Health Benefits of Kelp: The Ultimate Guide

Kelp, scientifically known as Ascophyllum nodosum, is a type of brown seaweed that has gained attention for its potential health benefits. This article aims to provide you with a comprehensive guide on the various health benefits associated with kelp consumption. From its rich composition to its impact on neurology, cardiovascular health, longevity, metabolism, fat mass, inflammation, and oxidation, kelp offers a wide range of potential advantages for overall well-being.

What is Kelp?

Kelp, scientifically known as laminaria, is a type of leafy algae that thrives in nutrient-rich saltwater near coastal areas worldwide. Its rapid growth rate sets it apart, with some species, such as giant kelp, growing up to 300 feet (100 meters) in a single year. Kelp requires sunlight and a hard surface to attach to as it grows. It is an abundant source of iodine, an essential component for thyroid hormone production. This is particularly important for vegans who don't really get iodine from many other sources.

Where Is Kelp From?

Kelp is a seaweed that grows in the mild intertidal zones of North Atlantic temperate rocky shores. It can be found along the coasts of France, European countries, and Atlantic Canada. Ascophyllum nodosum, also known as rockweed, is a species of brown seaweed that falls under the blanket term of rockweed. It is characterized by its high phlorotannin content, making it unique among seaweeds.

The composition of kelp is noteworthy. It contains sulfated polysaccharide chains called fucoidans, which we'll come back to when we explore their health benefits. Kelp also contains a specific sulfated polysaccharide known as Ascophyllan, with a molecular size of 390kDa. Other components found in kelp include myristic acid, palmitic acid, stearic acid, omega-6 fatty acids, fish oil fatty acid EPA, medium-chain fatty acid butyric acid, phlorotannins, phenolics, quaternary ammonium compounds, iodine, vanadium, fucosterol, minerals, and fatty acids.

Kelp And Weight Loss

Studies have shown that the addition of Ascophyllum nodosum to whole wheat bread can influence caloric intake. When individuals consumed bread enriched with 4% Ascophyllum nodosum, they experienced a 16.4% reduction in caloric intake at the subsequent meal. However, no significant changes in self-reported sensation of fullness or satiety were observed.

The mechanisms behind the appetite-reducing effects of Ascophyllum nodosum are still unknown and require further investigation.

With its low fat and calorie content, kelp can be a valuable addition to a weight management plan. It contains a natural fiber called alginate, which has been shown to inhibit fat absorption in the gut. Research suggests that alginate can block the activity of lipase, an enzyme responsible for digesting fat. Additionally, studies indicate that kelp may influence glycemic management and help lower blood glucose levels, which could be beneficial for individuals with type 2 diabetes.

Research has shown that Ascophyllum nodosum can inhibit α-glucosidase, an enzyme involved in carbohydrate digestion. An aqueous ethanolic extract of Ascophyllum nodosum inhibited α-glucosidase with an IC50 of 77ug/mL. Increasing the polyphenolic content of the extract improved its inhibitory effect.

These inhibitory effects on carbohydrate absorption enzymes are likely due to the polyphenolic content of Ascophyllum nodosum. However, there is some variance in the results, and more studies are needed to fully understand the inhibitory action of Ascophyllum nodosum on carbohydrate absorption.

Animal studies have demonstrated the potential anti-obesity effects of Ascophyllum nodosum supplementation. Rats fed a high-fat diet and supplemented with Ascophyllum nodosum experienced reduced weight gain and decreased body fat percentage compared to the control group.

These results suggest that Ascophyllum nodosum may have potential anti-obesity effects, although further research is needed to confirm these findings and understand the underlying mechanisms.

Cardiovascular Health

In vitro studies have suggested that kelp may have lipase (fat) inhibitory potential. When incubated with ID-aIG™, a combination of Ascophyllum nodosum and grape seed extract, lipase activity was inhibited by 71.0 +/-2.0%. In animal studies, supplementation with ID-aIG™ reduced triglyceride levels by 30.6% and prevented weight gain induced by a high-fat diet.

Further research is needed to fully understand the absorption-related benefits of Ascophyllum nodosum and its potential implications for cardiovascular healthand weight loss.

