Alkaline food can be sorted by one number, the potential renal acid load, or PRAL. Rather than argue about the word "required" in the abstract, this article takes six dried fruits off the shelf, dates among them, and works out that number for each from public nutrient data. Then it asks what the score can and cannot tell you.
What the score measures
In 1995 Remer and Manz calculated the PRAL of frequently eaten foods. Their values ran from an average high of 23.6 mEq per 100g for certain hard cheeses, through 0 for fats and oils, to about -3 for fruits, fruit juices and vegetables. They also found a close link between net acid excretion and urine pH (r = .83), so the method can predict how a diet changes the acidity of urine (PubMed 7797810).
Gerry Schwalfenberg's 2012 review of the alkaline diet says foods can be categorised by their PRAL, and prints a table of them (PubMed 22013455). Parmesan sits at 34.2 and brown rice at 12.5. Banana is -5.5, spinach -14.0 and raisins -21.0. Fruits, vegetables and fruit juices are among the foods he describes as having a negative acid load. Dates are not on the list.
How the dried fruit numbers were worked out
A 2025 paper in the journal Nutrients prints the five-nutrient version of the formula (PubMed 41305607). PRAL equals 0.4888 × protein (g) plus 0.0366 × phosphorus (mg), minus 0.0205 × potassium, 0.0125 × calcium and 0.0263 × magnesium (all mg). Feed it the SR Legacy records in USDA FoodData Central for 100g of each fruit, including Deglet Noor, a Tunisian and Algerian variety, and Medjool, and you get the figures below. They are my own arithmetic on those records, not values from a study.
| Dried fruit (FDC record) | PRAL per 100g | PRAL per 30g |
|---|---|---|
| Deglet Noor dates (171726) | -11.6 | -3.5 |
| Medjool dates (168191) | -13.3 | -4.0 |
| Dark seedless raisins (168165) | -11.8 | -3.5 |
| Dried figs (174665) | -13.7 | -4.1 |
| Prunes (168162) | -13.0 | -3.9 |
| Dried apricots, sulfured (173941) | -21.1 | -6.3 |
Potassium does most of the work. Deglet Noor dates carry 656 mg of it per 100g in that record, Medjool 696 mg and the dried apricots 1160 mg. Protein and phosphorus, the two terms on the acid side, are small in all six. Protein runs from 1.81g for Medjool to 3.39g for the apricots.
Leave out the apricots and the other five fall between -11.6 and -13.7. The apricots stand apart.
Why the raisin numbers disagree
The formula gives -11.8 for raisins, while Schwalfenberg's table lists -21.0. Both come from the same kind of sum. His table takes its values from Remer and Manz's 1995 paper, and a 2013 review by Scialla and Anderson gives the equation Remer used: the same five nutrients, with the coefficients rounded (PubMed 23439373). What differs is the nutrient data fed in, and that review notes that PRAL is dependent on accurate nutrient composition databases. So treat any single PRAL figure as an estimate, and compare foods within one data set rather than across two.
Is alkaline food required, then?
The score is about urine. Blood is a different matter. Schwalfenberg describes serum pH as tightly controlled at about 7.4, in a slightly alkaline range of 7.35 to 7.45, with the kidneys and the lungs as the main ways the body keeps it there. Urine, he notes, can run from acid to alkaline depending on what the body needs to balance. His conclusion is that alkaline diets result in a more alkaline urine pH, and that there is no substantial evidence this improves bone health.
Fenton and colleagues came to a similar view in 2011. Alkaline diets and products, they write, are marketed as a way to help the body regulate its pH. Of 238 studies they found, 55 met their inclusion criteria, and they judged the evidence with Hill's criteria for causality. No study revealed a biologic mechanism working at physiological pH, and they found no evidence that an alkaline diet is protective of bone health (PubMed 21529374).
So "required" is too strong a word for what a PRAL score does. What Schwalfenberg's review does back is eating more fruit and vegetables, which would improve the potassium-to-sodium ratio. He puts that ratio at about 10 to 1 in earlier diets and 1 to 3 in the modern one.
Putting dates on the plate
The NHS says a 30g portion of dried fruit, such as currants, dates, sultanas and figs, counts as 1 of your 5 A Day. It should be eaten at mealtimes, not as a snack between meals, to reduce the impact on teeth. That is why the table above gives a 30g column.
Soft Mazafati dates come from Bam in Kerman province, Iran. They are dark and very soft, need refrigeration, and are cold-stored so they are sold all year. Kurma Mazafati Malaysia is a site about this variety.
The video below, from the YouTube channel AbuAyyash Farms, is titled "Amazing Medjool Dates Fruit Farming and Factory - Artificial Intelligence Date Processing Technology".
Before you change how you eat
This article is general reading, not personal advice. The NHS says that anyone with a medical condition or on a special diet for their health should talk to a GP or a healthcare professional before making changes to their lifestyle.
Kurma Distributor's about page describes retail and wholesale pricing, delivery across Malaysia and customer service over WhatsApp. The contact form is not available at the moment, so the contact page points to WhatsApp at +60 17-312 2220 for quotes. Other articles on dates are on the Kurma Distributor blog.