Kelp Benefits 2024: The Oceanic Plant That Can Boost Your Health

Asian populations have less prevalence of many types of cancer than western countries, according to epidemiological studies^[1]. One of the main reasons is dietary habits. Asian diets include many sea-foods. Kelp is one of them. 

Kelps are large brown algae (brown seaweed) that are sustainable and healthy foods.  

Seaweeds can grow without fertilizing, using carbon dioxide and nutrients from the surrounding ocean, and they have a low carbon footprint when cultivated.

It contains a polysaccharide, alginate^[2], and important trace elements such as iodine, magnesium, potassium, iron, and calcium. 

Let’s explore how sea kelp benefits your health. 

6 Benefits Of Kelp For Your Health

Kelps are an important iodine source among seaweeds. They also include vitamin K, folate, magnesium, a natural fiber called alginate, flavonoids, and carotenoids. Each of these has different health benefits.  

Thyroid Function

Iodine is an essential trace element for thyroid gland function. The thyroid hormones include iodine in their composition. Iodine, responsible for thyroid health, is also important for growth and metabolism. 

Iodine deficiency leads to goiter. The symptoms are slower metabolism, weight gain, and cognitive problems such as learning difficulties and fatigue. Iodine deficiency symptoms are called hypothyroidism, which is a disease of the thyroid gland when it cannot produce enough thyroid hormones. 

The daily recommended intake is 150 μg iodine per day for adults according to World Health Organization^[3], and the upper level of tolerable intake is 600 μg/day for adults and 200 μg/day for children, according to European Commission Scientific Committee on Food^[4]. Both too low or too much iodine can be harmful to the thyroid gland.

Kelps contain a great amount of iodine. Taking kelp supplements is commonly used for iodine supplementation.  

Kelp supplement consumption for 4 weeks, both in low or high^[5] doses, increased thyroid stimulation via increased TSH hormone levels in normal-thyroid (euthyroid) subjects. Similar effects with kelp supplement, compared to iodine supplementation, were seen. Endocrine Function And Women’s Health

Eating kelp may also have anti-estrogenic effects^[6] by inhibiting estrogen binding to its receptors. Sea kelp may contribute to cancer prevention in women with anti-estrogenic function.  

Kelp-based extract leads to controlled cell death^[7] on breast, endometrial, and ovarian cancer cell lines, suggesting that it has anti-tumorigenic activities in female cancers.

Obesity And Diabetes

The effects of eating kelp on blood glucose levels were also investigated in different studies. After 6 weeks of treatment, treatments with brown seaweed extract, combined with chromium picolinate, lowered blood sugar both in the fed and hungry state in people with anormal blood sugar levels^[8] (dysglycemia). Weight loss of subjects was also observed.  

In another study, brown seaweed consumption allowed a reduction^[9] in the insulin needed for patients.  Researchers added that the supplement form of brown seaweed didn’t show any adverse effects. 

Sea kelp supplements resulted in a significant decrease^[10] in waist circumference when it was used with chromium picolinate, as in previous studies. Blood insulin and sugar levels also decreased significantly after 6 weeks.

Polyphenols^[11] may help weight management by inducing thermogenesis and inhibiting inflammation in fat tissue. The phlorotannins, a major polyphenol of brown algae, might be the major factor in explaining the health benefits of kelp.

Gut Health

Kelp consists of the most dietary fiber content among all other seaweeds, as well as plants. 32.8% of water-soluble and 17.9% of water-insoluble dietary fibers are present in kelp.

Kelp extracts and supplements may have prebiotics^[12] potential regulatory effects on gut microbiota due to their high content of natural fiber. It is thought^[13] that kelp, as a sustainable product, will be important for innovative prebiotic production. 

Kelps are also used in probiotic capsules^[14] to improve the storage stability and gastrointestinal survival rate of probiotics. Its hydrogel consistency makes for excellent capsular insulation, allowing probiotics to survive until they reach the colon.

Skin, Hair, And Bone Health

The kelp extract or supplements have an inhibitory effect^[15] on bone resorption,  which helps maintain bone density and health. Special compounds such as fucoxanthin^[16] from seaweeds are responsible for these health benefits.

Kelp benefits for the skin are based on the functional carbohydrate content of seaweeds. Beta-glucan^[17] is one of the specific carbohydrates that seaweeds contain which maintains the cell wall. Marine seaweed carbohydrates^[18] have moisturizing effects which are used in cosmetic products, including cosmetic benefits for hair. 

Allergy And Anti-Inflammatory Effects

Kelp intake can boost the Immune system. In a paper, researchers cite kelp functions in 4 steps^[19] of immunity by its phytosterols, polyphenols, fucoxanthins, and fucoidans content. 

Epithelial prevention: Epithelial cells are cells found in the structure of our intestinal wall. It prevents the passage of harmful substances entering the body or creates an immune response when necessary. It can be thought that kelps may support immunity by protecting intestinal integrity.

Anti-oxidant activity: The antioxidant content of kelps prevents disease-causing free radicals. Polyphenols are important components that prevent free radicals from damaging cells and tissues. This feature is responsible for its anti-cancer effects. 

Anti-allergic effects: Exaggerated responses of immunity can sometimes cause allergic reactions. Seaweed components, which have regulatory effects on the responses of immune cells, may have an anti-allergic effect.

