Foods with a pH below 4.6 are considered highly acidic. This category includes many citrus fruits, plums, grapes, pomegranates, and several other fruits. Tomatoes, which are botanically fruits, are also acidic.

Understanding Acidity

The pH scale measures whether a substance is acidic, neutral, or alkaline (basic).

• A pH of 0 signifies extreme acidity.

• A pH of 7 is neutral.

• A pH of 14 represents extreme alkalinity.

For example, battery acid is highly acidic at a pH of 0, while liquid drain cleaner is very alkaline at pH 14. Pure distilled water is neutral with a pH of 7.

Similarly, different parts of the human body have varying pH levels. Ideal blood pH ranges from 7.35 to 7.45, which is slightly alkaline. The stomach maintains a pH around 3.5, aiding proper digestion.

Foods and Drinks High in Acid

If you suspect acidity issues, adjusting your diet might help alleviate symptoms. Acidic foods are defined as those with a pH of 4.6 or lower.

Some foods that tend to increase acidity in the body and may need to be limited or avoided include:

• Grains

• Sugar

• Certain dairy products

• Fish

• Processed foods

• Fresh and processed meats (like corned beef and turkey)

• Sodas and sugary drinks

• High-protein foods and supplements

There is limited scientific evidence linking animal proteins and dairy to chronic diseases through pH imbalance. Ongoing research may clarify this connection or reveal other health benefits from reducing animal product consumption.

Acidic Fruits and Juices

According to Clemson University, here are some fruits ranked from most to least acidic, with their pH ranges:

• Lemon juice (pH: 2.00–2.60)

• Limes (pH: 2.00–2.80)

• Blue plums (pH: 2.80–3.40)

• Grapes (pH: 2.90–3.82)

• Pomegranates (pH: 2.93–3.20)

• Grapefruits (pH: 3.00–3.75)

• Blueberries (pH: 3.12–3.33)

• Pineapples (pH: 3.20–4.00)

• Apples (pH: 3.30–4.00)

• Peaches (pH: 3.30–4.05)

• Oranges (pH: 3.69–4.34)

• Tomatoes (pH: 4.30–4.90)

Citrus fruits generally have a low pH, making them acidic. These, along with other acidic foods, can worsen symptoms for people with upper gastrointestinal issues such as ulcers or acid reflux.

Remember that fruit juices are also acidic. To protect your teeth, it’s advisable to drink fruit juices through a straw to minimize direct contact with your teeth.

If fruit doesn’t trigger digestive discomfort, it remains a healthy daily choice and has been shown to lower the risk of chronic diseases. Despite their initial acidity, most fruits have an alkalizing effect on the body.

Fresh Vegetables and Their pH

Most fresh vegetables are not acidic. Here are some examples with their pH values:

• Sauerkraut (pH: 3.30–3.60)

• Cabbage (pH: 5.20–6.80)

• Beets (pH: 5.30–6.60)

• Corn (pH: 5.90–7.50)

• Mushrooms (pH: 6.00–6.70)

• Broccoli (pH: 6.30–6.85)

• Collard greens (pH: 6.50–7.50)

Acidic Beverages

You might want to avoid drinks high in phosphorus, such as beer or hot chocolate made from powdered mixes. Mineral waters or sparkling waters are good alternatives. If you consume alcohol, choosing red or white wine, which are lower in phosphorus, might be better.

Low-Acid Foods

While some claim that a more alkaline diet benefits health, research published in the Journal of Environmental and Public Health found no conclusive evidence that it improves bone health. However, an alkaline diet may help reduce muscle loss, improve cognitive function, and promote longevity.

Some alkalizing or neutral foods and beverages to include in your diet are:

• Soy products like miso, soybeans, tofu, and tempeh

• Unsweetened yogurt and milk alternatives

• Most fresh vegetables, including potatoes

• Most fruits

• Herbs and spices, excluding salt, mustard, and nutmeg

• Beans and lentils

• Certain whole grains like millet, quinoa, and amaranth

• Herbal teas

• Healthy fats such as olive oil, avocados, nuts, and seeds

Effects of Consuming Excess Acidic Foods

Eating too many acid-producing foods, including protein and sugar, can increase urine acidity and may contribute to the formation of uric acid kidney stones.

Excessive acidity might also lead to bone and muscle breakdown, as bones release calcium to neutralize the blood’s acidity.

Some research links phosphoric acid—commonly found in dark sodas—to lower bone density, especially when such drinks replace milk, which is rich in calcium and protein. Too much acid might also raise the risk of cancer, liver issues, and heart disease.

Certain foods and drinks generate less acid than sodas or protein but still don’t offer the alkalizing benefits of most fruits and vegetables. Experts often disagree on precise food classifications.

Limiting these acid-producing foods may help protect your acid-base balance and overall health:

• Corn oil

• Sweeteners like sugar, molasses, maple syrup, processed honey, and aspartame

• Salt

• Condiments such as mayonnaise, soy sauce, and vinegar

• Hard and processed cheeses

• Grains like corn, rice, and wheat

• Coffee

If you’re concerned about acid damaging your bones, small doses of sodium bicarbonate may help. Researchers at the University of California, San Diego, suggest taking less than 5 grams per dose.

Avoid taking sodium bicarbonate with meals, as it can disrupt digestion. Ensuring adequate intake of calcium, vitamin D, phosphorus, and magnesium can also help counteract acid’s effects on bone health.

Prevention Strategies

Because bodily waste products tend to be acidic, researchers from the University of California, San Diego, recommend consuming alkaline-forming foods like fruits and vegetables at a ratio of 3:1 compared to acid-forming foods.

The pH of food before eating is less important than how it affects your body’s pH after digestion.

While urine that is too alkaline can occasionally occur, excessive acidity is more common in the U.S. This is largely due to high consumption of animal protein, sugar, and grains, along with widespread use of prescription medications.

Summary

The alkaline diet can be a healthy choice, likely because it emphasizes plant-based foods and limits processed items rather than drastically altering your body’s pH.

Increasing fruit and vegetable intake while cutting back on refined carbohydrates, sugars, and dairy may help balance pH levels, though more research is needed.

Regardless, a diet rich in plants and low in refined sugars offers numerous health benefits and may help prevent daily discomfort and long-term health problems.