Kelp by Ray Sahelian, M.D. Kelp supplement benefit and side effects

Kelp are large seaweeds. Kelps vary widely in size and form. One type of kelp, called giant kelp, may have hundreds of branches, each of which has hundreds of leaves. Giant kelp may reach over 200 feet in length and will create entire forests of kelp. Despite their appearance sea kelp are not grouped with the normal aquatic or land plants (kingdom Plantae), but instead are included in either kingdom Protista or Chromista. Kelp grows in underwater forests ( kelp forests ) in clear, shallow, oceans, requiring nutrient rich water below about 20°C, Sea kelp offer protection to some sea creatures, or food for others. Kelp is known for its high growth rate.  Kelp is a popular food in some cultures, such as the Japanese. Kelp has been promoted as a weight loss supplement, but, in my opinion, Diet Rx works very weel as an appetite suppressant.

Sea Kelp benefit

Kelp is a sea vegetable and a good source of minerals, including iodine, potassium, magnesium, calcium, and iron. The health benefit of kelp may occur in individuals who have an underactive thyroid gland due to iodine deficiency. However, iodine deficiency is not common in Western countries.

Kelp supplement - who needs kelp?
Kelp is a healthy sea vegetable to include in one's diet, but as with any other food, moderation is suggested. A kelp supplement may be used occasionally, but I prefer alternating different supplements rather than taking one supplement in a high dose on a continual basis. Some types of sea kelp, such as bladderwrack, laminaria, and rockweed, are harvested and developed into dietary supplements. If you do plan to take a kelp supplement, take only one or two tablets a day, and take 2 days off a week and a week off each month.

Kelp meal

Kelp Meal is brown seaweed harvested from the cold waters of the north Atlantic Ocean.

Kelp powder

Soluble Kelp Powder is a dehydrated liquid extract from the kelp Ascophyllum nodosom, which is harvested on the Maine coast.

Kelp thyroid gland

Sea kelp as a source of iodine assists in making thyroid hormones, which are necessary for maintaining normal metabolism in all cells of the body. Since the introduction of iodized salt, additional sources of iodine, such as kelp, are not necessary for most people.

Kelp Research

Effects of kelp supplementation on thyroid function in euthyroid subjects.
Endocr Pract. 2003 Sep-Oct;9(5):363-9. Clark CD, Bassett B, Burge MR.
Department of Internal Medicine, Division of Endocrinology and Metabolism, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
To study the effects of ingestion of two different doses of supplemental kelp on the thyroid function of healthy euthyroid subjects. We conducted a double-blind prospective clinical trial involving 36 healthy euthyroid subjects, who were randomly assigned to receive placebo (4 alfalfa capsules per day), low-dose kelp (2 kelp capsules and 2 alfalfa capsules per day), or high-dose kelp (4 kelp capsules per day) for 4 weeks. Thyrotropin (thyroid-stimulating hormone or TSH), free thyroxine, and total triiodothyronine were assessed at weeks 0, 4, and 6. TSH concentrations did not differ significantly between week 0 and week 4 in the placebo group but increased significantly in both the low-dose kelp and high-dose kelp groups. Free thyroxine concentrations decreased slightly but significantly after 4 weeks of placebo but were unchanged in the low-dose and the high-dose kelp groups. In contrast, total triiodothyronine levels did not differ significantly after 4 weeks of placebo or low-dose kelp therapy but were significantly decreased after high-dose kelp therapy. Similarly, the thyrotropin-releasing hormone stimulation test showed no significant change in poststimulation TSH after 4 weeks in the placebo or low-dose kelp groups but revealed a significantly increased response after high-dose kelp therapy. The 24-hour urinary iodine excretion showed dose-dependent increases in the two kelp study groups. Basal metabolic rate did not change significantly in any study group during the 4-week study period. All thyroid laboratory values returned to baseline 2 weeks after cessation of kelp supplementation, except for TSH in the high-dose kelp group, which was significantly decreased. CONCLUSION: Short-term dietary supplementation with kelp significantly increases both basal and poststimulation TSH. These findings corroborate previous studies on the effects of supplemental iodide given to euthyroid subjects for a similar period. Further studies are needed to determine whether long-term kelp supplementation would cause clinically significant thyroid disease.

Kelp Benefit questions

Q. I was looking for information on kelp benefit and came across a website that was claiming this: "The electrolytic magnetic action of the sea plants releases excess body fluids from congested cells and dissolves fatty wastes through the skin, replacing them with depleted minerals, particularly potassium and iodine. Sea Vegetables (Spirulina - Kelp - Chlorella) have been acknowledged as a detoxifyer, a balanced nourishment and a miraculous healing plant."
     A. The person who wrote this obviously does not have a medical background and does not seem to have a good understanding of molecular biochemistry. When you see people using the word "detoxify" be on alert.

Q. Part two of my question is a claim I came across another site. "The immediate benefit obtained from kelp can be attributed to the release of auxins, cytokinins and gibberellins. These plant growth hormones, required in small quantities, are essential for cell division and cell elongation, basic functions of plant growth."
     A. Since no long term human studies have been done to determine benefit of kelp, it is premature to make such a kelp benefit claim.

Q. Is Norwegian kelp supplement healthier than sea kelp from other areas?
     A. I have not seen any studies that indicate Norwegian kelp is any better than kelp from other oceans.