Sea Lettuce is an edible green seaweed / algae that’s found worldwide and is also known as Green Laver, Ulva or Ulva lactuca, lactuca being Latin for “lettuce”.
Sea lettuce – Ulva lactuca has a thin and flat leafy-like appearance with ruffle edges. Being only 2 cell layers thick it is translucent but surprisingly strong. The plant is a pale green colour when young, becoming a vibrant bright green when mature and turning dark green when old.
The Sea Lettuce plants grow attached, without a stipe, to rocks, gravel, reef flats, shells and other seaweeds by a disc-shaped root-like holdfast. I can also be found free-floating in the sea. The fronds within the water resemble lettuce leaves, hence the name Sea Lettuce. The plant can grow up to 45 cm long and 30 cm across.
Being mainly a shallow water seaweed, it is found on sheltered and intertidal exposed rocks and shores, and in stagnant tide pools and shallow waters near the low watermark, but has been recorded at depths of 75 feet or more.
It thrives in brackish waters, particularly in waters enriched with organic nutrients, but can thrive in moderate levels of nutrients.
It is fairly common along the Irish Shoreline and in temperate and colder seas.
Sea lettuce is a perennial plant and grows new fronds each spring, but it can be found all the year round, growing best during the summer months because of longer daylight hours and the water temperature becomes ideal for rapid reproduction.
Large volumes of sea lettuce often thrive in areas that are nutrient-enriched from sewage outfalls and other farming run-off pollutants that get into streams and rivers. It is a good indicator species to monitor as it grows where there are of high levels of pollutants that would suffocate many other aquatic plants.
Sea Lettuce Nutritional Information
Nutritionally Ulva is a rich source of iodine, aluminum, manganese, magnesium, sodium, potassium, copper, zinc, trace elements, and ash. It is high in iron (15 times greater than egg yolk or spinach) and calcium.
Green (Ulva) seaweed contains 27% protein, which is comprised of all 9 essential amino acids including Lysine which is the amino acid that is typically deficient in most vegetarians. 50% is comprised of sugar and starch, and it contains less than 1% fat. It is also high in protein and contains a plethora of essential Vitamins (A, C, E, riboflavin, pantothenic acid, niacin, B12, choline, biotin, folic acid, and thiamin). Sea lettuce provides considerable amounts of dietary fiber (31%), and because this seaweed is a good source of vitamin B-12 which is important for vegans and vegetarians.
Health uses of Sea Lettuce
Sea lettuce is especially popular in Okinawan in Japan and Crete in Greece. Sea vegetables like sea lettuce dominate the diets of these people, so it is possible that these mineral-rich foods are responsible for such longevity and healthfulness.
The Okinawa Centenarian Study found that the residents of Okinawa are 82 percent less likely than the average American to suffer from coronary heart disease. Furthermore, a study published in the September 2008 edition of the British Medical Journal found that the mortality rate of those who favour a Mediterranean diet is 9% lower than those who favour the standard Western diet.
Antioxidant properties – Sea Lettuce is rich in vitamins and antioxidants that can neutralize free radical damage, thereby guarding us against a myriad of health conditions such as macular degeneration and cancer. Additionally, this nutrient-rich seaweed has excellent skin-boosting properties.
Sea Lettuce contains natural photosynthetic pigments that give it that green colour. It has a high concentration of A-Chlorophyll, B-Chlorophyll, Xanthophylls, Lotein, Beta and Gamma Carotene, Siphonxantine and Siphonein.
Beta Carotene is essential to your eye’s health and has antioxidant properties.
Lotein is essential for repairing sun damage to your eyes and UV rays on your skin and acts as an antioxidant.
Promotes bone health – Calcium is certainly good for our bones and teeth, but we also need magnesium to help us absorb it. Since sea lettuce is nutrient dense in both minerals (100 grams of sea lettuce provide us with 490 milligrams of calcium and 3200 milligrams of magnesium) it is an ideal food for building bones and to help in preventing osteoporosis.
Weight loss properties – Sea lettuce is an excellent weight loss food: One 100 gram serving contains only 130 calories, 0.6 grams of fat, and 29.1 grams of dietary fiber.
Culinary Uses of Sea Lettuce
Sea Lettuce – Ulva lactuca can be eaten raw in salads but it also used in cooking, soups, with meats and fish. It has a distinctive sea flavor and odor.