Seaweed

1. Supports Thyroid Health

Seaweed is one of the richest natural sources of iodine, a vital mineral required for producing thyroid hormones. Brown varieties such as kelp, kombu, and wakame are particularly high in iodine, which helps regulate metabolism and energy balance. However, moderation is key, as excessive iodine intake can also impact thyroid function.

2. Promotes Gut Health

It contains unique polysaccharides, such as alginate, fucoidan, and laminarin, which act as prebiotics—substances that feed beneficial gut bacteria. These compounds promote the growth of a healthy microbiota, enhancing digestion and supporting the intestinal barrier.

3. Rich in Antioxidants

Particularly red and brown varieties of seaweed contain potent antioxidants like phlorotannins, carotenoids (fucoxanthin), and vitamins A, C, and E. These compounds help protect cells from oxidative stress, reducing inflammation and supporting long-term health.

4. May Help Manage Blood Sugar and Cholesterol

Research shows that certain seaweed compounds may help regulate blood sugar and lipid levels. For instance, fucoxanthin and alginate have been found to slow glucose absorption and improve insulin sensitivity, while soluble fibres bind cholesterol and promote its excretion.

5. Supports Skin and Immune Health

The antioxidants and omega-3 fatty acids in seaweed contribute to skin elasticity and hydration, while polysaccharides may enhance immune response. Studies have shown that compounds in red seaweed, such as carrageenan, possess antiviral and antimicrobial properties.

6. Environmental and Nutritional Sustainability

This sea vegetable is a sustainable food source requiring no freshwater, fertilisers, or arable land. Its cultivation helps absorb carbon dioxide, supporting ocean health while providing nutrient-rich food for humans.

• Nori (Red): Commonly used in sushi, rich in protein, vitamin B12 (in bioavailable forms), and iron.
• Kombu (Brown kelp): High in iodine and glutamic acid, often used for flavourful broths.
• Wakame (Brown): Contains fucoxanthin, which may aid fat metabolism.
• Dulse (Red): Chewy and slightly smoky, rich in potassium and antioxidants.
• Sea lettuce (Green): High in magnesium and calcium, supports bone health.

Soups and Broths: Add dried kombu or wakame to soups for depth of flavour and nutrients.
Salads: Rehydrate seaweed and mix with sesame oil, vinegar, and cucumber for a refreshing side dish.
Smoothies: Add powdered seaweed (such as spirulina) for a nutrient boost.
Snacks: Dried nori or dulse flakes make excellent savoury snacks.
Cooking Broth: Use kombu as a base for umami-rich stocks or plant-based soups.

The Effects of Processing

Dried – retains minerals and fibre; may lose some vitamin C.
Boiled – slight reduction in iodine and antioxidants.
Roasted – concentrates flavour but can reduce certain heat-sensitive vitamins.
Frozen – preserves most nutrients with minimal loss.

• Thyroid Support: A study in Frontiers in Endocrinology (2020) confirmed that moderate seaweed intake provides sufficient iodine for hormone regulation without exceeding safe upper limits (Teas et al., 2020).
• Gut Health: A 2022 study in Nutrients demonstrated that seaweed polysaccharides enhance beneficial gut bacteria such as Bifidobacterium and Lactobacillus.
• Antioxidant Effects: According to a 2019 review in Marine Drugs, phlorotannins and fucoxanthin scavenge free radicals, reducing oxidative damage linked to chronic disease.
• Cardiometabolic Benefits: A 2021 human trial in Food Chemistry showed that brown seaweed extract reduced post-meal blood glucose by 12% and LDL cholesterol by 9% after eight weeks.
• Anti-Inflammatory and Immune Support: Compounds like fucoidan exhibit strong anti-inflammatory and antiviral activity, as evidenced in studies on influenza and herpes viruses.

Seaweed is a nutrient powerhouse from the ocean, offering a unique combination of minerals, antioxidants, and fibres that benefit thyroid function, gut health, and cardiovascular well-being. With sustainability on its side and versatility in the kitchen, seaweed deserves its reputation as a true functional food.

Including modest amounts in your diet—whether through soups, salads, or snacks—can help enhance your nutritional intake while supporting a balanced, eco-friendly diet.

As Dr William Li notes in Eat to Beat Disease, the right foods can activate the body’s natural defence systems and enhance overall wellbeing. Whether sprinkled over breakfast oats, blended into smoothies, or enjoyed raw as a mid-afternoon snack, almonds make an easy and delicious addition to any balanced diet — proof that small daily choices can have lasting impact on health and vitality.

1. Teas, J., et al. (2020). Seaweed and iodine nutrition: balancing benefits and risks. Frontiers in Endocrinology. https://doi.org/10.3389/fendo.2020.00579
2. Cherry, P., et al. (2019). Marine algal antioxidants and their potential role in human health. Marine Drugs, 17(9): 491. https://doi.org/10.3390/md17090491
3. Jung, H.A. et al. (2021). The effects of brown seaweed extracts on glucose and lipid metabolism. Food Chemistry, 352: 129359. https://doi.org/10.1016/j.foodchem.2021.129359
4. Wells, M.L. et al. (2017). Seaweed and human health. Phytochemistry Reviews, 16(2): 371–390. https://doi.org/10.1007/s11101-016-9470-9