Yesterday, I was asked for information about Potential Renal Acid Load. This is usually abbreviated to PRAL.

Though PRAL is a precise calculation based on certain nutrient values in foods, it is not an exact measure. It is a shortcut measure to assess the affect of foods on the pH of the body. Experiments have shown that it is a reliable approximation of the acidifying or alkalizing effect of foods.

PRAL=0.49 Protein + 0.037 Phosphorous – 0.021 Potassium – 0.026 Magnesium – 0.013 Calcium.

This gives a positive value for acid forming foods and a negative value for alkaline forming foods. To ensure adequate nutrition it is important to chose a combination of foods with positive and negative PRAL values.

Many nutritionists and health-workers believe that a diet that has an overall negative PRAL total is healthiest.

For gout, an alkalizing diet reduces the chances of kidney stones forming, and helps to dissolve them if they form. It is important to also drink plenty of water to flush the dissolved salts from the kidneys.

A second effect of gout is that uric acid is more soluble in alkaline conditions. Though the pH of the blood is tightly regulated by the body, a tiny percentage increase in alkalinity is probably enough to dissolve slightly more uric acid. Again, it is vital to keep hydrated to ensure that the dissolved uric acid can be flushed from the body.

I have calculated PRAL values for all the foods in the USDA National Nutrient Database. I present these as tables for each food group in my Gout Food Section of my gout information website.

This post answers a short gout question in the gout diet section. If you still have questions about Potential Renal Acid Load, see my Questions page on how to get the best answers quickly.