Fucus vesiculosus, a type of seaweed commonly called bladderwrack, has been used traditionally and in alternative medicine to treat a wide variety of health conditions. Research is lacking on its effectiveness, and many side effects are possible when taken as a supplement or consumed in large amounts.
Types
Bladderwrack kelp is available as a supplement in tablets, extract or capsules. It also can be eaten as a vegetable, for instance in salads and soups.
Benefits
The U.S. National Institutes of Health (NIH) indicates the possibility of bladderwrack benefit for anti-bacterial, anti-fungal, anticoagulant and antioxidant properties. It also may lower blood sugar levels and suppress the growth of cancer cells. Clear scientific evidence is lacking, however.
Considerations
Most negative effects from bladderwrack seem to result from the high iodine content or contamination with heavy metal, according to the National Institutes of Health (NIH).
Iodine
Iodine may cause brassy taste sensations, increased salivation and upset stomach. High iodine content also can lead to thyroid disorders. The NIH notes that some bladderwrack users have reported severely worsening acne, a condition connected with dietary iodine.
Additional Effects
Chronic use of bladderwrack has a laxative effect. Abnormal bleeding and reduced blood platelets also have been reported. Reports of kidney and nerve damage appear related to heavy metal contamination, according to the NIH.
Contraindications
People taking anticoagulants, thyroid medications or medications for diabetes may not be able to safely consume bladderwrack kelp. Pregnant women should not take bladderwrack because of high iodine levels and the possibility of heavy metal contamination.
Tags: heavy metal, heavy metal contamination, high iodine, Institutes Health, iodine content, metal contamination