Besides their impressive nutritional profile, sea vegetables offer other health benefits. For centuries, Oriental medicine has recognized that sea vegetables contribute to general well-being and especially to the health of the endocrine and nervous systems. Over the last few decades, medical researchers have discovered a diet that includes sea vegetables reduces the risk of some diseases and helps the body eliminate dangerous toxins. In fact, surveys show that people living in areas where sea vegetables are regularly included in the diet tend to live longer, healthier lives.

For thousands of years, herbalists and pharmacologists around the world have tested and experimented with medicinal plants. Many modern medicines are either derived from plant extracts or are synthetic copies of substances originally derived from plants. Although there is a long tradition of using sea vegetables as medicine in Japan and China, modern medicine usually regards these remedies as mere folklore.

More recent medicinal treatments using sea vegetables, sea water, and mud from the ocean - such as thalassotherapy and algotherapy - are primarily external applications rather than internal medicines. Advocates of these therapies claim reduced or cured symptoms of hypertension, chronic rheumatism, gout, neuralgia, asthma, eczema, and even hemorrhoids.

Current interest in the medicinal value of sea vegetables began in 1927, when Professor S. Kondo, of Tohoku University, discovered that Japanese people living in regions where large amounts of sea vegetables were eaten regularly enjoyed a particularly long lifespan. For example, on Oki Island in the Shimane prefecture, where people eat an abundance of sea vegetables, there is the longest life expectancy in the nation. Before World War II, it was not uncommon to see Oki women who were 70 years old and older diving in the sea for abalone and red algae.

Since Kondo's field work, scientists have discovered that sea vegetables, in addition to being very nutritious, have antibiotic and anti-tumor properties. Sea vegetables have also been found to reduce blood pressure and serum cholesterol.

Diets high in sea vegetables have been associated with a lower risk for both colon and rectal cancers. During a study undertaken in Saitama Prefecture, Japan, 700 people were closely monitored for their daily food intake. The study showed that the more sea vegetables an individual eats, the less likely he or she was to develop colon and rectal cancer.

Sea vegetables have also been shown to inhibit breast cancer. In Japan laboratory tests showed that adding sea vegetables to the diet had a significant inhibitory effect on mammary tumor development. The onset of tumors was also delayed and the tumors were smaller.

Another Japanese animal study showed that consumption of sea vegetables inhibited the growth of implanted sarcomas by 89 to 95 percent. According to researchers, more than half of the animals studied showed complete regression. The report also showed promising results with leukemia.

A study done in the early 1960's seems to confirm the traditional belief that sea vegetables have an antibacterial effect in the intestines. Moreover, in the test tube seaweed extract was shown to be an effective antibiotic drug against common food poisoning bacteria. Sea vegetables have even been shown to inhibit the growth of herpes virus in test tubes.

As a result of this research, a few new medicines have been developed from this underwater harvest, such as laminin, which is used to reduce blood pressure. The most important discovery about sea vegetables for modern living, however, is their ability to cleanse the body of toxins. This powerful cleansing action has been linked to a substance called alginic acid.

Alginic acid is a polysaccharide that is abundant in those sea vegetables classified as brown algae, including kombu, hijiki, arame, and wakame. Scientific researchers, including a team led by Dr. Tanaka at McGill University, have demonstrated that alginic acid binds with any heavy metals found in the intestines, renders them indigestible, and causes them to be eliminated. So, any heavy metals, such as barium, cadmium, lead, mercury, zinc, and even radioactive strontium, that may be present in the intestines will not be absorbed by the body when alginic acid is present.

Doctors Seibin and Teruko Arasaki, Japanese scientists who have published several books about sea vegetables, also report this cleansing property of alginic acid in their book Vegetables From the Sea. They conclude, "Heavy metals taken into the human body are rendered insoluble by alginic acid in the intestines and cannot, therefore, be absorbed into body tissues."

What's more, Dr. Tanaka's research has shown that the alginic acid in sea vegetables actually helps bind and draw out any similar toxins that are already stored in our bodies, thus "lowering the body's burden."

Brown algae's natural affinity for binding with toxic non-organic heavy metals may soon be exploited by industry. Research conducted over the last decade has shown that treating heavy metal-bearing industrial effluents with brown algae is an effective and economical way to detoxify industrial waste. The process, called "biomass biosorption," is particularly effective for lead and cadmium.