Acidic foods (with a pH of 4.6 or lower) are generally safe to consume as part of a healthy, balanced diet. However, they may trigger symptoms for people with certain health conditions.
With gastroesophageal reflux disease (GERD), acidic foods like tomatoes and citrus fruits can irritate the esophagus, leading to acid reflux. These foods may also irritate the bladder in people with interstitial cystitis (painful bladder syndrome).
What is pH?
The pH scale defines whether something is acidic, neutral, or alkaline. Its range is from 0 to 14, with zero (0) being the most acidic, 14 being the most alkaline, and 7 being neutral.
1. Citrus Fruits
Citrus fruits, such as lemons, oranges, and grapefruit, have an average pH between 3.0 and 4.3. The main compound responsible for their acidity is citric acid, which contributes to their tart flavor.
More sour fruits with higher levels of citric acid tend to be the most acidic, with pH levels as low as 2 in tart lemons and limes.
Other Fruits
In addition to citrus fruits,other acidic fruits include:
- Grapes: pH 2.8-3
- Plums: pH 2.8-3.4
- Strawberries: pH 3-3.9
- Blueberries: pH 3.1-3.3
- Raspberries: pH 3.2-4
- Apples:pH 3.3-4
- Peaches: pH 3.3-4
- Apricots: pH 3.3-4.8
- Pineapple: pH 3.2-4
- Prunes: pH 3.6-3.9
2. Tomatoes
Tomatoes contain citric and malic acid, which contribute to their acidity. On average, tomatoes have a pH between 4.3 and 4.9. Unripe tomatoes generally have a lower pH, while overripe tomatoes have a higher pH.
Commercially sold canned tomatoes often have a lower pH due to added lemon juice or citric acid. This allows for a milder heat treatment during processing while ensuring the tomatoes are safe from bacterial contamination.
Canned tomato paste and juice may have pHs as low as 3.5 and 4.1, respectively. Ketchup, made with tomatoes, sugar, and vinegar, is also acidic.
3. Coffee
Coffee is acidic, with a pH of 4 for lighter roasts and up to 4.3 for darker roasts. It contains several acids, the most concentrated of which are chlorogenic, quinic, and acetic acids.
In one study, people with regular gastroesophageal reflux (GER) symptoms had less heartburn and acid reflux when they replaced coffee with water.
4. Carbonated Drinks and Fruit Juice
Carbonated drinks and store-bought fruit juice often contain acid to add flavor and extend their shelf life. Phosphoric acid gives cola its tart taste, helps stop bacteria growth, and improves shelf life.
Citric acid in fruits adds a tangy flavor and acts as a preservative. Malic acid, naturally found in apples and cherries, is added to fruit drinks and teas to boost flavor and to sodas to make them taste sweeter.
The following beverages are the most acidic, with an average pH of:
- Lemon juice: pH 2.3
- Cranberry juice: pH 2.6
- Lemonade: pH 2.6
- Energy drinks: pH 3.1
- Other soda: pH 3.1
- Sports drinks and flavored water: pH 3.3
- Pineapple juice: pH 3.4
- Flavored tea: pH 3.5
- Apple juice: pH 3.6
- Orange juice: pH 3.9
5. Fatty Foods
Fatty foods may not be highly acidic but can worsen heartburn and acid reflux. They do this by relaxing the lower esophageal sphincter, which allows stomach acid to flow back into the esophagus.
Fatty foods to avoid include full-fat dairy products, fried foods, and fatty meats like bacon and sausage.
6. Yogurt
Yogurt is considered acidic, with an average pH between 4 and 4.4. During fermentation, the milk's lactose is converted to lactic acid, which decreases the pH.
However, studies show low-fat yogurt can help with acid reflux if it's not too sour. Its probiotics support digestion and relieve stomach discomfort.
Another study noted that yogurt, despite its acidity, doesn't lead to enamel erosion like some other acidic foods.
7. Alcohol
The fermentation process makes most types of alcohol very acidic. One study noted that whiskey and rum have pH values of 4.3 and 4.1, respectively. Red and white wine are also acidic, ranging from 3.1 to 3.5 pH. Beer is similarly acidic, averaging between 3.9 and 4.5 on the pH scale.
