10 Health Benefits of Kelp and its Side Effects

kelp benefits

Kelp has been growing at the bottom of our oceans for millions of years. Although this nutritious seaweed is a dietary staple in countries like Japan and Korea, there has been an increased interest in kelp in the US in recent years. Since it is rich in vitamins minerals and amino acids, kelp offers numerous health benefits. It helps in weight loss, keeps bones healthy, reduces the risk of cancers, and supports thyroid health. Let us learn about this nutritious seaweed and its health benefits.

What is kelp?

Kelp is a seaweed that belongs to the brown algae family Laminaiaceae. It grows in shallow, nutrient-rich saltwater, near coastal fronts around the world. There are around 30 varieties of kelp. Giant kelp, sugarwack, southern kelp, and bull kelp are a few different varieties of kelp.

Though kelp may look like a plant, it is actually a form of sea algae. The kelp plant is made up of three parts: the blade (the leaf-like structure), the stipe (the stem-like structure) and the holdfast (the root-like structure). The holdfast grips a substrate and anchors the kelp to keep it secure despite moving waves and currents.

Kelp has been consumed and used medicinally for hundreds of years. People have used kelp ash for years in soap and glass production. Alginate, a kelp-derived carbohydrate, is used to thicken products like toothpaste, jelly, and ice-cream. Alginate powder is also used in dentistry.

The nutritional profile of kelp

Kelp is highly nutritious, with few calories and very little fat. It is one of the highest known sources of minerals. One serving (28 grams) of raw kelp contains (1) –

  • Calories: 12
  • Carbohydrate: 2.7 gram
  • Fat: .2 gram
  • Protein: .5 gram
  • Dietary fiber: .4 gram
  • Vitamin K: 18.3 micrograms (23% DV)
  • Folate: 50.4 micrograms (13% DV)
  • Magnesium: 33.9 milligrams (8% DV)
  • Calcium: 47 milligrams (5% DV)
  • Iron: .8 milligram (4% DV)
  • Manganese: .1 milligram (3% DV)

History of kelp

People have eaten different varieties of kelp for their nutritional value all around the world for thousands of years. The Chinese used kelp and other seaweeds for their medicinal value since 3000 BC. The Greeks fed kelp to their cattle around the first century BC. Icelanders too have eaten kelp for centuries. The ancient Hawaiian nobles grew gardens of edible seaweed. Kelp was also used in Europe and Great Britain as a fertilizer.

Japan, however, has been the largest consumer of kelp. The Japanese have used kelp in their diet for the last 1500 years. During the seventh and the ninth centuries, only the nobility consumed seaweed. The Japanese started farming seaweed in the seventeenth century. They used kelp to treat prostate kidney and bladder ailments, uterine problems, and genital tract disorders. The Japanese include kelp in every meal, using it in salads, soups, sauces, and cakes.

Health benefits of kelp

1. Rich in iodine

Kelp is amongst the best natural sources of iodine. Iodine is a vital nutrient, which is essential for thyroid hormone production. A deficiency in iodine can cause goiter, an enlargement of the thyroid gland or metabolism disruption, which could lead to weight changes and high cholesterol. Powdered kelp has even been used to treat hypothyroidism in patients with severe motor intellectual disabilities (2).

2. Helps fight cancer

Kelp helps slow the spread of colon and breast cancer. It can also mitigate the spread of lung and prostate cancer thanks to fucoidan, a natural compound found in kelp. Several studies have shown that fucoidan induces apoptosis (cancer cell death) in colorectal cancer, breast cancer, leukemia, and lung cancer (3, 4, 5).

Fucoxanthin, a marine carotenoid found in kelp, also displays anti-cancer activity against prostate cancer cells. Fucoxanthin also removes drug resistance in cancer patients that are undergoing chemotherapy treatment (6).

3. Prevents and treats diabetes

Kelp may also be beneficial for people with type 2 diabetes as it influences glycemic control, lowers blood lipids, and increases antioxidant enzyme activities. During a study, 20 patients with type 2 diabetes took powdered seaweed pills for four weeks. The results showed a decrease in fasting and post-meal blood sugar levels and serum lipid levels. The pills also increased DHL levels, which prevents heart disease associated with diabetes (7).

Kelp also contains vanadium, which has been used in clinical studies to lower glucose levels in people with diabetes. During a 2013 study, 14 patients with type 1 diabetes were given oral vanadyl sulfate (50 to 100 mg daily) for 30 months. The results showed a 30 % decrease in fasting blood sugar levels. Vanadium also decreased cholesterol levels (8).

4. Helps in weight loss

Fucoxanthin, a carotenoid found in kelp, has strong anti-obesity properties. According to a study from Japan, fucoxanthin helps remove white adipose tissues, which help in reducing weight (9). During one study when xanthigen(brown marine algae fucoxanthin and pomegranate seed oil) was given to female volunteers for 16 weeks, it promoted weight loss, reduced body, and liver fat content, and improved liver function test (10).

