Agar-Agar, Agarose, Agarose Gel, Agaropectin, Agarweed, Algue de Java, Chinese Gelatin, Colle du Japon, Garacilaria confervoides, Gélatine de Chine, Gelidiella acerosa, Gelidium amanasii, Gelidium cartilagineum, Gelidium crinale, Gelidium divaricatum, Gelidium pacificum, Gelidium vagum, Gelosa, Gelosae, Gélose, Japanese Isinglas, Kanten Diet, Kanten Jelly, Kanten Plan, Layor Carang, Mousse de Ceylan, Mousse de Jaffna, Qion Zhi, Seaweed Gelatin, Vegetable Gelatin, Vegetarian Gelatin.
Agar is a plant. People use it to make medicine.
People take agar to lose weight, especially in Japan. In Japan agar is called “kanten,” and it is the main ingredient in “the kanten plan” or “the kanten diet.”
Agar is also used to treat diabetes and constipation.
In dentistry, agar is used to make dental impressions.
In manufacturing processes, agar is used as an ingredient in emulsions, suspensions, gels, and certain suppositories.
How does it work?
Agar contains a gel-like substance that bulks up in the gut. This stimulates the intestines and creates a bowel movement. That’s why agar is commonly used as a laxative.
Agar’s bulking effect also explains its use for weight loss. Agar tends to make people feel full, so they might stop eating earlier than they otherwise would. Some people think this reaction will lead to weight loss. But so far, there is no reliable scientific evidence that supports this weight loss theory.
Possibly Effective for...
- Obesity. Taking a product containing agar gel (Slim Kanten) by mouth daily while following a traditional Japanese diet for 12 weeks appears to reduce body weight and body mass index in obese people with type 2 diabetes and impaired glucose tolerance more effectively than following a traditional Japanese diet alone.
Insufficient Evidence to Rate Effectiveness for...
- Diabetes. Taking a product containing agar gel (Slim Kanten) by mouth daily while following a traditional Japanese diet for 12 weeks does not improve pre-meal blood sugar levels or insulin resistance in obese people with type 2 diabetes and impaired glucose tolerance more effectively than following a traditional Japanese diet alone. However, agar seems to help lower body weight and body mass index in these individuals.
- High levels of a chemical called bilirubin in the blood of newborns (infant jaundice). Most early research suggests that giving agar by mouth for 5 days does not reduce bilirubin levels in infants with newborn jaundice. However, when given by mouth along with light therapy, agar seems to increase the bilirubin-lowering effects of light therapy and reduce the length of time that light therapy is needed.
- Other conditions.
Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).
Agar is POSSIBLY SAFE for most adults when taken by mouth with at least one 8-ounce glass of water. If it is not taken with enough water, agar can swell and block the esophagus or bowel. Immediate medical attention is necessary if chest pain, vomiting, or difficulty swallowing or breathing occurs after taking agar. In some people, agar may also raise cholesterol.
Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking agar if you are pregnant or breast-feeding. Stay on the safe side and avoid use.
Bowel blockage (obstruction): Agar might make bowel obstruction worse, especially if it isn’t taken with enough water or other liquid. Get medical advice before taking agar if you have a bowel obstruction.
Trouble swallowing: Agar might swell up and block the eating tube (esophagus) if it isn’t taken with enough water or other liquid. This can be especially dangerous for someone who has trouble swallowing. Get medical advice before taking agar if you have a swallowing problem.
Colon cancer: There is some concern that eating a certain type of dietary fiber, such agar, might increase the risk of developing colon tumors. Get medical advice before taking agar if you have a history of or are at risk for colon cancer.
Medications taken by mouth (Oral drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.
Agar is a thick gel. Agar might stick to some medications in the stomach and intestines. Taking agar at the same time as medications that you take by mouth might decrease how much medication your body absorbs, and possibly decrease the effectiveness of your medication. To prevent this interaction, take agar at least one hour after medications you take by mouth.
The appropriate dose of agar depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for agar. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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Osada, T., Shibuya, T., Kodani, T., Beppu, K., Sakamoto, N., Nagahara, A., Ohkusa, T., Ogihara, T., and Watanabe, S. Obstructing small bowel bezoars due to an agar diet: diagnosis using double balloon enteroscopy. Intern.Med 2008;47(7):617-620. View abstract.
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American Academy of Pediatrics Subcommittee on Hyperbilirubinemia. Management of hyperbilirubinemia in the newborn infant 35 or more weeks of gestation. Pediatrics 2004;114(1):297-316.