Brown Seaweed (wakame)
Health Benefits and Side Effects    Zhion 2008
We all probably know that brown seaweed (wakame) is good source of
magnesium and zinc. [A6]

A recent news report that brown seaweed, also known as wakame, Brown kelp, Undaria
pinnatifida -- commonly used to flavor 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]

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 or
Undaria pinnatifida). [3]

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]

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.
Prior studies demonstrated its potential health benefits on cancer. Flucoxanthin helps
promote the death of human prostate cancer cells in culture.

What are other potential health benefits of brown kelp?
Brown seaweed (brown kelp) benefits hyperlipidemia in animal studies.
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]

Brown seaweed (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 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 (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 extracts showed benefits in cancer in a study of mice.
Japanese researchers showed that fucoidan, extracted from dietary seaweed, could inhibit
tumor growth in a mice study. They found that 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]

THIS ARTICLE IS FOR YOUR INFORMATION ONLY. IF YOU HAVE ANY QUESTION, YOU SHOULD
CONSULT WITH YOUR DOCTOR. ANY SEA PRODUCT MAY BE CONTAMINATED WITH HEAVY METALS.  
MOST RESEARCH STUDIES WERE DONE IN ANIMALS. SIDE EFFECTS AND EFFICACIES OF BROWN
SEAWEEDS IN HUMAN ARE UNKNOWN. ALL RIGHTS RESERVED 2006 ZHION.

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.