In Asian cuisine seaweed is quite a common ingredient which most of us may be familiar with when we dine at Japanese restaurants. It is used in miso soup and nori sheets are used to make sushi amongst other things.
Eating seaweed is a fantastic way to add extra vitamins and minerals to your diet which in turn may protect you from certain diseases.
What Is Seaweed?
Seaweed is a general term used to describe many different species of algae and marine plants.
The most common edible types of seaweed are red, green, blue-green and brown which can be eaten fresh, dried, cooked or as a powdered supplement.
Common types of seaweed are:
Seaweed is Especially High in Many Nutrients: Edible seaweed contains a wide spectrum of vitamins, minerals and trace elements at higher levels than other common foods. Dried seaweed varieties such as spirulina and chlorella are especially rich sources of complete protein.
Depending on where seaweed is sourced it differs in nutritional value, but generally, 100g of seaweed provides you with:
Dried algae is more concentrated in nutrients. One tablespoon (8 grams) is sufficient to provide most of the nutrient amounts listed above.
Twice as much protein is found in spirulina and chlorella per portion. Unlike other types of algae, they also contain all of the essential amino acids required by the human body. This makes them complete sources of protein.
There is some debate when it comes to vitamin B12 which is found naturally in meat, poultry, eggs and dairy products. Some claim that seaweed is a good plant source of vitamin B12 and others claim whether the form of vitamin B12 found in algae is active in humans. If you are vegan it is best not to rely on this source and to supplement your vitamin B12.
Seaweed is a rich source of antioxidants and they also contain good amounts of sulfated polysaccharides (sPS), which are beneficial plant compounds thought to contribute to seaweed’s health benefits.
Promote Thyroid Function: Your thyroid requires a good intake of iodine to function properly. Iodine is found in large amounts in seaweed. Failure to get enough iodine from the diet can lead to hypothyroidism. The iodine RDI is 150 micrograms per day. This requirement can be met by eating several servings of seaweed per week. Keep in mind that certain varieties such as kelp, kombu and dulse tend to contain very high amounts of iodine and should not be eaten frequently, or in high amounts. Others, such as spirulina, contain very little, so don’t rely on them as your only source of iodine.
Improve Heart Health: seaweed contains a good source of soluble fiber and contains long-chain omega-3 fatty acids both of which are beneficial for heart health. In addition the sulfated polysaccharides (sPS) found in seaweed may have the ability to reduce blood pressure, prevent blood clotting, reduce LDL (the “bad”) cholesterol and total cholesterol levels.
A two-month study gave type 2 diabetics either a spirulina supplement or a placebo every day. The supplement group’s triglyceride levels dropped by 24%.
Participants in the spirulina group also improved their LDL-to-HDL cholesterol ratio, whereas the ratio in the placebo group worsened.
In another study, a daily spirulina supplement reduced participants’ total cholesterol levels by 166% more than the placebo group over the two-month study period.
Participants in the seaweed group also reduced their LDL cholesterol levels by 154% more than the placebo group.
Although these results seem promising, not all studies found similar results and more human studies are needed before strong conclusions can be made.
It May Stabilize Blood Sugar Levels: Researchers believe that certain compounds found in seaweed may play a beneficial role in stabilizing blood sugar levels and preventing type 2 diabetes . Fucoxanthin, antioxidant that gives brown algae its characteristic color, is thought to help reduce insulin resistance and stabilize blood sugar levels.
Seaweed May Help You Lose Weight: Researchers believe this may be due, in part, to seaweed’s ability to affect your levels of the weight regulating hormone leptin. Combined with seaweed’s high fiber content, this may help reduce hunger and enhance feelings of fullness. Fucoidan, a type of sPS found in seaweed, may enhance fat breakdown and prevent its formation.
Studies in obese participants report that those given a seaweed supplement for 12–16 weeks lost around 3.5 pounds (1.6 kg) more than those given a placebo. What’s more, seaweed is low in calories, making it a great low-calorie snack option.
Seaweed May Strengthen the Immune System: Marine plant compounds believed to have antioxidant, anti-allergenic and disease-protecting properties. Research shows that these compounds may have the ability to fight viruses such as herpes and HIV by blocking their entry into cells.
A recent study looked at the effects of taking seaweed supplements in HIV-positive women. Those given 5 grams of spirulina per day developed 27% fewer disease-related symptoms, compared to the placebo group.
However, no differences in immune cell levels were observed over the 12-week study period.
Additional studies are needed before strong conclusions can be made.
Seaweed May Improve Gut Health: It is rich in fiber, which can help prevent constipation and ensure smooth digestion.
It also contains agars, carrageenans and fucoidans, which are thought to act as prebiotics. Prebiotics are a type of non-digestible fiber that feed the beneficial bacteria in your gut.
The more good bacteria you have in your gut, the less space there is for harmful bacteria to thrive.
It May Reduce the Risk of Cancer: The presence of seaweed in your diet may help reduce your risk of developing certain types of cancer.
For instance, researchers believe that seaweed may help decrease estrogen levels, potentially reducing women’s risk of developing breast cancer.
The soluble fiber found in seaweed may also help protect against the development of colon cancer .
What’s more, some studies suggest that a class of compounds found in brown varieties, such as kelp, wakame and kombu, may help prevent the spread of cancerous cells.
Other Potential Benefits: Seaweed may offer some additional protection against metabolic syndrome, skin damage, bone disease and rheumatoid arthritis.
Is Eating Seaweed Safe?: Eating fresh seaweed is considered to be safe for most people. Consuming it regularly or in high amounts may cause some side effects. Depending on where they’re grown, some varieties of seaweed can contain high levels of mercury, cadmium, lead and arsenic.
The US Food and Drug Administration (FDA) regulates the levels of these chemicals and heavy metals in fresh seaweed. However, supplements are not regulated and may contain levels that are detrimental to health. It is important to find a company that you can trust.
A High Intake May Interfere With Kidney Function and Blood Thinners: Certain varieties of seaweed may contain high levels of sodium and potassium, which can be harmful to individuals suffering from kidney disease.
Seaweed also contains vitamin K, which may interfere with blood-thinning medications. Those taking blood thinners should make sure to check with a doctor before making it a regular part of their diet.
Some Are Very High in Iodine and May Interfere With Thyroid Function: While iodine is necessary for proper thyroid function, getting too much iodine can be harmful.
Kelp, dulse and kombu are types of seaweed with the tendency to contain very high levels of iodine. For instance, 25 grams of fresh kombu can contain close to 22 times more iodine than the safe daily limit.Therefore, these varieties should not be consumed too often, nor in large quantities.
Where to Find Seaweed and How to Eat It: In Cyprus seaweed can be purchased dried from most Asian corner shops, healthfood shops and some supermarkets.
In addition to their use for sushi, nori sheets can also easily be used to replace tortilla bread when making wraps.
Wakame can be soaked and made into a salad with some avocado, lettuce and pine nuts. I sometimes add it to my pulse dishes which is a good way to make them more nutritious as it releases all those minerals into your food.
Dried nori or dulse make for nice savory snacks. Or, try crumbling them over salads to add a dash of umami flavor.
Spirulina and chlorella can be added to smoothies, while kelp can be used instead of salt to add flavor to just about anything.
Many types of seaweed can also be incorporated into warm dishes, including pulses, soups, stews and baked goods. Get imaginative ! There’s no right or wrong way to go about it.
Barbara is a qualified nutritionist offering Health, Nutrition & Lifestyle Counseling. She gives Healthy weight loss advice and promotes the Mediterranean diet. She is the author of the Med Life Diet - creating healthy lifestyle habits and attitudes for life !