Exploring the benefits of seaweed – and how to eat it

From thyroid support to heart health, seaweed is often labelled a superfood – but what does the evidence actually say, and how can you slip it into your meal rotations?

Seaweed may not be the first thing you toss into your trolley when you’re doing the weekly shop, yet it has nourished coastal communities for centuries. From Japanese nori sheets to Welsh laver, this slippery marine plant boasts a bounty of health benefits worth being aware of. But what is it that makes algae a worthy addition to your pantry? Let’s untangle this together.

One of seaweed’s most well-known benefits is hidden in its iodine content. Iodine is essential for healthy thyroid function, which, in turn, supports metabolism and energy levels and can indirectly influence mood. In the UK, mild iodine deficiency is not uncommon, particularly among people who avoid dairy or fish, and with seaweed also providing the amino acid tyrosine (which works alongside iodine to support the production of key hormones needed for healthy thyroid function), even just small amounts of seaweed could offer a healthy boost.

With that said, some varieties, particularly kelp, contain very high levels of iodine. When consumed in excess, this can actually disrupt thyroid function – potentially leading to both overactive and underactive states. As with many nutrient-rich foods, the benefits here lie in moderation and should be discussed with your doctor if you have any concerns.

But seaweed also stands out for its nutrient density, providing a host of vitamins and minerals, including vitamin K, vitamin A, iron, calcium, and magnesium – all while being low in calories. For those looking to add more nourishment without significantly increasing energy intake, this makes it an appealing option.

This underwater superfood has even been linked to better heart health. A 2023 meta-analysis published in the journal Marine Drugs found that brown seaweed intake significantly decreased the levels of total cholesterol and LDL (also known as ‘bad’ cholesterol), which indicates that it could reduce your risk of heart disease. Seaweed also contains carbohydrates called fucans, which have been shown to have anti-clotting effects in lab trials – another cause of heart disease.

However, it’s important to keep expectations realistic; seaweed alone won’t transform your cardiovascular health, but it can certainly play a supportive role in a balanced diet.

From shore to shopping list

Seaweed can look, feel, and taste unfamiliar at first, but adding algae into your diet doesn’t require any special techniques or brand-new recipes. Often, simple additions or swaps are all you need to get started!

One of the easiest entry points is nori, the thin sheets commonly used for sushi. These can be torn into strips and sprinkled over Asian dishes such as rice, noodles, or salads. They also work beautifully as a topping for avocado toast or stirred through scrambled eggs, offering an introduction to the ingredient without overpowering the entire dish.

A small handful of dried wakame can work wonderfully when added to miso soup or vegetable broths, where it softens quickly and blends with other ingredients. This approach allows seaweed to complement a dish rather than being the star of the show, which can make it more approachable for those who are unsure about the flavour.

For something more familiar, seaweed flakes or seasoning blends can be used in much the same way as herbs or spices. Sprinkling them over roasted vegetables, popcorn, or even potatoes can add a salty, umami twist while reducing the need for more salt.

For those short on time, there are grab-and-go options available too, from seaweed snack packs to shop-bought sushi. While these can be a useful starting point, it’s worth keeping an eye on added salt, sugar, and flavourings, which can sometimes overshadow the natural benefits of the raw ingredient.

As with any new food, it helps to start small. Seaweed’s flavour is distinctive, and preferences can take time to develop, so rather than forcing it into every meal, a more sustainable approach is to simply experiment and stick with what works for you. You never know, your next favourite green could be found in the big blue.