Brown Seaweed (wakame) Health Benefits and Side Effects   August 16, 2013
brown seaweed, wakame, Brown kelp, Undaria pinnatifida
Brown Seaweed Health Benefits

Abdominal Fat
Brown seaweed may offer benefits to people with high abdominal fat. Mitochondrial uncoupling protein 1 (UCP1) is
usually expressed only in brown adipose tissue (BAT) and a key molecule for metabolic thermogenesis to avoid an
excess of fat accumulation. However, there is little BAT in adult humans. Therefore, UCP1 expression in tissues other
than BAT is expected to reduce abdominal fat. In a study, Dr. Kazuo Miyashita from Hokkaido University show reduction
of abdominal white adipose tissue (WAT) weights in rats and mice by feeding lipids from edible brown seaweed (or
brown kelp). [3]

Acne vulgaris
Acne vulgaris (or acne) is a skin disease, characterized by areas of skin with seborrhea (scaly red skin), comedones
(blackheads and whiteheads), papules (pinheads), nodules (large papules), pimples, and possibly scarring. A study
suggests brown seaweed may benefit people at risk of acne, as seaweed oligosaccharide-zinc complex
(Phycosaccharide AC, The Mentholatum Company, East Kilbride, UK) and other seaweed oligosaccharides ameliorated
symptoms of acne vulgaris, particularly in terms of reducing sebum production and populations in a study. [A9]

Brown seaweed extracts showed benefits in cancer in a study of mice. Studies suggested the brown seaweed health
benefits on cancer. Fucoidans, fucose-enriched sulfated polysaccharides isolated from brown algae and marine
invertebrates, have been shown to exert anticancer activity in several types of human cancer, including leukemia and
breast cancer and in lung adenocarcinoma cells, as well as hepatocellular carcinoma SMMC-7721 cells.  Researchers
have shown that the fucoidan isolated from brown seaweed - Undaria pinnatifida induced apoptosis in SMMC-7721
cells via the ROS-mediated mitochondrial pathway.[A8] Flucoxanthin helps promote the death of human prostate
cancer cells in culture. Researchers showed that fucoidan, extracted from dietary seaweed, could inhibit tumor growth
in a mice study. In the study, fucoidan significantly enhanced the cytolytic activity of NK cells and increased the amount
of IFN-gamma produced by T cells up to about 2-fold compared with non-treated mice. [T1] Thus, intake of seaweed
extract supplements may benefit people at risk of certain cancers.

Heart Disease and Diabetes
Fucoxanthin induces expression of the fat-burning protein UCP1 that accumulates in fat tissue around the internal
organs and adipose tissue responsible for the thickening of the girth dubbed "middle-age spread". Research has
shown that excess amounts of fat around the midriff are particularly linked to heart disease and diabetes.  UCP1 fuels
the oxidation of fatty acids and production of heat energy in fat tissue mitochondria. Mice fed fucoxanthin showed clear
signs of UCP1 expression in fat tissue, compared to controls. [1-3] Thus, brown seaweed may benefit people at risk of
certain heart conditions and diabetes.

Is there other mechanism for brown seaweed's anti-diabetic effects - sugar control? Yes, researchers found that
extracts of seaweeds have α-amylase inhibitory effect, while Ascophyllum nodosum had the strongest α-amylase
inhibitory effect. [A7] Amylase is an enzyme that catalyses the breakdown of starch into sugars, inhibition of this
enzyme can help prevention glucose absorption. Thus, intake of brown seaweed may benefit people at risk of diabetes.

Hyperlipidemia (High Cholesterol)
Dr. Kazuo Miyashita also found that fucoxanthin has "strong" anti-diabetes effects by promoting the docosahexaenoic
acid (DHA) production in the liver. DHA is an important ingredient in fish oil supplement. It is believed that DHA can help
cut levels of "bad" cholesterol associated with obesity and heart disease. [1,2] A study of rats in 2002 has shown that
simultaneous consumption of fish (fish oil) and brown seaweeds decreases the concentration of triacylglycerol in the
serum and liver. [4] In the study, Dr. Miyashita found no adverse side effects in the animals. Researchers from National
Research Institute of Fisheries Science, Japan, fed rats in different proportions of dried powder of the brown seaweed,
Undaria pinnatifida (wakame). They found that serum and liver triacylglycerol levels in rats fed diets in which wakame
constituted at least 2% were significantly lower than those in rats fed the control diet after the 21-d feeding period. [A3]
Thus, the brown seaweed, (or the brown kelp) may benefit people at risk of high cholesterol.

Brown seaweed (brown kelp) may benefit hypertension. Researchers isolated a few tetrapeptides from wakame (brown
seaweed, Undaria pinnatifida) and determined their blood-pressure lowering activities in hypertensive rats. They noted
the blood pressure significantly decreased after tetrapeptide ingestion. [A1] In other studies, researchers identified
angiotensin I-converting enzyme (ACE) inhibitory peptides. Among these peptides, Val-Tyr, Ile-Tyr, Phe-Tyr, Tyr-His,
Lys-Tyr, and Ile-Trp, decreased the blood pressure significantly in spontaneously hypertensive rats. [A2, A4]

Japanese researchers further suggest that brown seaweed (wakame) may have a beneficial effect on cerebrovascular
diseases in stroke-prone spontaneously hypertensive rats, independent of hypertension. It is possible that fucoxanthin
in Wakame may have a preventive effect against ischaemic neuronal cell death seen in stroke-prone spontaneously
hypertensive rats with stroke. [A5]