8. Pickled Foods
Pickled foods, such as cucumbers, sauerkraut, and olives, are typically preserved in a vinegar/acetic acid solution, giving them a highly acidic pH range of 3.4 to 4.2.
Do Certain Foods Neutralize Acid?
High-fiber foods, including whole grains, vegetables, legumes, and nonacidic fruits, can help aid digestion and reduce pressure on the lower esophageal sphincter. Certain fiber types may also help neutralize stomach acid, though more research is necessary.
One study notes that bananas, an alkaline fruit, can help reduce stomach acid and form a protective coating around the esophagus. Bananas are rich in pectin, a soluble fiber that helps food move through the digestive system, preventing excess acid production.
Other alkaline foods, like almonds, leafy greens, lean proteins, and oats, may also neutralize stomach acid.
Limited evidence suggests that licorice root and ginger may help reduce acid production. Licorice works by blocking enzymes involved in stomach acid secretion, while ginger helps through its anti-inflammatory properties.
High-Acid Food Swaps
To help reduce acid in your diet, consider these simple food swaps:
Try ...
Bananas and melons
Pesto or olive oil
See AlsoBest Foods For Gut HealthGrilled or baked meat
Low-fat yogurt
Healthy fats like avocado, olive oil, fatty fish, and nuts
Herbal teas or water
Instead of ...
Citrus fruits
Tomato sauce
Fried meats
Full-fat yogurt
Unhealthy fats like full-fat dairy, baked goods, and fried foods
Carbonated drinks
Conditions Associated With Acidity
Acid Reflux and GERD
Acidic foods can cause the lower esophageal sphincter to relax, allowing stomach acid to flow back into the esophagus. This irritates the lining of the esophagus and causes heartburn. Over time, this can progress into GERD, a more severe form of acid reflux.
Treatment typically includes lifestyle and diet modifications, such as avoiding trigger foods, particularly high-acid, fatty, and spicy foods.
Antacids, which neutralize stomach acid, and acid reducers are available over the counter (OTC) to help treat heartburn and acid reflux.
A Word From Verywell
Knowing your trigger foods is one of the first steps in managing acid reflux symptoms. Acidic foods, including coffee, carbonated beverages, and alcohol, are some of the most common trigger foods. Finding alternatives may help reduce future bouts of reflux.
— JONATHAN PURTELL, RDN, MEDICAL EXPERT BOARD
Interstitial Cystitis
Interstitial cystitis (IC) is a chronic condition that causes pressure or discomfort in the bladder and pelvic area. The exact cause is unknown, but it may be related to bladder lining issues, autoimmune disorders, or allergies.
Although research is limited, many people with IC find that acidic and spicy foods, alcohol, and caffeine can trigger bladder pain.
If you believe acidic foods are triggering your bladder pain, consider keeping a food diary to track your symptoms and food intake.
Prelief, which contains calcium glycerophosphate, is an antacid designed to neutralize food acids and may help improve symptoms in people with IC.
Dental Erosion
Dental erosion happens when acids wear away the hard parts of your teeth. Internal factors like acid reflux or vomiting and diet can cause it. Soft drinks, especially carbonated sodas, can significantly increase the risk of dental erosion. Highly acidic fruit juices and acidic snacks and sweets can also increase the risk of dental erosion.
Rinsing your mouth with water after eating or drinking acidic foods, using a straw, and drinking milk with meals can help protect your teeth from acidic damage. Chewing gum may also help prevent erosion by increasing saliva, which helps neutralize acids.
When to Talk to a Healthcare Provider
Speak with a healthcare provider or registered dietitian nutritionist if you're experiencing persistent symptoms like acid reflux, heartburn, or discomfort after eating certain foods. They can help identify the cause of your symptoms and suggest changes to your diet or recommend treatments.
If you think acidic foods contribute to heartburn, bladder pain, or another condition, keep a diary to track your symptoms and food intake. Share this information with your provider to help guide your treatment.
Summary
Acidic foods with a pH of 4.6 or lower can be part of a healthy diet but may worsen symptoms for people with conditions like acid reflux, heartburn, or bladder pain. High intakes of these foods can also lead to dental issues.
Common high-acid foods include tomatoes, citrus fruits, and carbonated sodas. Eating high-fiber foods like whole grains and bananas and alkaline options like leafy greens may help reduce acid. Over-the-counter antacids and acid reducers can also help manage symptoms.