Kelp also contains alginates which can help in fat loss. According to a study, alginates reduce the activity of a protein in the pancreas that breaks down fats. Lower activity reduces fat breakdown, which leads to fewer fats being absorbed after meals (11).

5. Fights inflammation

Inflammation is considered the root of many ailments, which is why it is essential to include anti-inflammatory foods in your diet. Certain types of kelp have potent anti-inflammatory activity, which is why they are considered as a useful therapeutic and preventive approach to various inflammatory and oxidative-stress-related diseases (12).

A study from Capital Medical University, Beijing, studied the effect of fucoidan (present in kelp) on inflammation-mediated dopaminergic neuronal damage. The study found that fucoidan significantly improved the behavioral manifestation, reduced harmful compounds, prevented neuron loss, and protected the cells from damage (13).

6. Improves blood flow

Fucoidan, a nutrient found in kelp, help deal with many blood-related disorders. It helps in preventing blood clots, which can lead to stroke and heart attacks. According to a study from china, low molecular weight fucoidan has the potential to become an oral antithrombotic agent (14).

A study from the University of Manitoba, Canada, studied the effects of fucoidan treatment on collagenase-induced intracerebral hemorrhage in rats. They found that fucoidan infusion decreased clotting in bleeding rats. The rats also had less swelling and better memory retention after the treatment (15). Since fucoidan improves blood flow, it protects the body from ischemic damage (16).

7. Improves bone health

Kelp is rich in vitamin K, which is essential for bone health. Vitamin K increases bone strength and decreases the risk of fractures in people who have osteoporosis. It also slows down bone loss in women after menopause. Fucoidan present in kelp also boost the development osteoblasts, the cells that build bones. It also increases the growth of new vessels, improving communication with bones (17).

8. Boosts brain health

Kelp is one of the best natural sources of iodine. Iodine is an essential nutrient for the growth and development of the brain. Iodine deficiency can lead to mental impairment. Iodine is also vital for thyroid hormone production. Maintaining the right amount of thyroid hormone ensures the blood-brain barrier is working and prevents brain fog. According to a recent study, seaweed extracts helped protect brain cells from death in cell models of Parkinson’s disease (18).

9. Protects against heart disease

Kelp is rich in potassium, which has a significant effect on heart health. It helps to lower blood pressure and balance out the adverse effects of salt. Fucoidan, a compound found in kelp, has the same effect as blood-thinning medications and helps avoid blood clots. The antioxidants found in kelp also help prevent oxidative stress, which prevents heart disease.

According to a 2017 study from Japan, fucoidan can alleviate high-fat diet-induced dyslipidemia and atherosclerosis in mice (19).

10. May treat herpes

Fucoidan, a sulfated polysaccharide isolated from kelp, is known to inhibit the herpes simplex virus. According to a 2008 study from the University of Toyama, Japan, fucoidan blocked the growth of herpes simplex virus type 1 in mice that were infected. The results of this study showed that oral intake of fucoidan inhibits viral replication and stimulates both innate and adaptive immune defense functions (20).

Ways to eat kelp

You can find kelp at most health food stores or in the Asian food section of your grocery store. There are several ways to incorporate kelp in your diet.

1. Kelp noodles

If you’re trying to cut back on carbs, kelp noodles are a great option. They work as an excellent substitute for any noodle dish.

2. Kelp soup

Kelp soup is the most common way to eat kelp. Soups made from kelp high on nutrition.

3. Dried kelp

If you can find only dried kelp in your supermarket, reconstitute it with a little water and then drain it. Mix it with some sliced cucumber. Add some sesame oil, Asian vinegar and sprinkle with sesame seeds.

4. Kelp powder

Kelp powder is a convenient way to add some nutrients in your diet. You can add it to smoothies, salad dressing and even make kelp tea with it.

Kelp side effects

Always consult with your doctor before taking kelp supplements if you are pregnant, breastfeeding, or suffering from an ailment.

1. Iodine

Kelp is rich in iodine. Although iodine has many health benefits, overconsuming, it can lead to thyroid problems and also thyroid cancer.

2. Heavy metals

Sea kelp that grows in polluted waters can absorb toxic heavy metals such as arsenic, cadmium, and lead. These can be dangerous for health.

3. Different affects

A large number of sea kelp supplements contain different types of algae. These can affect the body in different ways. For example, bladderwrack is known to worsen acne.

Final thoughts

Kelp is a seaweed that belongs to the brown algae family Laminaiaceae. It has been eaten and used medicinally for thousands of years. It is one of the best sources of iodine. Kelp helps to fight cancer, prevents diabetes, helps in weight loss, fights inflammation, improves blood flow, and is beneficial for bone and heart health.

You can eat kelp in the form of noodles, soup, add it to salads and even consume kelp supplements. Taking too much kelp can lead to excessive intake of iodine, which is harmful to health. Kelp growing in polluted water contains toxic metals which are bad for health.

Manveen had an illustrious career in journalism and writing. She is the mother of a super active 7-year-old. While chasing her around the house, she also finds time to pursue her passion for writing on parenting, education, health, fitness, and entertainment.