Agar
OTHER NAME(S): Agar-Agar, Agarose, Agarose Gel, Agaropectin, Agarweed, Algue de Java, Chinese Gelatin, Colle du Japon, Gelosa, 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, Gelosae, Seaweed Gelatin, Kanten, Kanten jellies, Agar-agar
Overview
Agar is a plant. People use it to make medicine. In Japan agar is called "kanten," and it is the main ingredient in "the kanten plan" or "the kanten diet."
People use agar for obesity, diabetes, constipation, yellowing of the skin in infants (neonatal jaundice), and other conditions, but there is no good scientific evidence to support these uses.
Agar contains a gel-like substance that bulks up in the gut. This stimulates the intestines and creates a bowel movement. This bulking effect is thought to make it useful as a laxative and 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 not enough reliable scientific evidence that supports this weight loss theory.
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.
Agar contains a gel-like substance that bulks up in the gut. This stimulates the intestines and creates a bowel movement. This bulking effect is thought to make it useful as a laxative and 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 not enough reliable scientific evidence that supports this weight loss theory.
Uses
Insufficient Evidence for
- Diabetes. Early research shows that taking agar gel by mouth daily while following a traditional Japanese diet for 12 weeks doesn't improve pre-meal blood sugar levels or insulin resistance in obese people with type 2 diabetes and impaired glucose tolerance.
- Yellowing of the skin in infants (neonatal jaundice). While research is mixed, most early research shows that giving agar by mouth for 5 days doesn't reduce bilirubin levels in infants with newborn jaundice. But when given by mouth along with light therapy, agar might increase the bilirubin-lowering effects of light therapy. It might also reduce the length of time that light therapy is needed.
- Obesity. Early research shows that taking agar gel by mouth daily while following a traditional Japanese diet for 12 weeks reduces body weight by a small amount in obese people with type 2 diabetes and impaired glucose tolerance.
- Constipation.
- Other conditions.
More evidence is needed to rate the effectiveness of agar for these uses.
Side Effects
When taken by mouth: Agar is POSSIBLY SAFE for most adults when taken 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.
Precautions
When taken by mouth: Agar is POSSIBLY SAFE for most adults when taken 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.
Children: Agar is POSSIBLY SAFE when given by mouth to infants with neonatal jaundice for up to 7 days.
Pregnancy and breast-feeding: There isn't enough reliable information to know if agar is safe to use when 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.
Interactions
Minor Interaction
Be watchful with this combination
- Medications taken by mouth (Oral drugs) interacts with AgarAgar is a thick gel. Taking agar by mouth at the same time as medications might decrease how much medication your body absorbs. This could decrease the effectiveness of your medication. To prevent this possible interaction, take agar at least one hour after taking medications by mouth.
Dosing
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.
References
- Monographs on the medicinal uses of plant drugs. Exeter, UK: European Scientific Co-op Phytother, 1997.
- Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
- Tyler VE. Herbs of Choice. Binghamton, NY: Pharmaceutical Products Press, 1994.
- Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
- Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
- McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
- Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
- Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
- Kondo H, Osada A. Influence of dietary fiber on the bioavailability of zinc in rats. Biomed Environ Sci. 1996 Sept;9(2-3):204-8.
- Schneeman, B. O. Fiber, inulin and oligofructose: similarities and differences. J Nutr 1999;129(7 Suppl):1424S-1427S.
- Romagnoli, C., Polidori, G., Foschini, M., Cataldi, L., De, Turris P., Tortorolo, G., and Mastrangelo, R. Agar in the management of hyperbilirubinaemia in the premature baby. Arch.Dis.Child 1975;50(3):202-204.
- Colomer, J., Moya, M., Marco, V., De, Paredes C., Escriva, F., and Vila, R. [Variations in hyperbilirrubinemia in low birth weight newborns under phototherapy and continous or discontinous agar oral administration (author's transl)]. An.Esp.Pediatr. 1975;8 Suppl 1:27-32.
- Windorfer, A., Jr., Kunzer, W., Bolze, H., Ascher, K., Wilcken, F., and Hoehne, K. Studies on the effect of orally administered agar on the serum bilirubin level of premature infants and mature newborns. Acta Paediatr.Scand. 1975;64(5):699-702.
- Dennery, P. A. Pharmacological interventions for the treatment of neonatal jaundice. Semin.Neonatol. 2002;7(2):111-119.
- Hoie, L. H., Morgenstern, E. C., Gruenwald, J., Graubaum, H. J., Busch, R., Luder, W., and Zunft, H. J. A double-blind placebo-controlled clinical trial compares the cholesterol-lowering effects of two different soy protein preparations in hypercholesterolemic subjects. Eur.J.Nutr. 2005;44(2):65-71.
- Maeda, H., Yamamoto, R., Hirao, K., and Tochikubo, O. Effects of agar (kanten) diet on obese patients with impaired glucose tolerance and type 2 diabetes. Diabetes Obes.Metab 2005;7(1):40-46.
- Minekus, M., Jelier, M., Xiao, J. Z., Kondo, S., Iwatsuki, K., Kokubo, S., Bos, M., Dunnewind, B., and Havenaar, R. Effect of partially hydrolyzed guar gum (PHGG) on the bioaccessibility of fat and cholesterol. Biosci.Biotechnol.Biochem. 2005;69(5):932-938.
- Chen, H., Yan, X., Zhu, P., and Lin, J. Antioxidant activity and hepatoprotective potential of agaro-oligosaccharides in vitro and in vivo. Nutr J 2006;5:31.
