. Hijiki: looks like small strands of black wiry pasta, has a strong flavor. Kombu: very dark in color and generally sold in strips or sheets, oftentimes used as a flavoring for soups. Wakame: similar to kombu, most commonly used to make Japanese miso soup. Arame: this lacy, wiry sea vegetable is sweeter and milder in taste than many others Dulse: soft, chewy texture and a reddish-brown color.

History

The consumption of sea vegetables enjoys a long history throughout the world. Archaeological evidence suggests that Japanese cultures have been consuming sea vegetables for more than 10,000 years. In ancient Chinese cultures, sea vegetables were a noted delicacy, suitable especially for honored guests and royalty. Yet, sea vegetables were not just limited to being a featured part of Asian cuisines. In fact, most regions and countries located by waters, including Scotland, Ireland, Norway, Iceland, New Zealand, the Pacific Islands and coastal South American countries have been consuming sea vegetables since ancient times.

Presently, Japan is the largest producer and exporter of sea vegetables. This may explain why many of these precious foods are often called by their Japanese names.

How to Select and Store

Look for sea vegetables that are sold in tightly sealed packages. Avoid those that have evidence of excessive moisture. Some types of sea vegetables are sold in different forms. For example, nori can be found in sheets, flakes, or powder. Choose the form of sea vegetables that will best meet your culinary needs.

Store sea vegetables in tightly sealed containers at room temperature where they can stay fresh for at least several months.

How to Enjoy

For some of our favorite recipes, click Recipes.

A Few Quick Serving Ideas:

Make homemade vegetable sushi rolls by wrapping rice and your favorite vegetables in sheets of nori.

Slice nori into small strips and sprinkle on top of salads.

Keep a container of kelp flakes on the dinner table and use instead of table salt for seasoning foods.

Combine soaked hijiki with shredded carrots and ginger. Mix with a little olive oil and tamari.

When cooking beans, put kombu in the cooking water. It will not only expedite the cooking process, but will improve beans' digestibility by reducing the chemicals that can cause flatulence.

Add sea vegetables to your next bowl of miso soup.

Safety

Sea vegetables are not a commonly allergenic food, are not included in the list of 20 foods that most frequently contain pesticide residues, and are also not known to contain goitrogens, oxalates, or purines.

Nutritional Profile

Introduction to Food Rating System Chart

The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents (similar to other information presented in the website, this DV is calculated for 25-50 year old healthy woman); the nutrient density rating; and, the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. For more detailed information on our Food and Recipe Rating System, please click here.

Kelp
0.25 cup
8.60 calories
Nutrient Amount DV
(%)
Nutrient
Density
World's Healthiest
Foods Rating
folate 36.00 mcg 9.0 18.8 very good
magnesium 24.20 mg 6.0 12.7 very good
calcium 33.60 mg 3.4 7.0 good
iron 0.57 mg 3.2 6.6 good
tryptophan 0.01 g 3.1 6.5 good
World's Healthiest
Foods Rating
Rule
excellent DV>=75% OR Density>=7.6 AND DV>=10%
very good DV>=50% OR Density>=3.4 AND DV>=5%
good DV>=25% OR Density>=1.5 AND DV>=2.5%

In Depth Nutritional Profile for Sea vegetables

References

  • Blondin C, Chaubet F, Nardella A, et al. Relationships between chemical characteristics and anticomplementary activity of fucans. Biomaterials 1996 Mar;17(6):597-603.
  • Blondin C, Fischer E, Boisson-Vidal C, et al. Inhibition of complement activation by natural sulfated polysaccharides (fucans) from brown seaweed. Mol Immunol 1994;31(4):247-253.
  • Ensminger AH, Esminger M. K. J. e. al. Food for Health: A Nutrition Encyclopedia. Clovis, California: Pegus Press; 1986.
  • Goldbeck N, Goldbeck D. The Healthiest Diet in the World. Plume (Penguin Putnam Inc.) NY, 2001, pp 378-80.
  • Terry P, Jain M, Miller AB et al. Dietary intake of folic acid and colorectal cancer risk in a cohort of women. Int J Cancer 2002 Feb 20;97(6):864-7.
  • Wood, Rebecca. The Whole Foods Encyclopedia. New York, NY: Prentice-Hall Press; 1988.

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