What to Know About Acidic Foods
People measure acidity using the pH scale. This scale assesses whether something is an acid (acidic), neutral, or a base (alkaline).
- Acidic: 0–6.9
- Neutral: 7
- Alkaline: 7.1–14
The lower the number on the pH scale, the more acidic a substance is.
Acidity in the body
Researchers state that without underlying conditions that may affect the body’s acid-base balance, the body’s pH generally sits between 7.35 and 7.45. Numerous processes, like respiration and kidney function, work to maintain the body’s pH.
Acidity levels can be higher or lower in certain parts of the body. For example, the pH of stomach acid is around 1.5–2.0, which is important for digestion.
Acidity in foods
The United States Department of Agriculture states that acidic foods have a pH equal to or less than 4.6.
Potential renal acid load
Another factor to consider with acidic foods is their potential renal acid load (PRAL). PRAL refers to a food’s ability to influence the release of acids or alkalis in the body.
Certain foods, known as acid precursor foods, can promote the release of acids into the bloodstream. Other foods, like fruit, have alkalizing effects on the body even though their acid content may be high.
Foods that are alkalizing have a negative PRAL, but acid precursor foods have a positive PRAL.
Some foods have a high acidic content, and some elevate acid levels in the body.
Fruits that are high in acid include:
Many fruits have a high acid content. However, acidic foods do not necessarily have acidic effects on the body. Many fruits actually have alkalizing effects on the body, meaning they reduce the body’s acid levels.
In general, vegetables are not high in acid. In fact, many vegetables have a negative PRAL and an alkalizing effect on the body, depending on how people prepare them.
Some cooked vegetables with a negative PRAL include:
- sweet potatoes
Some raw vegetables with a negative PRAL include:
- curly lettuce
Certain drinks can be high in acids like phosphoric, citric, and malic acid. These drinks can include:
- energy drinks
- fruit and tomato juices
Foods with a positive PRAL, and therefore, an acidic effect on the body, include:
- some cheeses
- some grains, like oat flakes or cooked white rice
While acidic foods have their place in a balanced diet, consuming high amounts may have certain health effects.
The same review also shared that an acidic diet could increase the risk of other conditions, such as:
However, a diet’s contribution to these and other chronic conditions is a complex topic. For example, fruits may be high in acid, but they’re also high in dietary fiber, which can help people manage blood sugar and reduce the risk of conditions like type 2 diabetes. More research is necessary on the potential links between acidic foods and chronic conditions.
While the potential benefits and risks of acidic foods need more study, people with certain existing health conditions may want to limit their intake.
According to the National Institute of Diabetes and Digestive and Kidney Diseases, people with gastroesophageal reflux disease (GERD) may want to limit or avoid acidic foods. These foods may trigger or worsen GERD symptoms like heartburn or nausea.
In addition, a 2015 study showed that acidic beverages can contribute to dental erosion. People with dental erosion may wish to avoid acidic beverages to prevent further damage to their teeth.
Here are a few other common questions about acidic foods. Sade Meeks, MS, RD, reviewed the answers.
What are acidic foods to avoid?
Foods that can elevate acid levels in the body include meat, eggs, beans, and some cheeses and grains. It may be better to avoid these foods or limit your intake.
Are bananas acidic?
No, bananas are not acidic. They actually have an alkalizing effect on the body, meaning they reduce acid levels.
Which fruits have the most acid?
Some of the most acidic fruits include lemons, limes, grapefruits, and oranges. Pineapples and grapes also have a high acid content.
Acidic foods may be high in acid or may promote the release of acids in the body.
Some research shows that a highly acidic diet may contribute to an increased risk of certain chronic conditions. However, the relationship between diet and these health conditions is complex and requires further study.
If you are concerned about the effects of acidic foods, talk with your doctor. They can help you understand potential risks and benefits based on your individual situation.