- Sanaka, M., Yamamoto, T., Anjiki, H., Nagasawa, K., and Kuyama, Y. Effects of agar and pectin on gastric emptying and post-prandial glycaemic profiles in healthy human volunteers. Clin Exp.Pharmacol.Physiol 2007;34(11):1151-1155.
- 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.
- Calvert, R., Schneeman, B. O., Satchithanandam, S., Cassidy, M. M., and Vahouny, G. V. Dietary fiber and intestinal adaptation: effects on intestinal and pancreatic digestive enzyme activities. Am J Clin Nutr 1985;41(6):1249-1256.
- Calle-Pascual, A. L., Marenco, G., Asis, M. J., Bordiu, E., Romeo, S., Romero, C., Martin, P. J., Maranes, J. P., and Charro, A. L. Effects of different proportions of carbohydrates, polysaccharides/monosaccharides, and different fibers on the metabolic control in diabetic rats. Metabolism 1986;35(10):919-923.
- Kemper, K., Horwitz, R. I., and McCarthy, P. Decreased neonatal serum bilirubin with plain agar: a meta-analysis. Pediatrics 1988;82(4):631-638.
- Meloni, T., Costa, S., Corti, R., and Cutillo, S. Agar in control of hyperbilirubinemia of full-term newborn infants with erythrocyte G-6-PD deficiency. Biol.Neonate 1978;34(5-6):295-298.
- Moller, J. Agar ingestion and serum bilirubin values in newborn infants. Acta Obstet.Gynecol.Scand.Suppl 1974;29:61-63.
- Maurer, H. M., Shumway, C. N., Draper, D. A., and Hossaini, A. A. Controlled trial comparing agar, intermittent phototherapy, and continuous phototherapy for reducing neonatal hyperbilirubinemia. J Pediatr. 1973;82(1):73-76.
- Blum, D. and Etienne, J. Agar in control of hyperbilirubinemia. J Pediatr 1973;83(2):345.
- Schellong, G., Quakernack, K., and Fuhrmans, B. [The influence of agar feeding on serum bilirubin in the physiologic jaundice of the newbron infant (author's transl)]. Z.Geburtshilfe Perinatol. 1974;178(1):34-39.
- Bueno, A., Perez-Gonzalez, J., and Bueno, M. [Effect on agar on neonatal bilirubin seric levels (author's transl)]. An.Esp.Pediatr 1977;10(10):721-730.
- Gardner, D. F., Schwartz, L., Krista, M., and Merimee, T. J. Dietary pectin and glycemic control in diabetes. Diabetes Care 1984;7(2):143-146.
- Odell, G. B., Gutcher, G. R., Whitington, P. F., and Yang, G. Enteral administration of agar as an effective adjunct to phototherapy of neonatal hyperbilirubinemia. Pediatr Res 1983;17(10):810-814.
- Wilmshurst, P. and Crawley, J. C. The measurement of gastric transit time in obese subjects using 24Na and the effects of energy content and guar gum on gastric emptying and satiety. Br.J Nutr 1980;44(1):1-6.
- Lavin, J. H. and Read, N. W. The effect on hunger and satiety of slowing the absorption of glucose: relationship with gastric emptying and postprandial blood glucose and insulin responses. Appetite 1995;25(1):89-96.
- French, S. J. and Read, N. W. Effect of guar gum on hunger and satiety after meals of differing fat content: relationship with gastric emptying. Am J Clin Nutr 1994;59(1):87-91.
- Ebbesen, F. and Moller, J. Agar ingestion combined with phototherapy in jaundiced newborn infants. Biol.Neonate 1977;31(1-2):7-9.
- Caglayan, S., Candemir, H., Aksit, S., Kansoy, S., Asik, S., and Yaprak, I. Superiority of oral agar and phototherapy combination in the treatment of neonatal hyperbilirubinemia. Pediatrics 1993;92(1):86-89.
- Holt, S., Heading, R. C., Carter, D. C., Prescott, L. F., and Tothill, P. Effect of gel fibre on gastric emptying and absorption of glucose and paracetamol. Lancet 3-24-1979;1(8117):636-639.
- Kim, S. W., Doh, J. H., and Choe, J. W. Oral Agar and Conventional Phototherapy Combination in the Treament of Neonatal Hyperbilirubinemia. J Korean Pediatr Soc 1997;40(7):931-938.
- Ross, K. A., Pyrak-Nolte, L. J., and Campanella, O. H. The effect of mixing conditions on the material properties of an agar gel-microstructural and macrostructural considerations. Food Hydrocolloids 2006;20(1):79-87.
- 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.
- Harmuth-Hoene, A. E. and Schelenz, R. Effect of dietary fiber on mineral absorption in growing rats. J Nutr 1980;110(9):1774-1784.
- Abdel-Aziz Ali SMA, Mansour Galal S, Sror SM, Hussein O, Abd-El-Haseeb Ahmed AO, Hamed EA. Efficacy of oral agar in management of indirect hyperbilirubinemia in full-term neonates. J Matern Fetal Neonatal Med. 2020:1-6.
- Reshma BS, Aavula T, Narasimman V, Ramachandran S, Essa MM, Qoronfleh MW. Antioxidant and Antiaging Properties of Agar Obtained from Brown Seaweed Laminaria digitata (Hudson) in D-Galactose-Induced Swiss Albino Mice. Evid Based Complement Alternat Med 2022;2022:7736378.
- Shirai I, Karasawa K, Kodaira Y, et al. Intestinal permeability of agaro-oligosaccharides: Transport across Caco-2 cell monolayers and pharmacokinetics in rats. Front Nutr 2022;9:996607.