Brown seaweed (or the brown kelp) may benefit Herpes infections. Herpes simplex virus type 1 (HSV-1) infections were
found to have low reactivation rates and Herpes type 2 (HSV-2) infections have lower incidence in Japan than in the
west. Australian researchers fed 21 patients with either active or latent Herpetic infections (HSV-1, 2, EBV, Zoster) with
brown seeweed extracts. They found that ingestion of these brown seeweed extracts was associated with increased
healing rates in patients with active infections. It is interesting to know if the benefit of this extract can be extended to
other infections. [I1] The major component of an aqueous extract of the brown seaweed Undaria pinnati fi da has been
identified previously as a galactofucan (GFS), a sulfated polysaccharide. Researchers from The University of Chicago
showed that the mode of action of the GFS against herpes simplex virus to be the inhibition of viral binding and entry
into the host cell in an in vitro study. [i2]

Brown seaweed side effects
Different people may experience different side effects and benefits of a product. You are encouraged to report adverse
side effects to FDA, its website is, or report the adverse side effects to the manufacturer, you should be
able to find the contact information on the label. There is not enough information available to know if brown algae are
safe to take for medical conditions, and there is no official report on its side effects. Probably, intake of a small amount
of brown seaweed does not have serious side effects. However, it may contain heavy metals.


Reference: [1] Anti-obesity compound found in brown seaweed 232nd American Chemical Society National Meeting in
San Francisco  Reuters Mon Sep 11, 2006. Anti-obesity compound found in brown seaweed BBC, Sep 11, 2006. [3]
Maeda H, et al, Fucoxanthin from edible seaweed, Undaria pinnatifida, shows antiobesity effect through UCP1
expression in white adipose tissues. Biochem Biophys Res Commun. 2005 Jul 1;332(2):392-7. [4] Murata M, et al,
Dietary fish oil and Undaria pinnatifida (wakame) synergistically decrease rat serum and liver triacylglycerol. J Nutr.
2002 Apr;132(4):742-7. [T1] Maruyama H, et al, Antitumor activity and immune response of Mekabu fucoidan extracted
from Sporophyll of Undaria pinnatifida. In Vivo. 2003 May-Jun;17(3):245-9.  [A1] Suetsuna K, et al, Identification of an
antihypertensive peptide from peptic digest of wakame (Undaria pinnatifida). J Nutr Biochem. 2000 Sep;11(9):450-4.
[A2] Sato M, et al,  Angiotensin I-converting enzyme inhibitory peptides derived from wakame (Undaria pinnatifida) and
their antihypertensive effect in spontaneously hypertensive rats. J Agric Food Chem. 2002 Oct 9;50(21):6245-52. [I1]
Cooper R, GFS, a preparation of Tasmanian Undaria pinnatifida is associated with healing and inhibition of reactivation
of Herpes. BMC Complement Altern Med. 2002 Nov 20;2:11. Epub 2002 Nov 20. [i2] Thompson KD, et al, Antiviral
activity of Undaria pinnatifida against herpes simplex virus. Phytother Res. 2004 Jul;18(7):551-5. [A3] Murata M, et al,
Hepatic fatty acid oxidation enzyme activities are stimulated in rats fed the brown seaweed, Undaria pinnatifida
(wakame). J Nutr. 1999 Jan;129(1):146-51. [A4] Suetsuna K, et al, Antihypertensive effects of Undaria pinnatifida
(wakame) peptide on blood pressure in spontaneously hypertensive rats. J Nutr Biochem. 2004 May;15(5):267-72.
Ikeda K,et al, . Effect of Undaria pinnatifida (Wakame) on the development of cerebrovascular diseases in stroke-prone
spontaneously hypertensive rats. Clin Exp Pharmacol Physiol. 2003 Jan-Feb;30(1-2):44-8. [A6] Ito S, Miyoshi T.
[Determination of Mg and Zn contents of Naruto "wakame" (Undaria pinnatifida)] Nippon Eiseigaku Zasshi. 1990 Aug;45
(3):795-800. [A7] Lordan S et al, The α-amylase and α-glucosidase inhibitory effects of Irish seaweed extracts.
Lordan S, Smyth TJ, Soler-Vila A, Stanton C, Ross RP. Food Chem. 2013 Dec 1;141(3):2170-6 [A8] Yang L et al,
Fucoidan derived from Undaria pinnatifida induces apoptosis in human hepatocellular carcinoma SMMC-7721 cells via
the ROS-mediated mitochondrial pathway. Mar Drugs. 2013 Jun 10;11(6):1961-76 [A9] Ruxton CH, Jenkins G. A novel
topical ingredient derived from seaweed significantly reduces symptoms of acne vulgaris: a general literature review. J
Cosmet Sci. 2013 May-Jun;64(3):219-26.

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In 1960s, wakame, the brown seaweed, became popular in the United States, widely available in Asian-American grocery stores. Wakame fronds
are green and have a subtly sweet flavour and slippery texture. The leaves are be cut into small pieces as they will expand during cooking. Wakame
is distributed either dried or salted, and used in miso soup and other preparations such as tofu salad. Goma wakame, or seaweed salad, is a
popular side dish at American sushi restaurants. Wakame is a rich source of eicosapentaenoic acid, an omega-3 fatty acid, wakame is also a good
source of magnesium and zinc. [A6]

Asian soups and salads, contains a compound called fucoxanthin that promotes weight loss.
Fucoxanthin is found at high concentrations in several
different types of brown seaweed. But it is absent in green and red seaweeds. Brown kelp is a key ingredient of Japanese miso soup. But the
researchers said drinking large quantities of the soup has a little effect on weight loss.  [1,2]