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Beta-1 3 Glucan
 

Beta Glucan Introduction

Betas 1,3-glucans are also called beta glucans. These polysaccharides can be found in cereals and grains, such as oats and barley, as well as in yeast, algae, bacteria, and mushrooms. Beta glucans are a water-soluble fiber that consists of chains of glucose molecules.

Being fibrous in nature, Beta glucans are not absorbed in the small intestine like most nutrients. They are partially digested in the large intestine and are broken down into oligosaccharides (long sugar and starch molecules), which can then be absorbed.

Beta glucans are considered to be immune system primers. They bind to specific receptors on macrophages, a special white blood cell that initiates the immune reaction towards bacteria and viruses. By binding to the macrophage, certain immune signaling molecules known as IL-1 and TNF are produced. These signaling molecules increase the production of specialized T cells and NK cells.

Beta glucans are also effective at reducing cholesterol. Although the exact mechanism is not known fully understood, it is most likely due to an increase in bile excretion. Because beta glucans are a soluble fiber, they can also increase the excretion of bile salts in the feces. Bile salts help to bind cholesterol and therefore by increasing their excretion, the absorption of cholesterol in decreased.

Beta glucans have been used for cholesterol lowering effects, enhancing immune system, improving wound healing, anti-cancer activity, and mild blood sugar control.

Beta Glucan Food Sources

Beta glucans are found in several different sources. They are found in the whole grains of oat and barley. They are also found in several mushroom sources such as Shiitake, Maitake, and Reishi. Other sources include yeast cell walls, seaweeds, and certain bacteria.

Oat beta glucans are the only source approved by the FDA to lower cholesterol. The following table lists different sources of oat beta glucans with relative concentration.

Oat Source Relative Amount of beta glucans
Cheerios, 1 cup 3,000 mg
Dried whole oatmeal, 3 Tablespoons 3,000 mg
Oat Bran, 2 Tablespoons 6,000 mg

Table 1: Sources of Oat Beta Glucans

Beta Glucan Uses

Beta glucans are an effective treatment for high cholesterol and may protect against the development of cardiovascular disease. Beta glucans derived from oats, barley, and yeast have all been shown in studies to reduce total cholesterol by decreasing LDL, or bad cholesterol, and in some studies increasing HDL, or good cholesterol levels. [1, 2, 3]

Oat beta glucans have also been shown to improve lipids in those with Type II diabetes mellitus as well as improving blood sugar and Hemoglobin A1C, a marker for diabetes progression. [4]

  • Beta glucans are also helpful for glycemic control and can be helpful at regulating glucose response to a carbohydrate meal that can increase insulin sensitivity. In study, the consumption of beta glucans improved glucose tolerance in Type II diabetics. [5]
  • Beta glucans are immunomodulating and can be effective against various types of cancer. Beta glucans from the seaweed Laminaria digitata have shown anti-tumor cell activity in vitro and vivo. [6]
  • Beta glucans are an effective adjunctive treatment for prostate cancer. They have been shown to improve the effects of chemotoxic medications in certain types of prostate cancer. [7]
  • Lentinan, a beta glucan from the Shiitake mushroom, may slow the progression and restrict the growth of colon cancer cells. [8]
  • The addition of beta glucan to the treatment protocol of individuals with gastric cancer prolonged the survival time when the cancer was non-resectable. [9]
  • Beta glucans also have been shown to improve symptoms of post radiation in patients with cervical cancer. It also prolonged survival time and time to recurrence. [10]
  • Beta glucans have been shown to improve wound healing. In children with partial thickness burns, healing time was increased while reducing fluid loss. Cosmetic outcome was also improved. [11] Beta glucans also improved collagen synthesis and increased the tensile strength of skin during wound healing. [12]
  • Beta glucan can prevent infection via immune system stimulation. In study, beta glucans prevented infection in patients at increased risks by approximately 75% compared to placebo.[ 13]

Beta Glucan Dosages

The usual dosage that has been effective for lowering cholesterol is 3,000 - 15,000 milligrams (mg) per day. Other sources recommend a dosage from 50 mg to 1,000 mg once or twice a day to have an effect on the immune system.

Beta Glucan Toxicities and Deficiencies

Because they are not highly absorbed, there are no known side effects or toxicities associated with beta glucans.

Women who are pregnant or nursing should not take beta glucans because there is little or no information about its effects on growing infants.

Beta glucans does have the potential to lower the blood pressure, however, caution is advised because beta glucans can be synergistic with certain hypoglycemic medications.

Caution is also warranted in individuals with autoimmune disease. Because beta glucans can enhance immune function and stimulate cells in the immune system, auto immune diseases could potentially be aggravated by this polysaccharide.

References

[1] Reyna NY et al. Sweeteners and beta glucans improve metabolic and anthropometrics variables in well controlled type II diabetes mellitus. Am J Ther. 2003 Nov-Dec; 10(6): 438-443.

[2] Behall, KM, Scholfield DJ, Hallfrisch J. Diets containing barley significantly reduce lipids in mildly hypercholesterolemic men and women. Am J Clin Nutr. 2004 Nov; 80(5): 1185-1193.

[3] Bell S, Goldman VM, Bistrian BR, Arnold AH, Ostroff G, Forse RA. Effect of beta glucan from oats and yeast on serum lipids. Crit Rev Food Sci Nutr. 1999 Nov; 39(2): 189-202.

[4] Reyna NY et al. Sweeteners and beta glucans improve metabolic and anthropometrics variables in well controlled type II diabetes mellitus. Am J Ther. 2003 Nov-Dec; 10(6): 438-443.

[5] Hallfrisch J, Sholfield DJ, Behall KM. Diets containing soluble oat extracts improve glucose and insulin response in moderately hypercholesterolemic men and women. Am J Clin Nutr. 1995 Feb; 61(2): 379-384.

[6] Vetvicka V, Yvin JC. Effects of marine beta 1,3 glucan on immune reaction. Int Immunopharmacol. 2004 Jun; 4(6): 721-730.

[7] Finkelstein MP et al. Chemosensitization of carmustine with maitake beta glucan on androgen dependent prostatic cancer cells: involvement of glyoxalose I. J Altern Complement Med. 2002 Oct; 8(5): 573-580/

[8] Ng ML, Yap AT. Inhibition of human colon carcinoma development by Lentinan from Shiitake mushrooms (Lentinus edodes). J Altern Complement Med. 2002 Oct; 8(5): 581-589.

[9] Nakano H et al. A Multi-institutional prospective study of lentinan in advanced gastric cancer patients with unresectable and recurrent disease. Hepatogastroenterolgy. 1999 Jul-Aug; 46(25): 2662-2668.

[10] Okamura K et al. Clinical evaluation of sizofiram combined with irradiation in patients with cervical cancer. A randomized controlled trial, a five-year survival rate. Biotherapy. 1989; 1(2): 103-107.

[11] Delatte SE, Evans J, Hebra A, Adamson W, Othersen HB, Tagge EP. Effectiveness of beta glucan collagen for the treatment of partial thickness burns in children. J Pediatr Surg. 2001 Jan; 36(1): 113-118.

[12] Wei D, Zhang L, Williams DL, Browder IW. Glucan stimulates human dermal fibroblast collagen biosynthesis through nuclear factor –1 dependant mechanism. Wound Repair Regen. 2002 May-Jun; 10(3): 161-168.

[13] De Filippe Junior J et al. Infection prevention in patients with severe multiple trauma with the immunomodulatory beta 1,3 polyglucose (glucan). Surg Gynecol Obstet. 1993 Oct; 177(4): 383-388.