Kelp is one of the brown seaweeds . Ascophyllum nodosum is a brown seaweed...
...that grows abundantly in the US Northeast coastal region.
Nutrition Values and Potential Uses
it is also a source of iodine, potassium, magnesium, calcium and iron. Some people use kelp as iodine supplements for hypothyroidism. Thyroid
hormones are important to maintain normal cell metabolism. Some marketers suggest kelp may help improve metabolism, regardless the limited
evidence for such benefit claim. It is one of the major ingredient in a commercial homeopathic product - ANTI AGE SKIN (Guna Inc). This product is
claimed for the temporary relief of general skin aging symptoms due to environmental exposure to wind, sun and pollution such as: excess wrinkles
and dry leathery skin. [NOTE 1]
Kelp Ascophyllum nodosum is also used as a source of iodine. Iodine, a nonmetallic element of the halogen group, is represented by the atomic
symbol I, atomic number 53, and atomic weight of 126.90. Iodine is important in thyroid hormone synthesis. Iodine also has anti-infective properties
and is used topically. [A1] Iodine is likely effective for iodine deficiency, radiation exposure (against exposure to radioactive iodides) and thyroid
conditions. Intake of Kelp Ascophyllum nodosum may benefit people suffered from fibrous breast tissue, soreness and swelling inside the mouth
(because of chemotherapy) and foot ulcers (associated with diabetes). [A2] Consequently kelp Ascophyllum nodosum is used as supplements and it
sold in the forms of powder, capsules and tablets.
Related Names: Atlantic Kelp; Kelp (Ascophyllum nodosum) (Algae); Kelp (Laminaria digitata); Source of Iodine; Kelp; Potassium Iodide (Source
of); Bladderwrack; Fucus; Rockweed; Dulse; Red Seaweed; Brown Kelp; Red Kelp; Laminaria; Thallus
Potential Uses and Health Benefits of Kelp
People avoiding sea foods may develop iodine deficiency. Iodine deficiency can lead to low thyroid function
(hypothyroidism), goiter etc. Epidemiological studies suggest that populations consuming typical Asian diets have a
lower incidence of hormone-dependent cancers than populations consuming Western diets. These dietary differences
have been mainly attributed to higher soy intakes among Asians. However, studies of rats and cells from UC Berkeley
suggest that the anti-estrogenic effects of dietary kelp also may contribute to these reduced cancer rates.  Japanese
researchers even claim kelp in Japanese has prolonging effect of on life span in mice, even though they are fed with
diet containing carcinogen.  Ascophyllum nodosum has phenolic contents and subsequent antioxidant, α-
glucosidase and α-amylase inhibitory activities. [B2] Thus, Kelp Ascophyllum nodosum is expected to offer a variety of
Health Benefits of Kelp Ascophyllum nodosum - Research Findings
In a study, an unfractionated fucoidan was extracted from the brown alga Ascophyllum nodosum. This fucoidan of the
kelp Ascophyllum nodosum decreased cell viability and induced apoptosis of HCT116 colon carcinoma cells. Fucoidan
treatment of HCT116 cells induced activation of caspases-9 and -3 and the cleavage of PARP, led to apoptotic
morphological changes, and altered mitochondrial membrane permeability. [B1] Thus, kelp may benefit people at risk
of certain cancers but more studies are needed to confirm this health benefit-claim.
A study indicate that 2% a Kelp Ascophyllum nodosum supplementation in feedlot cattle diets reduces Escherichia coli
O157 and Escherichia coli O157:H7 prevalence on hide swabs and in fecal samples and may suppress increases in
Salmonella spp. Kelp Ascophyllum nodosum may have some benefits against certain infections, but more studies are
needed to support the claim. [C1]
Sugar Level (Diabetes)
In a study of 23 subjects, subjects consumed a commercially available blend of brown seaweed (Ascophyllum nodosum
and Fucus vesiculosus), 500 mg on each occasion 30 min prior to the consumption of 50 g of carbohydrates from
bread.Compared with placebo, consumption of seaweed was associated with a 12.1% reduction in the insulin
incremental area under the curve and a 7.9% increase in the Cederholm index of insulin sensitivity. The single
ingestion of 500 mg of brown seaweed had no significant effect on the glucose response. Glucose and insulin
responses were similar between men and women. Consumption of the brown seaweed capsules was not associated
with any adverse event. These data suggest that brown seaweed may alter the insulin homeostasis in response to
carbohydrate ingestion, thus, may benefit people at risk of diabetes. But, more studies are needed to confirm the
Weight Loss / Management
Kelp Ascophyllum nodosum may have a potential health benefit for people under weight control. Further, Kelp
Ascophyllum nodosum may also benefit people at high triglyceride. It is well recognised that the consumption of
seaweed isolates (such as alginate) successfully reduce energy intake and modulate glycaemic and cholesterolaemic
responses. In a study of Sprague-Dawley rats, a seaweed extract of Kelp Ascophyllum nodosum, ID-alG™ was orally
administered daily during 9 weeks at doses of 40 and 400 mg/kg/day of with fat-enriched diet (FED) in comparison with
two control groups consuming standard diet (negative control) or FED (positive control) and orally treated with vehicle.
