Urine and pH
Urine is the product of renal excretion, through which the metabolic or catabolic products dissolved in the blood stream are expelled from the body (harmful waste products, especially urea , ketone bodies , creatinine, etc.).
Controlling urinary pH means evaluating and measuring the ability of the kidney to acidify the urine; the latter, together with the exhaled breath ( pulmonary ventilation ), are responsible for the acid-base balance of the blood through the expulsion of NOT volatile acids (hydrogen ions) produced normally and daily by the metabolism(about 60mEq). The hydrogen ions, if not expelled, cause the lowering of the blood pH and the metabolic acidosis ; any difficulty in producing and eliminating acidic urine in conditions of metabolic acidosis almost always suggests renal insufficiency.
As can be easily guessed from what has been described above, the pH of urine can fluctuate significantly and represents an indispensable condition for maintaining blood homeostasis (prevention of systemic acidification or alkalosis); normally, urine pH is between 4.4 and 8, with normality at 6/7.
Acidify Urine
Urine acidification is useful in the prevention and treatment of cystitis (infection of the bladder ), urethritis ( infection of the urethra ), and urethrocystitis (bladder + urethra). It is also used in pharmacology to modulate the effect of some drugs, favoring the elimination of weak bases (useful practice for example in case of amphetamine overdose ) and hindering the excretion of weak acids (in this case urinary acidification reduces drug elimination by prolonging its half-life).
The bacteria that infect the, a microbial strain particularly sensitive to the surrounding pH. In acidic conditions, Escherichia coli is NOT able to reproduce effectively, therefore, in case of urinary tract infections it is still useful to try to acidify the urine.
The most used food (and the only one subjected to clinical trials) in the treatment of urinary infections (by virtue of its power to acidify the urine and above all to prevent bacterial adhesion to the urinary mucosa) is cranberry juice . The latter is a drink obtained from the fruits of the American cranberryand it seems that if consumed in portions of 500-750 ml/day it can favor the prevention and remission of the aforementioned pathologies; however, as often happens, the experimental results are still controversial but it is still necessary to specify that it is a food and not a drug; therefore, being characterized by the TOTAL absence of contraindications, it is always advisable to use it.
Other foods useful for acidifying the urine are all those containing an abundant acid residue deriving from chlorine (Cl), phosphorus (P) and sulfur (S). In particular, the foods useful for acidifying the urine are: cheeses , egg yolks , white and red meats ,fish ; followed by dried fruit , legumes and cereals .
Other methods: Contraindications
Urine acidification can occur as a result of inappropriate dietary behaviors such as ketogenic (or generally hyperproteic ) diets , but also in PROTRACT post -exercise . In both cases, also due to dehydration , the pH of the urine undergoes acidification due to:
- Chetonic bodies
- nitrogenous residues
Although they also contribute to urine acidification, from my point of view it is absolutely inadvisable to exploit these obsolete and generally unwanted conditions; the negative aspect that precludes their use in therapy against urinary tract infections is the potentially tiring effect they exert on the renal filtration system (see ketogenic diet )… without considering that both ketone bodies and nitrogenous residues , in addition to acidifying the urine, cause systemic impairment which, in some cases (such as in renal insufficiency ) can lead to severe metabolic acidosis.
PLEASE NOTE: regardless of the method chosen, in people with hyperuricosuria (high levels of uric acid in the blood) or hypercystinuria (high urinary levels of cystine), acidifying the urine means promoting the formation of stones in the urinary tract; for these categories of patients, urinary alkalization is therefore recommended and urine acidification is strongly discouraged. The same goes for the prevention of osteoporosis , given that a diet CHRONICALLY rich in acid residues favors bone mineral loss.
