Most nuts are mildly acid-forming, not alkaline. Based on PRAL scores, which measure how much acid or base a food produces after digestion, nearly every common nut falls on the acid side of the scale. However, some nuts are so close to neutral that they’re often grouped with alkaline foods in popular diet guides, and the differences between nuts are significant enough to matter if you’re choosing between them.
How Nuts Get Classified as Acidic or Alkaline
When food is digested, the minerals left behind determine whether it pushes your body’s chemistry in an acidic or alkaline direction. Calcium, magnesium, and potassium leave alkaline residue. Protein, phosphorus, and sulfur leave acidic residue. Nuts are rich in both groups of minerals, but most contain enough protein and phosphorus to tip the balance slightly acidic.
The standard measurement for this is the PRAL score (potential renal acid load). A negative score means a food is alkaline-forming. A positive score means it’s acid-forming. Zero is neutral. For context, most fruits and vegetables score well into negative territory, while meat and cheese score highly positive. Nuts cluster in a narrow band just above zero.
PRAL Scores for Common Nuts
Here’s how popular nuts rank per one-ounce serving, from most acid-forming to closest to neutral:
- Black walnuts (dried): 3.88
- Cashews (raw): 2.49
- Pine nuts (dried): 2.44
- Brazil nuts: 2.26
- English walnuts: 1.57
- Pistachios (dry roasted): 0.61
- Pecans (dry roasted): 0.61
- Almonds: 0.60
Almonds, pecans, and pistachios sit closest to neutral at around 0.6 per ounce. This is why you’ll frequently see almonds described as “alkaline” in diet books and wellness content. They’re not technically alkaline-forming, but they’re so close to zero that they barely register as acidic. Compare that to a serving of cheddar cheese at roughly 7 to 10 on the PRAL scale, and you can see why nuts get a pass.
Chestnuts are one notable exception. They’re lower in protein and fat than other nuts and higher in starch and potassium, which gives them a PRAL score that dips into slightly negative territory. If you’re specifically looking for a nut that’s genuinely alkaline-forming, chestnuts are the strongest candidate.
Why Almonds Get Called Alkaline
Almonds appear on nearly every “alkaline foods” list online, and the reasoning comes down to their mineral profile. They’re one of the richest nut sources of calcium and magnesium, both alkaline-forming minerals. An ounce of almonds delivers about 76 mg of magnesium and 76 mg of calcium. That mineral density offsets most of their protein and phosphorus content, landing them at a PRAL score of just 0.6.
Many alkaline diet guides also classify almonds as alkaline because older food charts used a simpler “ash” method that didn’t account for absorption rates the way PRAL does. Under the ash method, almonds test as mildly alkaline. Under the more precise PRAL calculation, they’re barely acidic. Either way, almonds are about as close to neutral as a nut can get without crossing over.
Seeds Are Not More Alkaline Than Nuts
If you’ve been told to swap nuts for seeds to increase alkalinity, the data doesn’t support that. Pumpkin seeds score 7.72 per ounce and chia seeds score 4.07, making both more acid-forming than every common nut. Seeds tend to be denser in protein and phosphorus per serving, which drives their scores higher. Sunflower seeds and flaxseeds follow a similar pattern.
This doesn’t make seeds unhealthy. It just means that reaching for pumpkin seeds instead of almonds won’t move you in a more alkaline direction.
Does Soaking Nuts Make Them More Alkaline?
A popular claim in wellness circles is that soaking (or “activating”) nuts reduces their phytic acid, frees up minerals, and shifts them toward alkaline. A study that tested multiple soaking methods on almonds, hazelnuts, peanuts, and walnuts found this isn’t the case. Soaking for up to 12 hours in water or salt water reduced phytic acid by no more than 12%, and some samples actually showed a slight increase. More importantly, soaking led to lower overall mineral concentrations, particularly in chopped nuts where minerals leached into the water.
The ratio of phytic acid to minerals didn’t improve either, meaning the minerals that drive alkalinity weren’t made more available by soaking. If you prefer the taste or texture of soaked nuts, there’s no harm in it, but it won’t meaningfully change their acid-alkaline profile.
Putting Nut Alkalinity in Perspective
Even the most acid-forming nut on the list, black walnuts at 3.88, is mild compared to other protein sources. A serving of chicken breast scores around 7 to 8, and hard cheeses can reach 10 or higher. Adding a handful of almonds, pecans, or pistachios to a meal heavy in vegetables and fruit won’t pull your overall dietary acid load in a meaningful way.
Your kidneys regulate blood pH within a very tight range (7.35 to 7.45) regardless of what you eat. The practical benefit of choosing lower-PRAL foods like almonds or chestnuts over higher-PRAL options isn’t about changing your blood chemistry. It’s that foods with more alkaline-forming minerals tend to be rich in magnesium, potassium, and calcium, nutrients most people don’t get enough of. The mineral profile that makes a food “alkaline” also happens to make it nutritionally dense, which is the real reason these foods show up in healthy eating patterns.