The pH value tells you whether something is an acid, a base, or neutral.
- A pH of 0 indicates a high level of acidity.
- A pH of 7 is neutral.
- A pH of 14 is the most basic, or alkaline.
For example, battery acid is extremely acidic at 0, while liquid drain cleaner is very alkaline at 14. Pure distilled water is in the middle at 7. It’s neither acidic nor alkaline.
Just like different substances, different parts of the human body have different pH levels.
Your ideal blood pH is between 7.35 and 7.45, which is slightly alkaline. The stomach is typically acidic at a pH of 3.5, which helps to break down food properly.
The body tightly regulates its pH balance through a variety of mechanisms that involve multiple organs like the kidneys and lungs (
Although your diet may affect the pH of your urine, research generally suggests that consuming acidic or alkaline foods is unlikely to have a significant impact on the pH level of your blood (
In fact, increased levels of acid in the blood are usually indicative of an underlying health issue like diabetes that’s not well managed, lung disease, or kidney problems (
Still, some people may choose to limit foods high in acid to reduce their potential renal acid load (PRAL), which refers to the amount of acid your body produces from the foods you eat (
Foods that are considered acidic generally have a pH level of 4.6 or lower.
Foods that tend to cause more acidity in the body and that you may want to limit or avoid include (
- certain dairy products, including cheese
- fish and seafood
- high-sodium processed foods
- fresh meats and processed meats, such as corned beef and turkey
- certain starchy foods, such as brown rice, oat flakes, or granola
- carbonated beverages, such as soda, seltzer, or spritzers
- high protein foods and supplements with animal protein
Research supporting the connection between foods like animal protein and chronic disease due to a change in the body’s pH is limited.
New research may shed more light on this connection or expose other reasons why reducing animal products is beneficial for health.
Although most types of fruit are acidic, they’re considered alkalizing, meaning that they actually help reduce acid levels in the body (
This also means that they have a negative PRAL, which is a value used to estimate the amount of acid produced during digestion for certain foods.
Here is the PRAL for a 3.5-ounce (100-gram) portion of several popular fruits (
- limes: -0.4
- plums: -1.7
- green grapes: -2.4
- purple grapes: -1.9
- pomegranates: -8.1
- blueberries: -0.6
- pineapples: -1.1
- apples: -1.8
- peaches: -1.5
- oranges: -1.6
- tomatoes: -1.8
- raisins: -9.0
- blackberry: -1.0
- banana: -5.2
In fact, those with conditions like gastroesophageal reflux disease (GERD) are often advised to limit their intake of acidic foods, including citrus fruits like oranges, grapefruit, lemons, and limes (
Like fruits, vegetables are also considered alkalizing and can help reduce acid levels in the body.
Here is the PRAL for a 3.5-ounce (100-gram) serving of some common vegetables (
Carbonic acid, which is present in all carbonated beverages, including not only soft drinks but sparkling waters and spritzers, contributes to your total body acid.
If you want to lower your acidity, regular or filtered tap water is best.
When it comes to the benefits of a more alkaline diet, research published in the Journal of Environmental and Public Health says that no conclusive evidence suggests it improves bone health (
However, it may help limit muscle loss, strengthen memory and alertness, and help you live longer (
Some alkalizing (or neutral) foods and beverages you can incorporate into your diet include:
A diet that includes too many acid-producing foods, such as animal proteins, some cheeses, and carbonated beverages, can cause acidity in your urine as well as other negative health effects. This may cause a type of kidney stone called uric acid stones to form (
It’s been speculated that too much acidity can also cause bone and muscle deterioration. This is because bones contain calcium, which your body uses to restore your blood’s pH balance when it becomes too acidic (
However, keep in mind that research has turned up conflicting results on how acidic foods may affect bone and muscle health due to the variations in total diet among test subjects (
Additionally, consuming moderate amounts of foods high in acid as part of a healthy, balanced diet with plenty of fruits and vegetables is unlikely to cause muscle and bone loss or increase the risk of chronic disease (
Some evidence suggests that phosphoric acid, commonly found in darker sodas, is linked to lower bone density when it replaces milk, a calcium- and protein-rich beverage. Too much acidity may also increase your risk for cancer, liver problems, and heart disease (
Some foods and beverages produce less acid than sodas or protein, but they still don’t provide the major alkalizing effect that most fruits and vegetables offer. Experts don’t always agree on the exact food lists.
Aim to limit these foods since they may be affecting your acid-base balance or affecting your health in negative ways (
- high-sodium condiments, such as soy sauce, steak sauce, barbecue sauce, and some salad dressings
- certain types of cheese, including mozzarella, Parmesan, and brie
- grains, such as corn, rice, and wheat
Eating a well-rounded diet rich in fruits, vegetables, whole grains, and healthy fats is a great way to help balance your dietary acid load and support overall health.
Enjoying plant-based proteins like beans, lentils, tofu, and tempeh in place of animal proteins in your diet from time to time can also be beneficial.
Nutrient-dense foods like cow’s milk can also supply several important nutrients to promote bone health, including calcium, vitamin D, phosphorus, and magnesium (
Researchers at the University of California in San Diego suggest eating more sources of alkaline-producing foods, such as fruits and vegetables, at a 3-to-1 ratio (15).
The pH of a food before you eat it is less important than the amount of acid or alkaline produced with digestion and metabolism of that food.
While rare, it’s possible for the urine’s pH to be too alkaline. However, in the United States, too much acid tends to be a more common problem. This is because the average diet contains more animal protein and grains but not enough fruits and vegetables.
Higher rates of prescription drug use also contribute to the problem.
Because the body closely regulates its pH balance through a series of complicated mechanisms, following an alkaline diet is unlikely to significantly impact blood pH levels for most healthy adults.
Still, a balanced diet that includes more fruits, vegetables, dairy milk and yogurt, more plant protein sources and limits processed foods may be helpful to maintain normal acid/base balance and overall health.
Eating more fruits and vegetables and limiting animal products and high-sodium processed foods may or may not help balance pH levels within your body.
Moving toward a more plant-based eating plan has been shown to reduce the risk of chronic illness.