Bladderwrack is a type of brown seaweed. The name comes from the air pockets in its leaves, which look like small bladders. The air pockets help the seaweed float.
Bladderwrack grows in the ocean, near the northern coasts of the United States, on both the Pacific and Atlantic sides. It also grows on the northern coasts of Europe, on the Atlantic and Baltic sides.
Bladderwrack is in the kelp family, and some people may refer to it by that name. But kelp is a generic name for many different types of brown seaweed. The term does not refer specifically to bladderwrack.
The main stem of bladderwrack — the thallus — is used for medicinal supplements to treat several different conditions. However, more study is needed to clearly determine its effectiveness.
May Relieve Constipation or Diarrhea
Bladderwrack contains alginic acid, a kind of dietary fiber. Fiber helps with constipation, but it can also relieve diarrhea and keep your bowel movements more regular in general. However, more research is needed to prove the effectiveness of bladderwrack at treating these conditions.
May Help With Gastroesophageal Reflux Disease (GERD)
GERD is chronic acid reflux. It irritates the lining of the esophagus and causes heartburn at least a few times per week. Some people manage it with lifestyle changes, but others take medications or supplements.
One over-the-counter medication, Gaviscon, uses alginic acid — found in bladderwrack — in combination with magnesium carbonate to treat heartburn and GERD. However, researchers need to perform more studies to see if bladderwrack would be an effective treatment for GERD on its own.
May Relieve Other Stomach Problems
Bladderwrack may relieve stomach problems because it creates a barrier between your sensitive stomach lining and irritants, like stomach acid. It also lowers inflammation, which may relieve some digestive issues.
The other stomach problems bladderwrack may help include:
- Gastritis (swelling and irritation of the stomach lining)
- Occasional heartburn
- Low stomach acid levels
May Speed Wound Healing
Early studies show that calcium alginate, a substance found in bladderwrack, may heal wounds faster than other methods. One preliminary study showed that, when aided by a certain form of alginate, serious wounds healed in as few as 10 days. However, more research is needed to determine the most effective dosage and application style of bladderwrack for wound care.
May Prevent Hypothyroidism
Traditionally, people living near the ocean in areas where bladderwrack grows have lower rates of hypothyroidism. Some speculate this is because their diets contain higher levels of iodine from fish, shellfish, and seaweeds like bladderwrack.
Symptoms of hypothyroidism include:
- Weight gain and slower metabolism
- Intolerance of colder temperatures
- Dry and coarse hair
- Heavy menstruation
- Hoarse or weak voice
Iodine, found in sea salt and many foods that come from the ocean, is an important nutrient for thyroid health. Your thyroid needs iodine to produce regulating hormones that keep your body functioning normally. However, your body does not produce iodine on its own. So you need to eat it in a food or supplement, like bladderwrack.
Today, most people eat salt that has iodine added to it at least some of the time. Before this was a common practice, many people who did not live near the ocean — and did not get enough iodine in their diet — had a higher incidence of thyroid disease.
While more research is needed to test bladderwrack's efficiency against thyroid disease, seaweed in general has the most iodine content out of any food.
While bladderwrack may help certain thyroid issues, it may exacerbate others. Talk to your doctor about using bladderwrack for your thyroid condition before you start.
Some people have an allergy to iodine. Due to the high iodine content of bladderwrack, you should avoid taking it in any form if you’re allergic.
Bladderwrack can increase your risk of excessive bleeding if you’re on a medication that stops blood from clotting. If you’re on one of these medications, talk to a doctor before taking this supplement.
Amounts and Dosage
There is no officially recommended dose for bladderwrack. More research is needed to determine which forms and dosages are most effective for different health concerns. When taking a bladderwrack supplement, follow the guidance on the packaging.