
Edible seaweed, often referred to as sea vegetables, refers to marine algae that can be consumed by humans. Although seaweed has been utilised as a food source for millennia, it has regained popularity in recent decades for use in dishes such as salads, sushi, and snacks.
Edible seaweeds can be categorised based on their chemical and nutritional make-up. The main categories are red, brown, and green algae, as well as single-celled microalgae you may have heard of such as chlorella or spirulina1.
Is seaweed good for you?
Sea vegetables are a low-energy, nutrient-rich plant food. Seaweed contains good levels of dietary fibre, plant-based protein, vitamins, and minerals, as well as bioactive plant compounds that support health over and above the nutrients they contain.
Seaweed has been found to contain high levels of polyphenolic compounds including catechin, and gallic acid.
Polyphenols provide health benefits through antioxidant, anti-cancer, anti-viral and anti-inflammatory properties that contribute to reduced risk of heart disease, death from cancer and a longer life expectancy2.
Fibre is an over-looked and under-consumed component of plant food. Seaweed provides both soluble and insoluble forms that promote beneficial gut bacteria, add faecal bulk and reduce transit time, making them crucial for good gut health.
Seaweed is a high-fibre food and can contain between 29g and 62g of fibre per 100g of dry weight; a range that is higher than many terrestrial fruits and vegetables3.
Although protein content varies, seaweed can contain up to 47% protein based on dry weight4. Nori, a type of red seaweed, generally provides the most. The protein content of seaweed varies across the season however, and how well humans can absorb and use this protein remains unclear3.