Most writing about alkaline pH food stops at a list of good and bad foods. A more useful question is what actually moves when people change what is on the plate. Four research groups have put numbers on it, in trials that cut or swapped meat for anywhere from one week to two months, and in people who had been vegan for at least a year. Their results show where the change turns up, where it doesn't, and why a fruit like dates gets mentioned at all.
How the acid load of a diet is scored
Gerry Schwalfenberg's 2012 review (PubMed 22013455) says foods can be categorized by their potential renal acid load, or PRAL. Scialla and Anderson's 2013 review (PubMed 23439373) gives the equation, adapted from Remer: 0.49 × protein (g) + 0.037 × phosphorus (mg) − 0.021 × potassium (mg) − 0.026 × magnesium (mg) − 0.013 × calcium (mg). In a 1995 paper (PubMed 7797810), Remer and Manz calculated PRAL values from an average 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. Scialla and Anderson list cheese, meat, eggs and grains among the common foods that impart a high dietary acid load, while fruits and vegetables provide alkali.
Four weeks, vegan against meat-rich
At the University of Freiburg in Germany, Müller and colleagues randomly assigned 45 people who normally ate meat to a vegan diet (23 people) or a meat-rich diet (22 people) for four weeks, with the two diets matched for calories (PubMed 34639299). After three weeks the median PRAL score was −23.57 in the vegan group and 18.78 in the meat-rich group. The authors put the gap down to lower phosphorus and protein intake on the vegan side.
That is a gap of more than 40 points between the two diets. It is also a score worked out from what people ate, not a reading taken from their bodies.
Seven days in a row, or two
A trial at Arizona State University (Cosgrove and Johnston 2017, PubMed 28677099) asked healthy adults who ate meat to go vegan for seven days in a row, or on two or three spaced-out days over one week. Dietary PRAL scores fell in both groups. Urine pH over 24 hours rose only in the seven-day group, by 0.52 on average, against −0.02 for the part-time group.
The score on paper moved fast. The urine needed the change to be steady.
Vegans of a year or more in Berlin
Penczynski and colleagues, with Thomas Remer among the authors, collected 24-hour urine from 34 vegans and 35 omnivores in Berlin, each of whom had kept to their diet for at least a year (PubMed 36364731). Here the acid load was measured in the urine itself rather than estimated from food records. The vegans' urinary PRAL was lower by 34.5 mEq a day on average, and their urine pH was higher. The authors also note that the omnivores, who ate moderate amounts of protein, had a rather low acid load themselves.
What did not change: the blood
The SWAP-MEAT trial at Stanford (PubMed 39514692) had 36 generally healthy adults eat at least two servings a day of either plant-based meat alternatives or animal meat, for eight weeks each in turn. During the plant-meat phase, urine pH was 0.3 units higher on average and urine sulfate was lower. Serum bicarbonate, measured in the blood, did not differ between the two phases.
That matches Schwalfenberg's description. Human life requires a tightly controlled serum pH of about 7.4, within 7.35 to 7.45, while urine may vary from acid to alkaline depending on the need for balancing the internal environment.
So is alkaline food "required"?
Read together, these papers show that diet changes the acid load you take in and the pH of your urine, and that the urine can shift within a week. Of the four abstracts, only SWAP-MEAT reports a blood measure, and its serum bicarbonate did not differ. Two of the trials changed the whole diet and the third swapped one food group, meat, for a plant version. The Berlin paper was not a trial at all: it compared people who already ate differently. None of them tested a single food on its own.
Where dates come in
Dates sit on the fruit side of that equation. USDA FoodData Central lists 100g of Deglet Noor dates (FDC 171726) at 2.45g protein, 62mg phosphorus, 656mg potassium, 43mg magnesium and 39mg calcium. Through the Scialla equation that comes to about −11.9 per 100g, mostly because of the potassium. A 30g portion works out at about −3.6.
On those numbers, 30g of dates is small next to the 40-point gap between the two Freiburg diets, and the authors put that gap down to lower protein and phosphorus intake. FDC also lists Deglet Noor at 282 kcal per 100g, so dates bring energy along with the potassium.
The NHS names dates with currants, sultanas and figs: a 30g portion of dried fruit counts as 1 of your 5 A Day, but should be eaten at mealtimes, not as a snack between meals, to reduce the impact on teeth.
About Pengedar Kurma Malaysia
The about page says the site handles everything from retail purchases to wholesale supply (runcit hinggalah bekalan borong), with orders sent safely across the country. Enquiries, quotes and orders go through WhatsApp, and the number is on the contact page. Other date articles are on the blog. A link kept from the earlier version of this post points to Kurma Mazafati Malaysia.
The video below is from the YouTube channel AbuAyyash Farms, titled as a look at Medjool date farming and a date processing factory.
This article is general information about diet research, not personal advice. If you have a health condition or take regular medication, speak to your doctor before making big changes to what you eat.