Anti-inflammatory activity during chronic diseases: All these effects together are effective in the prevention of metabolic diseases caused by chronic inflammation. In this respect, the consumption of brown seaweed has long-term health outcomes.

From that same paper:

Image 1^[19]: Four roles of kelps on immunity. 

Cancer Prevention

In some cancer types, the fucoidan content of kelps can inhibit^[20] cancer metastasis and progression. Brown seaweed is rich in sulfated polysaccharide fucoidans. Also, it was mentioned above that the anti-estrogenic effects of kelps may retard breast, endometrial, and ovarian cancers.

What Is Kelp?

According to the Food and Agriculture Organization (FAO) database, global aquaculture production of seaweed has more than tripled, from 10.6 million tons in 2000 to 32.4 million tons in 2018 (FAO, 2020). 

Currently, seaweeds have a wide range of uses. Besides its use as a food source, seaweeds are a good source of structurally diverse bioactive compounds with significant pharmaceutical and biomedical potential for developing functional materials such as nutraceuticals and cosmetics. Consider how many medications need to bypass the breakdown from gastric acidity; kelp use in capsules makes that possible. 

Each year, a considerable number of new bioactive secondary metabolites are isolated from seaweeds. These compounds are typically investigated in various studies to evaluate their potential as anticancer, anti-inflammatory, antiviral, antihypertensive, antibacterial, and antidiabetic agents. Brown seaweeds–kelps–are one of them.

It is one of the richest iodine-containing brown seaweed from the algae family. An easily available food source, edible seaweeds have been consumed by coastal communities since ancient times, especially in Asia.

Nutritional Value

• 100 g raw kelp includes^[21] (daily value, DV%);
• 43 calories 
• 9.6 g total carbohydrate (3%)
• 1.7 g protein (3%)
• 1.3 g dietary fiber (5%)
• 233 mg sodium (10%)
• 121 mg magnesium (29%)
• 168 mg calcium (13%)
• 2.9 mg iron (16%)
• 89 mg potassium (2%)
• 180 mcg folate (45%)
• 66 mcg vitamin K (55%)
• Also 100 g kelps contain 81.58 g water.

Side Effects Of Kelp

Excessive iodine can be toxic and leads to thyroid gland inflammation. It can also affect thyroid hormone production negatively. As such, too much kelp consumption may lead to thyroid overstimulation. Kelp supplements should be used wisely to avoid thyroid impact.

When you consume excessive kelp, side effects might be seen:

• itching 
• allergic reactions
• rashes
• tightness in the chest
• trouble breathing
• trouble sleeping
• arrhythmia
• unusual bleeding 
• cramps
• nervousness 

The iodine content^[22] in one serving of seaweed food in the market was found to be in a wide range (from 30 to 25000 μg). The daily dose of seaweed supplement products’ iodine content ranged from 5 to 5,600 μg. In this study, one dose or one portion of 54 products examined had excessive iodine content exceeding the tolerable upper intake level (UL) previously mentioned.

Due to the tendency of drug interactions, you should avoid kelp consumption if you use digoxin, potassium supplements, spironolactone, thyroid drugs, supplements, etc. Due to the high amount of vitamin K, if you use the drug warfarin to avoid blood clots, you shouldn’t consume kelps. 

Toxic metals^[23] can also accumulate in seaweeds. Heavy metals can interfere with and lead to dysfunction in the ion transport in cell membranes, so they are highly toxic, leading to liver, nerve, and bone tissue damage.

Ways To Eat Kelp & Safety Tips

Kelps are especially high in iodine, thus daily intake of 3–6 g of dried kelp is sufficient for adequate dietary iodine. Regarding the bioavailability of iodine content from kelps, up to 11 g of processed-dried kelp can be consumed^[24] and not exceed the daily recommended upper intake for adults.

To get benefits from kelp without side effects, it can be used in recipes instead of consuming it directly. 

While buying seaweed-based market products, you should be aware of the source of the seaweed, water quality, processing, etc., which can be helpful to assess the safety^[23] of the product and identifying potentially toxic compounds.

Care should be taken to identify representative samples that have iodine analysis to avoid significant variability between the iodine content provided on the food packaging and the actual iodine content. If kelp-based supplements are used, be sure of how much total iodine you’re consuming.

Soups and Salads: Fresh kelp can be a good ingredient for your soup and salads. With its low-calorie content, it is a suitable choice for vegan & vegetarian, lectin-free diets, or many other dietary approaches for weight loss or wellness. Also, it can be consumed as kelp noodles, a traditional kind of Asian soup.

Kelp powder: Kelp powder increases the nutrient in your meal. If you add kelp powder to your meals responsibly, you can increase dietary vitamin and mineral intake while still being aware of how much iodine that powder adds

Kelp flakes: You can sprinkle dried kelp flakes as a spice on meals, yogurt, or salted oat bowls.

Vegetable juices: You can prepare vegetable shakes and juices by adding raw, dried, or powdered kelps. 

Conclusion

Kelps contain many ingredients that can increase food functionality (e.g., texturizers such as sodium alginate) and flavor (e.g., glutamic acid). Therefore, the likelihood of including kelps in foods is high. In addition, kelps contain many important nutrients such as vitamins, minerals, and fiber. However, iodine and heavy metals can accumulate significantly in the seaweed family. The levels of these substances in consumed kelp sources need to be recognized and controlled to prevent harmful effects for you.

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