Acid/alkaline ash diets: time for assessment and change

Area of Science:

• Nutrition Science
• Biochemistry
• Urology

Background:

• The acid-alkaline ash hypothesis suggests foods leave a metabolic residue affecting urine pH.
• Dietary choices influence the body's acid-base balance, impacting physiological processes.
• Understanding diet's effect on urine pH is crucial for metabolic health assessment.

Purpose of the Study:

• To critically review the assumptions and validity of acid/alkaline ash calculations for predicting urine pH.
• To compare the potential urine pH effects of omnivore, lacto-ovo vegetarian, and vegan diets.
• To identify limitations in current methods for assessing diet's impact on acid-base balance.

Main Methods:

• Acid/alkaline ash calculations were performed for 7-day omnivore, lacto-ovo vegetarian, and vegan dietary patterns.
• Literature review on the history, assumptions, and mechanisms of the acid/alkaline ash concept.
• Analysis of difficulties and validity of food table calculations in predicting urine pH.

Main Results:

• Vegan diets exhibited the most alkaline potential, followed by lacto-ovo vegetarian diets, both significantly more alkaline than omnivore diets.
• The study highlights the significant influence of dietary patterns on urine pH.
• Current calculation methods are time-consuming and lack quantitative precision.

Conclusions:

• While diet demonstrably affects urine pH, existing calculation methods are insufficient for precise prediction.
• There is a need for the development of more accurate methods to calculate dietary effects on acid-base balance.
• Further research into refined dietary assessment tools for acid-base balance is warranted.