After 9 weeks, the oral administration of the Kelp Ascophyllum nodosum extract at both doses decreased significantly
the mean body weight gains (MBWG) of rats submitted to the FED in comparison to the positive control (-6.8% and
-11.8%). Kelp Ascophyllum nodosum extract at both doses improved significantly the MBWG of rats and decreased
significantly the percentage of body fat mass of rats (-9.8% and -19.0%), in comparison to the positive control. In the
same way, the triglyceride blood level was also significantly improved for the dose of 400 mg/kg/day. [A5] In another
single trial but with human (n=12 males, aged 40.1 year; BMI 30.8 kg/m(2)) was used to compare energy intake and
nutrient uptake after a breakfast meal using the enriched bread (4% Kelp Ascophyllum nodosum) against the control
bread (0% A. nodosum). Consumption of the enriched bread at breakfast led to a significant reduction (16.4%) in
energy intake at a test meal 4h later. [A3] Thus, Kelp Ascophyllum nodosum may be useful in weight management
programs, but more studies are needed to confirm the research findings.
KELP SIDE EFFECTS, WARNING AND SAFETY
POTENTIAL SIDE EFECTS OF IODINE, KELP (ASCOPHYLLUM NODOSUM) (ALGAE)
Iodine is likely safe for most healthy people at recommended dosages. However, intake of large amount can cause
significant side effects in some people. According to MedlinePlus Supplements, intake of iodine can cause side effects
such as nausea, stomach pain, runny nose, headache, metallic taste, and diarrhea. Intake may also cause side effects
including lip and face swelling, bleeding and bruising, fever, joint pain, lymph node enlargement in sensitive people.
You must stop taking iodine, once you experience the side effects.
Intake of more than 2000 mcg of kelp a day may also lead to interference of normal thyroid functions and other harmful
side effects. [1-6] A 39-year-old woman with multinodular goiter presented with typical signs of hyperthyroidism. She
had been treated for a period of 4 weeks with a herbal tea containing kelp, she developed hyperthyroidism. 
People with autoimmune thyroid disease, dermatitis herpetiformis, or any thyroid disorders must discuss with their
doctors before taking iodine.
References 1. Wolff J. Iodide goiter and the pharmacologic effects of excess iodide. Am J Med 1969;47:101Â–24. 2.
Shilo S, Hirsch HJ. Iodine-induced hyperthyroidism in a patient with a normal thyroid gland. Postgrad Med J 1986;62:
661Â–2. 3. Ishizuki Y, Yamauchi K, Miura Y. [Transient thyrotoxicosis induced by Japanese kombu]. Nippon Naibunpi
Gakkai Zasshi 1989;65:91Â–8 [in Japanese]. 4. Hartman AA. [Hyperthyroidism during administration of kelp tablets
(letter)]. Ned Tijdschr Geneeskd 1990;134:1373 [in Dutch]. 5. de Smet PA, Stricker BH, Wilderink F, Wiersinga WM.
[Hyperthyroidism during treatment with kelp tablets]. Ned Tijdschr Geneeskd 1990;134:1058Â–9 [in Dutch]. 6. Eliason
BC. Transient hyperthyroidism in a patient taking dietary supplements containing kelp. J Am Board Fam Pract 1998;11:
478Â–80.  Mussig K, Thamer C, Bares R, Lipp HP, Haring HU, Gallwitz B.Iodine-induced thyrotoxicosis after ingestion
of kelp-containing tea. J Gen Intern Med. 2006 Jun;21(6):C11-4.  Skibola CF, Curry JD, VandeVoort C, Conley A,
Smith MT. Brown kelp modulates endocrine hormones in female sprague-dawley rats and in human luteinized
granulosa cells. J Nutr. 2005 Feb;135(2):296-300.  Sakakibara H, Nakagawa S, Wakameda H, Nakagiri Y, Kamata K,
Das SK, Tsuji T, Kanazawa K. Effects of Japanese kelp (kombu) on life span of benzo[a]pyrene-fed mice. J Nutr Sci
Vitaminol (Tokyo). 2005 Oct;51(5):369-73. A1 Dietarysupplements.nlm.nih.gov, December 20, 2011 A2 www.nlm.nih.
gov Medlineplus, December 20, 2011 A3 Hall AC, et al, Ascophyllum nodosum enriched bread reduces subsequent
energy intake with no effect on post-prandial glucose and cholesterol in healthy, overweight males. A pilot study.
Appetite. 2011 Nov 7;58(1):379-386. A4 Paradis ME, et al, A randomised crossover placebo-controlled trial
investigating the effect of brown seaweed (Ascophyllum nodosum and Fucus vesiculosus) on postchallenge plasma
glucose and insulin levels in men and women. Appl Physiol Nutr Metab. 2011 Dec;36(6):913-9. A5 Terpend K, et al,
Effects of ID-alG(™) on Weight Management and Body Fat Mass in High-Fat-Fed Rats. Phytother Res. 2011 Oct 28.
doi: 10.1002/ptr.3619 B1 Foley SA, et al, An unfractionated fucoidan from Ascophyllum nodosum: extraction,
characterization, and apoptotic effects in vitro. J Nat Prod. 2011 Sep 23;74(9):1851-61. B2 Apostolidis E, et al,
Seasonal Variation of Phenolic Antioxidant-mediated α-glucosidase Inhibition of Ascophyllum nodosum. Plant Foods
Hum Nutr. 2011 Nov;66(4):313-9. C1 Braden KW, et al, Ascophyllum nodosum supplementation: a preharvest
intervention for reducing Escherichia coli O157:H7 and Salmonella spp. in feedlot steers. J Food Prot. 2004 Sep;67(9):