Arctostaphylos: Uva ursi and alkaline urine

Is an alkaline urine necessary for uva ursi and other UTI herbs to be effective?

Although the scientific literature is almost unanimous on this point (Frohne; Lawrence; Madaus; Wichtl), it is not necessarily so. Common scientific wisdom states that the antibacterial activity of uva ursi is due to hydroquinone which is produced by breaking down the constituent arbutin (6-10% of iva ursi by weight) in an environment of alkaline urine. However, uva ursi was used successfully to treat UTI many centuries before urbutin or hydroquinone were ever heard of, and no special precautions were taken before this latest theory of the active ingredient emerged. The urine is normally slightly acid [pH 6; range 4.5-8.2 (neutral=7.0, lower numbers are more acid)], and may swing from acid to base and back during the course of a day. Infection by E. coli, the most common infectious agent in UTI, makes the urine even more acidic (Graff), so it seems likely that uva ursi can be of benefit even with an acid urine. Note: infection by urea-splitting bacteria such as proteus and psudomonas cause an alkaline urine. It is entirely possible that other constituents in uva ursi are active, and that some activity of arbutin may contribute to the overall effect of the plant even in acid urine.

Can urine be alkalinized by taking baking soda?

According to the German reference Teedrogen (Wichtl), sodium bicarbonate will cause an alkaline state in the urine, but only for short periods of time. The acid-base system of body is kept in balance via three major biochemical buffering systems, involving both the urinary and the respiratory systems, and small amounts of base added to the system are quickly compensated for by these systems. Abuse of sodium bicarbonate, on the other hand can be a problem. The elderly sometimes use it as an inexpensive home treatment for indigestion, and have been known to experience overexcitability of the nervous system, and even convulsions, side effects of severe systemic alkalosis.

How can the urine be reliably alkalinized?

Conventional texts in both the U.S. and Europe recommend a low-protein, high fruit and vegetable diet to alkalinize the urine (Graff; Wichtl), especially vegetables and citrus. Potassium deficiency may also cause acid urine, so adequate potassium should be maintained in the diet. This is normally not a problem with a vegetarian diet. Several pathological conditions may also cause alkaline urine, including the chronic use of diuretics, excess aldosterone, and excessive vomiting of gastric contents without lower gastrointestinal contents.

Is the urine more alkaline at times of the day?

The rush of acid into the stomach after a meal creates a relative alkalinization of the rest of the system, resulting in what is called an “alkaline tide” in the urine following meals. This suggests that uva ursi might best be taken several hours before a meal. According to the official German monograph, the maximum antibacterial effects of uva ursi in the urine come three to four hours after administration.


Frohne D. “Untersuchungen zur frage der harndes ifizierenden wirkungen von barentraubenblatt extrakten.” Planta Medica 18(1): 1970

Graff, L. Handbook of routine urinalysis. Lippencott. 1983

Lawrence Review of Natural Products. Uva ursi. September 1987.

Madaus G. Lehrbuch der biologischen heilmittel. Georg Olms Verlag. Hildesheim; New York. 1938

Wichtl, M. Teedrogen. Wissenschaftliche Verlag Gesellschaft. Stuttgart.
  Copyright 2001 Paul Bergner

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