Mannose is a simple sugar contained in certain plants. There are several isomers of mannose, and two general forms, L-mannose and D-mannose. D-mannose appears to be the most biologically active of the two.
D-mannose is used to make glycoproteins
While some have concluded that D-mannose is not utilized in metabolism, research has concluded otherwise. A number of studies (such as Pannerselvam et al. 1997) have concluded that the human liver utilizes mannose to produce glycoproteins. This study, in fact, also showed that fibroblast cells prefer using mannose than glucose for the manufacture of glycoproteins.
Glycoproteins are important sugar-protein complexes that make up the mucus linings of our various tracts (intestinal, urinary, etc.). They are also part of hormones, some enzymes, collagens and certain immune cells.
The mannose not utilized by the cells is purged from the body through the urine. This is where mannose’s acclaimed affects on bladder and kidney infections comes from.
D-mannose inhibits bacteria adhesion
Several studies have shown that taking D-mannose will reduce bacterial infection. In one study, 73 E. coli strains were collected and identified from urinary tract infections of women. D-mannose completely inhibited the ability of 25 of the strains from adhering from vagina cells, and 11 strains were partially (at least 50%) inhibited (Schaeffer et al. 1984).
Another study (Toyota et al. 1989) showed that mannose in the urine prevented many bacteria from attaching to the urinary tract.
The ability of bacteria to adhere to our urinary tracts – and any other lining of our body for that matter – is a big deal. The entire world is covered by bacteria. With every touch and breath, we are in contact with bacteria. The question is whether those bacteria will attach. And if they do attach, will our immune systems be strong enough to take them apart.
Clinical use of D-mannose
The use of D-mannose to counteract urinary infections (bladder and kidney) is not well-known. However, this does not mean that no one is utilizing it. Jonathan Wright, M.D. has been utilizing D-mannose in his Tahoma clinic with success. There have also been anecdotal testimonies that D-mannose has helped sinus infections and prostate infections. These have not been confirmed by research, however.
Sources of D-mannose
Today there are a number of supplement forms of D-mannose available. (Remember that these are not intended to treat or cure any disease. Consult your doctor before using.)
However, we should also know that a varied plant-based whole food diet will typically contain a healthy amount of mannose.
Foods that are high in mannose include cranberries, currants, gooseberries, soybeans, beans, cayenne pepper, eggplant, turnips, tomatoes and green beans. Aloe vera is also a good source of mannose.
Mannose is part of the matrix of sugars that reside in these whole foods. When whole foods are processed with excessive heat and refining techniques, mannose and other nutrients can be lost in the equation.
It is interesting that many mannose foods are also known to be extremely useful for our digestive tract and urinary tract. Mannose is used to make the glycoproteins that line these tracts. And the mannose not utilized is purged through the urinary tract where it inhibits the attachment and growth of bacteria.
A testament of one of the many mechanisms nature uses to support health.
Schaeffer AJ, Chmiel JS, Duncan JL, Falkowski WS. Mannose-sensitive adherence of Escherichia coli to epithelial cells from women with recurrent urinary tract infections. J Urol. 1984 May;131(5):906-10.
Toyota S, Fukushi Y, Katoh S, Orikasa S, Suzuki Y. Anti-bacterial defense mechanism of the urinary bladder. Role of mannose in urine. Nippon Hinyokika Gakkai Zasshi. 1989 Dec;80(12):1816-23.
Panneerselvam K, Etchison JR, Freeze HH. Human fibroblasts prefer mannose over glucose as a source of mannose for N-glycosylation. Evidence for the functional importance of transported mannose. J Biol Chem. 1997 Sep 12;272(37):23123-9.
This information is for research purposes only. Be sure to consult your health professional if you suspect you have any disease, and before making any significant changes to your diet, lifestyle or supplements.