If you’re a sushi fan, it’s pretty likely you have tried seaweed. Rich in vital nutrients and antioxidants, seaweed has been consumed for centuries, particularly in China and Japan, where several different strains are eaten regularly. A member of the algae family, edible seaweed comes in three varieties – green, red and brown. Brown varieties, such as kelp and wakame, remain the most popular among diners, while red seaweed (nori) is used to make sushi.

Today, seaweed can be found in the majority of major supermarkets. Asian supermarkets also stock a wide range of edible sea vegetables, including fresh, dried and powdered varieties.

The health benefits linked to eating seaweed

There are lots of reasons to up your seaweed intake. Not only is seaweed great for your digestive health, it may improve heart health and help to regulate hormone production too. Wakame, in particular, has been shown to prevent high blood pressure in a number of animal species, while arame is unusually rich in iodine, calcium, folate and magnesium.

Lately, a 25 year study found that the world’s longest-lived population, the Okinawans, who consume several portions of sea vegetables daily, seldom suffer from high cholesterol, heart attack or stroke. Researchers concluded that sea vegetables support heart health and help to lower blood pressure.

Edible seaweed is a fantastic source of iodine, which supports thyroid function and helps to regulate hormone production. Consuming healthy quantities of iodine is critical; thyroid malfunction can result in rapid weight loss, high cholesterol, fatigue and muscle weakness. Mild iodine deficiency manifests gradually and subtly. Just one gram of edible brown seaweed contains more than fifty times your recommended daily allowance of iodine, however.

Why and how often should you eat seaweed?

Seaweed is a low calorie, highly nutritious vegetable, which can be used to enhance the flavour of other foodstuffs. So called “functional foods”, by which I mean fortified or vitamin-enriched products, often contain seaweed or seaweed extract, which can help you feel fuller for longer and give your digestive system a much-needed boost.

In the Caribbean and Ireland, seaweed-based soups and tonics are often given to the sick reducing phlegm and preventing swelling. Seaweed has also been shown to ease hangover symptoms and boasts powerful antioxidant properties.

In general, dishes containing seaweed are great for our bodies. Think about it, while you’re unlikely to order seaweed with a side of chips, you may well find yourself tucking into salads, miso soups, tofu dishes, raw fish and vegetable stews along with your seaweed.

While you may be tempted to add seaweed to all of your food from now on, go steady. Seaweed is high in potassium, too much of which can lead to heart palpitations among those with kidney problems. Similarly, consuming too much iodine can be just as damaging as consuming none at all. Eat seaweed in moderation. Two to three tablespoons of seaweed each week, two to three servings of sushi, or three to four bowls of miso soup will give you the nutritional boost you require.

Nutrient profile

Seaweed is low in saturated fat and very low in cholesterol. It’s a great source of vitamins A, C, E and K, riboflavin, folate, calcium, niacin and manganese. Edible seaweed is also rich in copper and magnesium. However, seaweed also contains high levels of sodium, which can impact upon kidney function.