Is Tomato Acidic or Alkaline?
Tomato (fresh) is alkaline: Negative PRAL: alkalizing after digestion. Alkaline, even though they taste sour. Fresh tomatoes have a PRAL of −4.2 per 100 g, and tomato paste is even strongly alkaline at −21.2.
Classification
Fresh off the vine, a tomato is alkaline at −4.2 because it is almost entirely water with potassium and has hardly any protein or phosphorus. Dried, it reaches −53.8 because the water is gone. Two medium tomatoes totaling 200 g add about −8, which more than makes up for a slice of Tilsit cheese in a sandwich.
In the Vegetables & Salad category, tomato (fresh) ranks #50 of 110, sorted from alkaline to acid-forming. More alkaline options include White cabbage (−4.2), Romaine lettuce (−4.4), Lettuce, green (−4.4). More acid-forming are Zucchini (−4.1), Horseradish (−4.1), Okra (−4.1).
Acidic or alkaline: PRAL, not pH
On this site, acidic and alkaline refer to the PRAL (potential renal acid load). It estimates what a food leaves behind once it has been digested: a positive value is acid-forming, a negative value is alkalizing. That is different from the pH of the food itself: a lemon tastes sour, yet its PRAL is −4.0, so it is alkalizing. Your diet does not change your blood pH. It does change how much acid your kidneys have to deal with.
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Frequently Asked Questions
Is tomato acidic?
It depends on what you mean by acidic. The pH describes the food itself, for example how sour it tastes. The PRAL describes what it leaves behind after digestion: Tomato (fresh) has a PRAL of −4.2 per 100 g, so it counts as alkaline in your daily acid-base balance.
How much tomato do I need for a noticeable effect?
Two medium tomatoes (150 g) of tomato adds −6.3 to your daily balance. For comparison: an egg is around +5.4, a slice of cheese around +6. So one serving of tomato roughly offsets one of them.
Why is tomato alkaline even though it is not a typical alkaline food?
The PRAL depends on the minerals left over after digestion, not on taste or pH. Tomato provides more potassium, magnesium and calcium than phosphorus and protein, so the balance is negative (−4.2).
Tomato logged, balance checked.
Basentracker adds up every meal automatically and shows whether your day is in the alkaline range. The same values as on this page, all 977 foods, photo scan, recipes.
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Compare all Vegetables & Salad: Vegetables & Salad table. Common questions are answered in Acidic or Alkaline?, and the PRAL calculator adds up a whole meal.
Source: Basentracker food database (PRAL according to Remer & Manz, calculated from protein, phosphorus, potassium, magnesium and calcium per 100 g). This information does not replace medical advice.