New research shows that although bottled alkaline water has a higher pH than regular water, it is not effective in preventing urinary tract stones because of its negligible alkaline content. Alternative treatments with a higher alkaline content, such as orange juice or baking soda, may be more effective and less expensive.
A recent study published in the Journal of Urology suggests that bottled water labeled as "alkaline water" may not be a viable option for preventing recurrence of urinary tract stones.
"Although alkaline water products have a higher pH than regular water, their alkaline content is negligible—suggesting that they are unable to raise urine pH, which would affect the formation of kidney stones and other urinary tract stones," commented senior author Roshan M. Patel, MD, University of California, Irvine.
碱性水，有时也称为高pH值水，是一种越来越受欢迎的瓶装水。 The pH of tap water is generally around 7.5, in comparison, alkaline water has a higher (more alkaline) pH of between 8 and 10.
In recent years, the consumption and sales of alkaline water have increased dramatically. Proponents claim that alkaline water has various health benefits, including improving hydration and raising urinary tract pH.提高pH值是防止曾患结石的患者形成某些类型尿路结石（尿酸或胱氨酸）的关键策略。
Potassium citrate tablets are commonly prescribed to prevent recurrence of stones. However, many patients do not follow the recommended treatment, which is often related to the need to take a large number of pills multiple times a day. If alkaline water regulates the pH of the urinary system, it may become an attractive alternative for stone prevention.
To assess the potential of high-pH water to prevent urinary tract stones, Dr. Patel's team measured the pH of five commercially available alkaline water products. They also reviewed published data on other types of beverages and over-the-counter products that may raise urine pH.
The five brands tested in the study had similar pH levels, falling within a narrow range of around 10. One of the products contains a small amount of citrate, but it is not listed on the product label. In addition, the alkaline water tested did not have organic anions that can be metabolized by the body into a base, as is provided by potassium citrate tablets.
At a pH of 10, the test product had an alkali content of only 0.1 milliequivalents per liter (mEq/L). The authors say this is an "insignificant" concentration compared to the 40 to 100 mEq/L of metabolic acid the body typically produces each day.
In contrast, some other commercially available products do have the potential to raise pH, notably orange juice, which has an alkali content of up to 15 mEq/L, and is also the product with the lowest estimated cost to achieve a target alkali concentration of 30 mEq per day.
Baking soda is one of the most effective and cost-effective alternatives, but it also has potential issues related to its sodium content. New products that are water-soluble also appear to offer useful and affordable options.
Dr. Patel added: "Our findings may help guide alternative treatment options, including beverages and over-the-counter products, to prevent recurrence of urinary tract stones. The researchers note the limitations of laboratory studies and highlight the need for clinical trials of regimens that increase urine pH."
Compiled source: ScitechDaily