Kombu -- the Laminaria species of the kelp family -- is a variety of seaweed that brings a diverse range of nutrient, flavor and digestibility benefits to the table. Fresh or dried kombu can be used in a variety of bean, salad, soup and pickle dishes. It can also be an ingredient for sauces and stocks, or enjoyed on its own to introduce health benefits into your diet.
Calcium and Iron
Calcium and iron are two minerals naturally present in kombu. Calcium is an abundant mineral in the body that primarily serves skeletal functions. Recommended calcium intakes are 1,000 milligrams daily for adults 19 to 50. Just 2 tablespoons, or 10 grams, of kombu contain 16.8 milligrams of calcium, or approximately 1.7 percent of the daily recommended amount. Iron, a component of enzymes and proteins, plays critical roles in oxygen transport. The recommended dietary intakes for men 19 and older and women over 51 is 8 milligrams a day. Women 19 to 50 years of age require 18 milligrams daily. A 10-gram sample of kombu contains 0.3 milligrams of iron.
Kombu has the highest iodine content among seaweeds consumed in Japan. Iodine is an essential nutrient vital to hormone production and normal thyroid function. The recommended dietary allowance for adults is approximately 150 micrograms daily. According to a 2011 article published in "Thyroid Research," samples of 10 species of kombu from around the world averaged 1,542 micrograms per gram of dried kombu. The Linus Pauling Institute reports that 1/4 ounce of dried kombu can contain more than 4,500 micrograms.
Flavor and Digestibility
Kombu has been used for centuries as a flavor enhancer. In addition to the commonly recognized salty, sweet, sour and bitter taste qualities, kombu contributes a fifth taste, umami. This savory fifth taste is the result of taste receptors for glutamate -- or glutamic acid -- naturally present in kombu. Kombu also increases the digestibility of foods. The glutamic acid present in kombu helps break down the tough fibers in beans. Adding a soaked piece of kombu to the beginning stages of any dish can also introduce additional minerals into the diet. Kombu can also be used in the sprouting process to increase mineral content.
Other Benefits and Considerations
Other potential benefits include blood purifying, alkalizing, chelating, detoxifying, weight-loss and antioxidant properties As with any food, the quality of the seaweed depends on the source. Other factors, such as exposure to light, depth, temperature, tides, shores and the quantity of pollutants in the water, affect the quality of the kombu. Intake of excessive amounts of iodine can cause adverse reactions, including thyroid and skin problems. Contrary to some claims, research has not yet proved that sea vegetables, including kombu, can prevent cancer, cure certain diseases, or help with blood purifying, detoxifying or weight loss.
- Healing with Whole Foods; Paul Pitchford
- National Institutes of Health: Calcium
- National Institutes of Health: Iron
- USDA National Nutrient Database: Seaweed Kelp, Raw
- Thyroid Research: Assessment of Japanese iodine intake based on seaweed consumption in Japan
- Linus Pauling Institute: Iodine
- American Cancer Society: Sea Vegetables
- Food Matters: Seaweed Superfoods
- Chemical Senses: The Discovery of Umami