Health Benefits of Eating Seaweed

 

Seaweed or sea vegetables are forms of algae that grow in the sea.

Seaweed contains antioxidants and beneficial nutrients, including iodine, tyrosine, vitamins, and minerals. It can support heart and gut health and improve the blood sugar balance.

Here are benefits of seaweed:

1. Contains iodine and tyrosine, which support thyroid function

The thyroid gland releases hormones to help control growth, energy production, reproduction and the repair of damaged cells in the body. But the thyroid relies on iodine to make hormones. The daily value (DV) of iodine for adults is 150 mcg per day. And 1,100 mcg of iodine is the tolerable upper limit (TUL) for adults.

Seaweed has the unique ability to absorb concentrated amounts of iodine from the ocean.

Seaweed also contains an amino acid called tyrosine, which is used alongside with iodine to make two key hormones that help the thyroid gland do its job properly.

However, in Asian cultures, seaweed is commonly eaten with foods that can inhibit the uptake of iodine by the thyroid gland. These foods are known as goitrogens and are found in foods like broccoli, cabbage, and bok choy.

Additionally, seaweed is water-soluble, which means cooking and processing can affect its iodine content. For example, when kelp is boiled for 15 minutes, it can lose up to 99% of its iodine content.

2. Good source of vitamins and minerals

Seaweed also contains vitamins A, C, E and K, along with folate, zinc, sodium, calcium and magnesium.

The proteins present in some seaweeds contain all of the essential amino acids. This means seaweed can help ensure you get the full range of amino acids.

For example, spirulina is a rich source of vitamins like vitamins E, C, B6, minerals and fatty acids essential for maintaining a healthy immune system. Research finds that spirulina also boosts the production of white blood cells and antibodies that fight viruses and bacteria in the body. It is also high in the plant protein phycocyanin, which has antioxidant and anti-inflammatory properties. Chronic inflammation can contribute to cancer and other diseases.

Seaweed can also be a good source of omega-3 fats and vitamin B12.

Dried green and purple seaweed contain substantial amounts of vitamin B12. One study found 2.4 mcg of vitamin B12 in 4 to 8 grams of nori seaweed.

3. Contains a variety of protective antioxidants

Seaweed contains a wide variety of plant compounds that work together to have strong antioxidant effects.

In addition to containing the antioxidant vitamins A, C, and E, seaweed boasts a wide variety of beneficial plant compounds, including flavonoids and carotenoids. These have been shown to protect the body’s cells from free radical damage. Excess free radical production is considered to be an underlying cause of several diseases, such as heart disease and diabetes. 

A lot of research has focused on one particular carotenoid called fucoxanthin. It is the main carotenoid found in brown algae, such as wakame, and it has 13.5 times the antioxidant capacity of vitamin E. 

While the body does not always absorb fucoxanthin well, absorption may be improved by consuming it along with fat.

4. Provides fiber and polysaccharides that can support gut health

Seaweed is an excellent source of fiber, which is known to promote gut health.

Additionally, particular sugars found in seaweed called sulfated polysaccharides have been shown to increase the growth of “good” gut bacteria.

These polysaccharides can also increase the production of short-chain fatty acids (SCFA), which provide support and nourishment to the cells lining the gut.

5. Help lose weight by delaying hunger and reducing weight

As mentioned in the above, seaweed contains a lot of fiber, which provides little or no calories but can slow stomach emptying. This helps you feel fuller for longer and can delay hunger pangs.

Seaweed is also considered to have anti-obesity effects. In particular, animal studies suggest that fucoxanthin in seaweed may help reduce body fat.

In a 2023 clinical trial of 28 patients with metabolic syndrome, fucoxanthin was found to reduce body weight, blood pressure and triglyceride levels.

6. May reduce heart disease risk

Heart disease is the leading cause of death worldwide. Factors that increase the risk include high cholesterol, high blood pressure, smoking, and being physically inactive or overweight.

Seaweed may help reduce the blood cholesterol levels. A 2023 meta-analysis found that brown seaweed intake significantly decreased the levels of total cholesterol and LDL.

Protein in spirulina can reduce absorption of cholesterol, lowering cholesterol levels. This helps keep the arteries clear, reducing strain on the heart that can lead to heart disease and stroke-causing blood clots.

In fact, heart disease can be caused by excessive blood clotting. And seaweed contains carbohydrates called fucans, which may help prevent blood from clotting. One animal study found that fucans extracted from seaweed prevented blood clotting as effectively as an anti-clotting drug.

Researchers are also starting to look at peptides in seaweed. Initial studies in animals indicate that these protein-like structures may block part of a pathway that increases blood pressure in the body.

7. May help reduce the risk of type 2 diabetes

An 8-week study of 60 Japanese people revealed that fucoxanthin, a substance in brown seaweed, may help improve blood sugar control.

What is more, another substance in seaweed called alginate prevented blood sugar spikes in animals after they were fed a high-sugar meal. Alginate may reduce the absorption of sugar into the bloodstream.

A 2023 meta-analysis found that brown seaweed consumption significantly improved postprandial blood glucose, glycated hemoglobin (HbA1c), and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR).

Although seaweed is considered as a healthy food, there may be some potential dangers to consuming too much. This is because seaweed can absorb and store minerals in concentrated amounts. When seaweed contains large amounts of toxic heavy metals such as cadmium, mercury and lead, it can pose a health risk,

Luckily, a 2017 study analyzed the concentration of 20 metals in 8 different seaweeds from Asia and Europe and found that the levels of cadmium, aluminium and lead in 4 grams of each seaweed did not pose any serious health risks.

Nonetheless, if you consume seaweed regularly, there is the potential for heavy metals to accumulate in the body over time. Thus, if possible, buy organic seaweed, as it is less likely to contain significant amounts of heavy metals.