The most alkaline foods are fruits, vegetables, and legumes, with dried dates, potatoes, kidney beans, and citrus fruits ranking among the strongest. Alkalinity in food is measured by something called the PRAL score (Potential Renal Acid Load), which reflects whether a food produces acidic or alkaline byproducts after your body digests it. A negative PRAL score means the food is alkaline-forming. The more negative the number, the more alkaline the food.
How PRAL Scores Work
PRAL has nothing to do with how a food tastes. It measures the balance of acid-producing and alkaline-producing minerals a food leaves behind once it’s been metabolized. Foods rich in potassium, calcium, and magnesium tend to reduce the amount of acid your kidneys need to filter out, earning them a negative PRAL score. Foods high in phosphorus and protein, like meat and cheese, generate more acid and score positive.
A PRAL of zero is neutral. Anything below zero is alkaline-forming, and anything above zero is acid-forming. Most whole plant foods fall on the alkaline side, while most animal products and grains fall on the acid side.
The Most Alkaline Foods by PRAL Score
Here are some of the most alkaline-forming foods, ranked from most to least alkaline per serving:
- Dates: PRAL of -13.7, making them one of the most alkaline foods you can eat
- Kidney beans: PRAL of -8.4
- Potatoes: PRAL of -6.9 per medium potato
- Soybeans: PRAL of -4.7
- Oranges: PRAL of -3.6
- Apricots: PRAL of -3.5
- Carrots: PRAL of -3.0 per medium carrot
- Avocados: PRAL of -2.4
- Apples: PRAL of -1.9
- Tofu: PRAL of -0.3
The pattern is clear: dried fruits, legumes, root vegetables, and fresh fruits dominate the alkaline end of the spectrum. Dates stand out dramatically, with a PRAL score nearly twice as negative as kidney beans.
Why Citrus Fruits Are Alkaline (Not Acidic)
This trips people up. Lemons, oranges, and grapefruits taste acidic because they contain citric acid. But once your body metabolizes them, they produce alkaline byproducts. The citric acid gets broken down during digestion, and what remains are alkaline minerals like potassium and calcium that reduce the acid your kidneys have to handle. Lemon juice, despite its low pH in a glass, has a negative PRAL score and is firmly alkaline-forming.
The takeaway: you can’t judge a food’s effect on your body’s acid balance by tasting it. What matters is the mineral residue left after digestion.
Vegetables With the Strongest Alkaline Effect
Root vegetables are consistently among the most alkaline foods. Potatoes score -6.9 per medium potato, which puts them in the same league as legumes. Carrots come in at -3.0 per medium carrot. Leafy greens like spinach, kale, and Swiss chard are also alkaline-forming, thanks to their high mineral content, particularly calcium, potassium, and magnesium.
As a general rule, the more colorful and mineral-dense a vegetable is, the more alkaline it tends to be. Starchy root vegetables often score better than you’d expect because of their potassium content. A baked potato with the skin on is one of the more alkaline things you can put on your plate.
What Alkaline Foods Actually Do in Your Body
Your blood pH stays tightly regulated between 7.35 and 7.45 regardless of what you eat. Your kidneys and lungs handle that. So when people talk about alkaline diets “changing your pH,” that’s an oversimplification. What alkaline foods actually do is reduce the workload on your kidneys by providing minerals that help neutralize dietary acids before your kidneys have to do the job themselves.
This distinction matters most for people with kidney concerns. Research from the American Society for Nutrition has highlighted accumulating evidence that eating more fruits and vegetables, specifically to reduce dietary acid load, slows the decline of kidney function in people with chronic kidney disease (CKD). In one trial, CKD patients who ate enough fruits and vegetables to cut their dietary acid load by half showed a slower decline in kidney function markers. A separate three-year study found that both supplemental bicarbonate and increased fruit and vegetable intake slowed kidney decline in patients with moderate-stage CKD.
There’s also evidence linking reduced acid load to improved markers of bone health and muscle function. One study in postmenopausal women with osteoporosis found that those who drank alkaline water alongside standard treatment had significantly greater improvement in spine bone density scores compared to those on standard treatment alone, though no difference was seen in hip bone density.
The Most Acidic Foods for Comparison
Knowing what’s alkaline helps more when you can see what’s on the other end. The most acid-forming foods are hard cheeses (Parmesan and cheddar top the list), processed meats, eggs, and grains like white rice and bread. These foods are high in phosphorus and sulfur-containing amino acids, which generate acid during metabolism.
This doesn’t mean acid-forming foods are inherently bad. Eggs and whole grains have clear nutritional benefits. But if you’re trying to shift the overall acid-base balance of your diet, the strategy is straightforward: eat more of the fruits, vegetables, and legumes listed above alongside whatever proteins and grains you already eat. You don’t need to eliminate acid-forming foods. You just need to balance them with enough plant foods to offset their acid load.
Practical Ways to Eat More Alkaline
You don’t need a specialized “alkaline diet” plan. The foods with the best PRAL scores are the same foods every nutrition guideline already recommends: fruits, vegetables, beans, and lentils. A few simple swaps make a noticeable difference in your overall dietary acid load.
Adding a side of kidney beans to a grain-heavy meal offsets much of the acid that rice or bread produces. Snacking on dates or dried apricots instead of crackers shifts the balance significantly, since dates alone have a PRAL of -13.7. Swapping a side of fries for a baked potato with skin gives you one of the most alkaline foods available from a single ingredient. Squeezing lemon over meals or into water adds alkaline byproducts despite the sour taste.
The people who benefit most from paying attention to dietary acid load are those with reduced kidney function, where even modest shifts toward more plant foods have shown measurable improvements in clinical trials. For everyone else, the practical reality is simpler: eating more fruits and vegetables is beneficial for dozens of reasons, and their alkaline-forming properties are one more item on that list.