"Alkaline food is required" sounds like one simple rule. It hides a question, though: required for which part of the body? Your body runs several very different pH levels at once, and food reaches only some of them. Once you see where each one sits, the alkaline idea gets much easier to judge, and so does the place of a few dates on your plate.
The pH levels your body keeps
A 2012 review by Gerry Schwalfenberg (PubMed 22013455) walks through them one by one. Blood is the strict one. Human life, the review says, requires a tightly controlled serum pH of about 7.4, held in a slightly alkaline range of 7.35 to 7.45.
The stomach sits at the other end, at pH 1.35 to 3.5, which the review links to digestion and to protection against microbes. Skin is acidic too, at pH 4 to 6.5, with a gradient from about 4 at the outer layer to 6.9 at the base. Urine is the odd one out. Its pH may swing from acid to alkaline, depending on what the body needs to balance its internal environment.
So the one pH the review calls tightly controlled, and required for life, is the blood range. The pH that varies with what the body has to balance is the urine.
Where food actually shows up
Diet leaves its mark in the urine. Remer and Manz worked out a score for this in 1995 (PubMed 7797810), called the potential renal acid load, or PRAL. A positive score means a food adds acid for the kidneys to clear. A negative one means it leaves an alkaline surplus.
Their numbers ran from an average high of 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. They also found that net acid excretion tracked urine pH closely, with a correlation of r = .83.
Schwalfenberg's review lists more foods. Raisins score −21.0, spinach −14.0 and banana −5.5. Brown rice comes in at 12.5 and rolled oats at 10.7. Grain products, meats, dairy and fish carry relatively high acid loads in his summary, while fruits, vegetables, fruit juices and potatoes carry negative ones.
So is alkaline food required?
Not in the sense the slogan suggests. The review's conclusion is that alkaline diets make the urine more alkaline, and that there is no substantial evidence this improves bone health. That is a long way from "required".
The same review does make one point worth keeping. It notes that since the agricultural revolution, and more so with industrialization, the ratio of potassium to sodium in the diet has reversed, from about 10 to 1 to about 1 to 3. More fruit and vegetables, it says, would improve that ratio. You don't need a pH strip for that. You need more plants on the plate.
Where dates fit on the scale
Dates are not in the review's table, and the 1995 abstract gives no figure for them either. What we can do is put their nutrient numbers next to raisins, the strongest negative scorer in the fruit list. USDA FoodData Central (SR Legacy, 2019) gives these values per 100g:
- Deglet Noor dates (FDC 171726): potassium 656mg, phosphorus 62mg, protein 2.45g, sodium 2mg.
- Medjool dates (FDC 168191): potassium 696mg, phosphorus 62mg, protein 1.81g, sodium 1mg.
- Dark seedless raisins (FDC 168165): potassium 744mg, phosphorus 98mg, protein 3.3g, sodium 26mg.
Potassium is one of the minerals counted on the alkaline side of the Remer formula, and phosphate sits on the acid side. Both date records are high in potassium and very low in sodium. Read the figures for what they are, not as a PRAL score.
Deglet Noor is the golden, semi-dry date from Tunisia and Algeria, often sold on the stem as kurma tangkai. Medjool is the large, very soft one with a caramel taste. Mazafati comes from Bam, in Iran's Kerman province, and is a dark, very soft date that needs refrigeration. Kurma Mazafati Malaysia is a site about that one variety.
A sensible portion
The NHS counts a 30g portion of dried fruit, and it names dates, as one of your 5 A Day. It adds that dried fruit should be eaten at mealtimes, not as a snack between meals, to reduce the impact on teeth. A 30g portion of dates eaten with lunch, next to a vegetable dish, fits that advice better than a handful in the afternoon.
Deglet Noor has 282 kcal per 100g in the FDC record, so the 30g portion comes to roughly 85 kcal. Worth knowing if you are watching your intake.
From palm to pack
The video below, from AbuAyyash Farms, follows Medjool dates through farming and a packing factory.
Getting dates in Malaysia
Malaysia has no commercial date-growing trade, so every date sold here is imported. The Dates Supplier about us page lists prices for retail and wholesale buyers, delivery across Malaysia and customer service over WhatsApp. For a quote, message the WhatsApp number on the contact page. More articles on dates are on the Dates Supplier blog.
This article is general information about food and is not medical advice.