Alkalizing the Urine for Better Health

Acidic urine may be a sign of acid-base imbalance and metabolic acidosis. The kidneys play a crucial role in maintaining acid-base balance and are responsible for excreting excess acid. The metabolic acid load can build up with an unsupplemented high-protein, low-carbohydrate diet. This pattern decreases urinary magnesium, citrate, and pH and increases urinary calcium, phosphate, and uric acid excretion (Schwalfenberg 2012).

Acidosis may not only contribute to kidney stones but can adversely affect detoxification due to a number of factors (Minich 2007):

• Alkalizing the urine and the alkalinity of the renal proximal tubules supports the excretion of toxins.
• Alkalizing foods can positively affect urinary pH within just a few hours.
• Phytonutrients support detoxification and are found in alkalizing foods, including the cruciferous family of vegetables which contain potassium, sulforaphane, and indole-3-carbinol.
• The transporters that move toxins out of the cell are sensitive to pH.
• The alkalizing compound citrate is converted to bicarbonate in the body and supports alkalization as well as energy generation as a Krebs cycle intermediate.

Urine pH can significantly affect the formation of kidney stones. Acidic urine can contribute to the formation of calcium oxalate, cystine, and uric acid kidney stones. In contrast, alkaline urine may contribute to calcium phosphate and struvite (magnesium ammonium phosphate) kidney stones. Urine pH can be increased to 6.5-7 by increasing dietary or supplemental alkalizing factors. If urine pH is too alkaline, it can be lowered to 7 with diet and supplement changes as well (Frassetto 2011).

Increasing dietary or supplemental citrate is one of the easiest ways to alkalize urine, as citrate can be converted directly to bicarbonate. Dietary citrate sources include lemon and lime juice, as well as supplemental potassium citrate (Rahman 2017)

Conditions associated with acidosis and acidic urine:

• Bone loss (Buehlmeier 2012, 2016)
• Diabetes, type 2 (Maalouf 2010)
• Gout (Xue 2021)
• Insulin resistance and metabolic syndrome (Ferraro 2020)
• Obesity (Frassetto 2011)
• Uric acid crystallization at a urine pH of 5.5. or below (Kamphuis 2019)

Compounds associated with acidic urine:

• Betaine (Frassetto 2011)
• Cranberry juice (Frassetto 2011)
• Free fructose in excess or from sucrose (Taylor 2008)
• High-protein, low-carbohydrate diet (Schwalfenberg 2012)
• Meat and non-dairy animal products (Ferraro 2020)
• Sodium chloride in excess (Buehlmeier 2012, 2016)

Compounds that help alkalize urine include:

• Alkaline diet (Pizzorno 2010)
• Alkaline mineral water rich in bicarbonate (Wynn 2009)
• Citrate supplementation, lemon or lime juice (Frassetto 2011)
• Fruits and vegetables (Ferraro 2020, Frassetto 2011)
• Potassium bicarbonate (Barbera 2016, Cicerello 2010, Buehlmeier 2012, 2016)
• Potassium citrate (Minich 2007, He 2010 Cicerello 2010)
• Sodium bicarbonate (Xue 2021) (sodium as tolerated)

Optimal Takeaways for Alkalizing Urine

• Increase intake of vegetables, lemon juice, or lime juice, and alkaline water
• Decrease intake of meat and non-dairy animal protein, excess sodium, excess sugar, and excess free fructose, especially from high-fructose corn syrup
• Consider supplementing with potassium citrate and potassium bicarbonate for low-sodium choices
• Strive for a urine pH of 6.5-7

References

Barbera, Michele et al. “The importance of potassium citrate and potassium bicarbonate in the treatment of uric acid renal stones.” Archivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica vol. 88,4 341-342. 30 Dec. 2016, doi:10.4081/aiua.2016.4.341

Buehlmeier, Judith et al. “Alkaline salts to counteract bone resorption and protein wasting induced by high salt intake: results of a randomized controlled trial.” The Journal of clinical endocrinology and metabolism vol. 97,12 (2012): 4789-97. doi:10.1210/jc.2012-2857

Buehlmeier, Judith et al. “Glucocorticoid activity and metabolism with NaCl-induced low-grade metabolic acidosis and oral alkalization: results of two randomized controlled trials.” Endocrine vol. 52,1 (2016): 139-47. doi:10.1007/s12020-015-0730-7

Cicerello, Elisa et al. “Urinary alkalization for the treatment of uric acid nephrolithiasis.” Archivio italiano di urologia, andrologia : organo ufficiale [di] Societa italiana di ecografia urologica e nefrologica vol. 82,3 (2010): 145-8.

Della Guardia, Lucio et al. “Diet-induced acidosis and alkali supplementation.” International journal of food sciences and nutrition vol. 67,7 (2016): 754-61. doi:10.1080/09637486.2016.1198889

Ferraro, Pietro Manuel et al. “Risk of Kidney Stones: Influence of Dietary Factors, Dietary Patterns, and Vegetarian-Vegan Diets.” Nutrients vol. 12,3 779. 15 Mar. 2020, doi:10.3390/nu12030779

Frassetto, Lynda, and Ingrid Kohlstadt. “Treatment and prevention of kidney stones: an update.” American family physician vol. 84,11 (2011): 1234-42.

He, Feng J et al. “Effects of potassium chloride and potassium bicarbonate on endothelial function, cardiovascular risk factors, and bone turnover in mild hypertensives.” Hypertension (Dallas, Tex. : 1979) vol. 55,3 (2010): 681-8. doi:10.1161/HYPERTENSIONAHA.109.147488

Kamphuis, Guido Maarten et al. “Method of alkalization and monitoring of urinary pH for prevention of recurrent uric acid urolithiasis: a systematic review.” Translational andrology and urology vol. 8,Suppl 4 (2019): S448-S456. doi:10.21037/tau.2019.05.01

Maalouf, Naim M et al. “Metabolic basis for low urine pH in type 2 diabetes.” Clinical journal of the American Society of Nephrology : CJASN vol. 5,7 (2010): 1277-81. doi:10.2215/CJN.08331109

Minich, Deanna M, and Jeffrey S Bland. “Acid-alkaline balance: role in chronic disease and detoxification.” Alternative therapies in health and medicine vol. 13,4 (2007): 62-5.

Pizzorno, Joseph et al. “Diet-induced acidosis: is it real and clinically relevant?.” The British journal of nutrition vol. 103,8 (2010): 1185-94. doi:10.1017/S0007114509993047

Rahman, Fakhri et al. “Effect of citrus-based products on urine profile: A systematic review and meta-analysis.” F1000Research vol. 6 220. 6 Mar. 2017, doi:10.12688/f1000research.10976.1

Schwalfenberg, Gerry K. “The alkaline diet: is there evidence that an alkaline pH diet benefits health?.” Journal of environmental and public health vol. 2012 (2012): 727630. doi:10.1155/2012/727630

Taylor, E N, and G C Curhan. “Fructose consumption and the risk of kidney stones.” Kidney international vol. 73,2 (2008): 207-12. doi:10.1038/sj.ki.5002588