The ocean is an abundant source of nutrient-rich foods, not the least of which are seaweeds.
Among these seaweeds, sea kelp is very intriguing due to its wide range of potential benefits and applications in food and medicine.
In this article, we will look at the health benefits of kelp, its safety, its history, and how to incorporate it into the diet.
Table of Contents
What is Kelp?
Sea kelp is a general term referring to many different types of brown seaweeds that make up the order Laminariales.
Some of the top varietals of sea kelp include:
- Laminaria japonica (Kombu)
- Laminaria digitata (Oarweed)
- Laminaria saccharina (Sugar Kelp)
- Macrocystis pyrifera (Giant Kelp)
- Nereocystis luetkeana (Bull-Head Kelp)
Kelp generally thrives in colder-to-temperate waters (42-72 degrees F) and can usually be found in shallow areas close to shore. They are abundant along the Pacific coast from Alaska all the way down to southern California, but can also be found on the Atlantic coastline.
Like other seaweeds, varieties of sea kelp are rich in numerous nutrients, including fiber, vitamins, minerals, and antioxidants.
Some of the specific nutrients found in sea kelp include:
- Soluble fibers, such as alginates, laminarin, and fucoidan
- Fucoxanthin and fucosterol
- Magnesium
- Omega-3 fatty acids
- Iron
- Iodine
- Calcium
- Zinc
- Vitamins A, B (B1, B2, B6, B9, B12), and K
Health Benefits of Kelp:
Due to its nutrient content, there are a number of potential health benefits of sea kelp.
Additionally, sea kelp varieties appear to have some of the most clinical research behind them, which makes them more applicable to human health.
All in all, sea kelp benefits the following aspects of human health.
1. May Help with Weight Loss
In this day and age, weight loss is a top priority for many people. Intriguingly, sea kelp benefits weight loss through a number of effects on metabolism, gut health, and other factors.
One study looked into the effects of Laminaria japonica extract supplementation in 22 female college students. After 8 weeks, they found that supplementation led to improved body composition, nutrient intake, and quality of life.
In another study, supplementation with iodine-reduced kelp powder in 50 overweight men led to significant reductions in body fat, body weight, and body mass index (BMI).
Another human study found that supplementing with fucoxanthin extract from kelp led to reductions in body weight, BMI, and abdominal fat. Fucoxanthin is a carotenoid compound, a type of antioxidant, found in a number of brown seaweeds The researchers concluded that fucoxanthin was able to decrease both visceral and subcutaneous body fat.
Finally, one study done on mice found that a polysaccharide-rich Laminaria japonica extract led to significant reductions in weight gain and fat accumulation. Moreover, this extract improved serum lipid profiles, decreased intestinal damage, and had favorable effects on fat metabolism.
Summary:
Studies indicate that sea kelp may be beneficial in reducing body weight.
2. May Help With Blood Sugar Stabilization
Emerging evidence shows that sea kelp benefits insulin activity and metabolic health, which could have implications for diabetes and other metabolic disorders.
In a placebo-controlled clinical study involving 25 overweight individuals, supplementing with fucoidan extract from sea kelp led to significantly lower LDL cholesterol and blood pressure compared to placebo.
Also, in a 3-way, blinded, crossover human clinical trial, supplementing with brown seaweed was associated with lower glucose, insulin, and C-peptide response compared to placebo. The seaweed groups also showed better appetite control compared to the placebo.
In another study in high-fat-diet-fed mice, a sea kelp extract was associated with reductions in insulin resistance, inflammation, gut permeability, and gut dysbiosis. Overall, the beneficial metabolic effects were attributed to improved gut health.
Summary:
Sea kelp has been shown to have properties that assist in improving insulin activity and metabolism.
3. Antioxidant Properties
Another potential health benefit of sea kelp is its antioxidant and anti-inflammatory properties.
In a placebo-controlled clinical study, researchers looked into the effects of a fermented sea kelp extract on antioxidant levels in 48 people with high gamma-glutamyl transferase (GGT) (a marker of possible liver damage). They found that supplementing with this extract led to a significant reduction in GGT alongside significant increases in superoxide dismutase and other antioxidants compared to placebo.
Another study discovered that fucoidan extracted from brown seaweed possesses significant antioxidant and anticoagulant properties, and thus may play a role in cardiovascular health as well.
An additional study done in mice found that an extract from Laminaria digitata had protective effects against certain markers of aging. Specifically, compared to controls, mice who received the extract had lower levels of inflammation (e.g. IL-6) in the brain and liver, higher skin collagen content, and lower fat levels, suggesting antioxidant and anti-aging effects.
Lastly, another study looked into the protective effects of an extract from Laminaria digitata after inducing skin cancer in mice. It was found that, compared to controls, mice fed the sea kelp extract had healthier levels of keratin, better skin health, and better liver and heart function.
Summary:
Several studies show that sea kelp has the ability to increase antioxidant levels in the body.
4. May Improve Gut Health
It is also likely that sea kelp benefits gut health due to its many gut-supportive compounds, including alginate and fucoidan, among others.
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