Discover Why Alkaline Ph Food Is Recommended
“Alkaline pH food” sounds like a food with a high pH. In the research, foods are sorted by a number called the potential renal acid load, or PRAL, which Remer and Manz calculated for common foods in a 1995 paper in the Journal of the American Dietetic Association (PubMed ID 7797810). PRAL is worked out from a food’s nutrient content and estimates the acid the kidneys have to excrete after that food is eaten.
How the PRAL number is built
A 2012 review in the Journal of Environmental and Public Health by Schwalfenberg (PubMed ID 22013455) sets out the Remer formula in words: sulfate plus chloride plus 1.8 times phosphate plus organic acids, minus the sum of sodium, potassium, 2 times calcium and 2 times magnesium. The review puts fruits, vegetables, fruit juices and potatoes on the side with “a negative acid load”, while grain products, meats, dairy products and fish “have relatively high acid loads”.
In the 1995 paper the averages ran from 23.6 mEq per 100g for certain hard cheeses, through 0 for fats and oils, down to about -3 for fruits, fruit juices and vegetables.
A few foods from the table
The Schwalfenberg review prints a PRAL table taken from Remer’s work. Some of its values, in mEq per 100g:
| Food | PRAL |
|---|---|
| Parmesan cheese | 34.2 |
| Brown rice | 12.5 |
| Lean beef | 7.8 |
| Olive oil | 0.0 |
| Banana | -5.5 |
| Spinach | -14.0 |
| Raisins | -21.0 |
Raisins have the lowest score of any fruit in that table. Dates are not listed at all.
What an alkaline diet changes, and what it doesn’t
Blood pH is held tightly. The review gives it as about 7.4, in “a slightly alkaline range of 7.35 to 7.45”. Urine is different. The review notes that a low-carbohydrate, high-protein diet with its increased acid load “results in very little change in blood chemistry, and pH, but results in many changes in urinary chemistry.” Remer and Manz report a correlation of r = .83 between net acid excretion and urine pH, and Schwalfenberg’s conclusion opens with “Alkaline diets result in a more alkaline urine pH”.
The same conclusion is careful about what follows from that. It states that there is no substantial evidence that this improves bone health, and the abstract ends by saying further studies are warranted. An honest reading: eating this way moves urine pH, and the review treats most of the other benefits as things that “may” happen and need more study.
So why is it recommended?
The strongest argument in the review is about what an alkaline diet puts on the plate. It says that increased fruits and vegetables “would improve the K/Na ratio”, the balance of potassium to sodium. The review describes how that ratio has flipped: “K/Na previously was 10 to 1 whereas the modern diet has a ratio of 1 to 3”.
That lines up with ordinary public advice. The NHS Eatwell Guide says fruit and vegetables should make up “just over a third of the food we eat each day” and that “Most of us are not eating enough fruit and vegetables.” If the alkaline label gets someone to eat more of them, the useful part of the advice is the fruit and vegetables themselves.
Where dates sit
The review’s PRAL table does not list dates, so this article doesn’t give them a score. What USDA FoodData Central (SR Legacy) does show is their mineral content per 100g, next to the raisins that score -21.0:
| Per 100g | Potassium | Sodium | Protein |
|---|---|---|---|
| Medjool dates (FDC 168191) | 696 mg | 1 mg | 1.81 g |
| Deglet Noor dates (FDC 171726) | 656 mg | 2 mg | 2.45 g |
| Dark seedless raisins (FDC 168165) | 744 mg | 26 mg | 3.3 g |
On those numbers dates carry plenty of potassium and very little sodium, which is the K/Na balance the review cares about.
The NHS counts “a 30g portion of dried fruit, such as currants, dates, sultanas and figs” as 1 of your 5 A Day, and adds that dried fruit “should be eaten at mealtimes, not as a between-meal snack, to reduce the risk of tooth decay.” At 277 kcal per 100g for Medjool, a 30g portion is about 83 kcal.
Mazafati at the table
Mazafati comes from Bam in Kerman province, Iran. It is dark, very soft and high in moisture, and it needs refrigeration. It is cold-stored and sold year-round, so it can sit beside the fruit and vegetables in any month. FoodData Central has only a branded label entry for Mazafati, not an SR Legacy analysis, so the table above uses Medjool and Deglet Noor.
Mazafati Dates Exporter delivers across the country, as our about page says. Send questions or orders through the contact page. For Malay-language buyers, Green Diamond’s pages are at harga Kurma Ajwa Green diamond and Pembekal Kurma.
This article explains a food-labelling idea and the evidence behind it. It is general information, not medical advice.