Does Kelp Help Blood Clotting

Fucoidans derived from Ascophyllum nodosum have been found to possess anti-coagulant properties. However, they do not exhibit significant antithrombin activities.

While the practical significance of these findings is still unknown, Ascophyllum nodosum may have potential anti-clotting properties that warrant further investigation.

Longevity and Life Extension

Studies have shown that an extract of Ascophyllum nodosum, rich in phlorotannins, can activate SIRT1, a protein associated with longevity and aging. This extract was able to activate SIRT1 to levels higher than those achieved by resveratrol, a compound often associated with longevity.

These findings suggest that kelp may have the potential to enhance longevity and life extension, although further research is needed to confirm these effects and understand the underlying mechanisms.

Kelp And Inflammation

Studies have shown that an extract of kelp can release pro-inflammatory cytokines, such as TNF-α. Fucoidans, a compound from Ascophyllum nodosum also possess anti-inflammatory properties. However, these properties are not significantly better than those observed in fucoidans from other seaweeds.

While these findings suggest that Ascophyllum nodosum may have anti-inflammatory effects, further research is needed to fully understand its immunomodulatory properties.


Kelp's high antioxidant content, including carotenoids and flavonoids, makes it a potential ally in the fight against chronic diseases. Antioxidants help combat free radicals, which contribute to inflammation and oxidative stress in the body. Studies have explored the role of kelp in estrogen-related and colon cancers, osteoarthritis, and other conditions. While promising, more research is needed to substantiate these claims fully.

Injection of Ascophyllum nodosum polysaccharide Ascophyllan in mice has been found to increase natural killer (NK) cell activity. Ascophyllan appears to stimulate NADPH oxidase and enhance phagocytosis in macrophages. These immunostimulatory actions make Ascophyllan a promising compound for further investigation.

Is Kelp An Anti Inflammatory?

Kelp, specifically the phlorotannins found in Ascophyllum nodosum, has been found to possess potent antioxidant properties. These phlorotannins demonstrate high antioxidant potential on in vitro tests, comparable to well-known antioxidants like quercetin and trolox.

In cellular experiments, Ascophyllum nodosum extracts have shown the ability to prevent oxidative damage induced by tBHP (tert-butyl hydroperoxide). However, the effects of Ascophyllum nodosum extracts at higher concentrations require further investigation.

These antioxidant properties suggest that Ascophyllum nodosum may have the potential to protect against oxidative stress and its associated health risks.

Kelp Side Effects

While kelp offers many health benefits, it is essential to exercise caution and be aware of potential side effects. The high iodine content in kelp can have adverse effects on thyroid function. Excessive iodine intake can lead to both hypothyroidism and hyperthyroidism, exacerbating existing thyroid conditions. Additionally, kelp may contain harmful metals, including cadmium, lead, and aluminum, especially if sourced from contaminated ocean waters. Pregnant or breastfeeding women should avoid kelp supplements, and individuals with thyroid issues or those taking certain heart medications should consult their healthcare provider before using kelp.

Health Benefits of Kelp Conclusion

Kelp, specifically Ascophyllum nodosum, offers a wide range of potential health benefits. From its potential effects on appetite, cardiovascular health, longevity, glucose metabolism, fat mass, inflammation, and oxidation, kelp is a seaweed with promising properties. However, further research is needed to fully understand the mechanisms behind these effects and to determine proper dosages for optimal benefits.

Incorporating kelp into your diet may be a valuable addition to promote overall well-being. As always, it is recommended to consult with a healthcare professional before making any significant changes to your diet or supplementation routine.

Remember, kelp supplements are not intended to diagnose, treat, cure, or prevent any disease or condition. They should be used as part of a healthy lifestyle and in conjunction with proper medical advice.

Popular Posts

Best Sleep Aids

Find out about the best natural sleep aids on the market.

learn more

Best Greens Powders

Not all greens powders are made equal. In fact a lot are pretty worthless, don't waste your money and get the best.

learn more

Best Joint Supplements

Looking for a joint supplement? Not sure what's actually good, we've got you covered.

learn more