With alkaline diets on the rise and the prevalence of acid reflux, many people avoid acidic foods.
However, there’s a difference between acid-forming foods and foods with an acidic pH. Acid-forming foods are those that promote acidity in your body. Conversely, not all foods with a low (or acidic) pH promote an acidic environment in your body.
If this sounds confusing, don’t worry. This article outlines the differences between acid-forming foods and those with an acidic pH, as well as the reasons why some people avoid these foods.
Here are 6 acidic foods, explained.
You’ve probably heard of alkaline diets, which are said to promote a non-acidic environment in your body. Although these diets aren’t typically based on sound science, you may still wish to reduce your intake of acid-forming foods.
Your body has a tightly controlled blood pH level of about 7.4, which is slightly alkaline or basic. This pH is maintained through mechanisms like breathing and urination.
However, the pH of different body parts varies significantly. For example, your stomach has a very acidic pH of 1.35–3.5 to break down the foods you eat (
Although blood pH is tightly regulated, the pH of your urine changes depending on the need to balance your body’s pH and is altered by what you eat.
Notably, foods have different potential renal acid loads (PRALs), which are measured by acid excretion in the urine or the acid load that the kidneys must excrete to maintain your body’s pH (
Dietary acid loads
In general, foods that carry a high dietary acid load include meat, cheese, soft drinks, and processed grains. Conversely, fruits and vegetables have a low dietary acid load and tend to be alkaline or basic in nature.
Western diets tend to be high in animal protein and other foods with high PRALs while low in fruits and vegetables (
On the one hand, diets that carry a low acid load, such as plant-based diets rich in vegetables and fruits, may help promote kidney and heart health. On the other, diets with a high acid load may have the opposite effect (
For this reason, it’s a good idea to limit foods with high PRALs and increase foods with low PRALs — especially vegetables and fruits.
The following items are some of the most popular foods with high dietary acid loads.
1. Soft drinks
Excess phosphorus, especially in the form of highly absorbable phosphoric acid, has been linked to adverse health effects.
2. Red meat and other animal proteins
3. Processed grains
4. Cheese and dairy products
Cheese, milk, and ice cream are high in phosphorus and contribute to a high dietary acid load (
Although dairy products like cheese and unsweetened yogurt are nutritious, a diet high in these products and low in plant foods may contribute to a high dietary acid load.
Western diets tend to be high in foods like meat, cheese, refined grains, and soda but low in vegetables and fruits. These factors contribute to a high dietary acid load, which is associated with several negative health outcomes.
Some foods have an acidic PH but don’t form acid in your body.
For example, citrus fruits and tomatoes have an acidic pH but low PRALs.
However, people with gastroesophageal reflux disease (GERD), which is characterized by heartburn and regurgitation, may avoid these foods. GERD affects about 20% of the U.S. population and is usually treated through dietary changes and medication (
Some foods, including those with an acidic pH, are known to increase symptoms of GERD. Thus, people with this condition tend to avoid them (
The following foods have an acidic pH (
5. Citrus fruits
Citrus fruits are considered reflexogenic, meaning that they cause or worsen reflux. As such, the National Institutes of Health (NIH) and American College of Gastroenterology (ACG) recommend that people with GERD avoid or reduce their intake of citrus fruits (
6. Tomato-based products
Tomato-based products like tomato sauce and salsa are some of the most common culprits of reflux symptoms.
The NIH and ACG likewise recommend that people with GERD avoid or reduce their intake of tomato products (
Keep in mind that people with GERD may tolerate raw tomatoes better than canned tomato products. This may be because some cooked tomato products like ketchup, tomato paste, and tomato sauce are more acidic than fresh tomatoes (23,
Yet, tomatoes are highly nutritious and a great source of lycopene, a powerful antioxidant linked to many benefits. Thus, you shouldn’t avoid tomato products unless these foods exacerbate reflux symptoms (
Tomatoes and citrus fruits have an acidic pH and may exacerbate reflux symptoms. However, these foods are nutritious and shouldn’t be eliminated from your diet unless they cause or worsen reflux.
Remember that there’s a difference between foods with an acidic pH and those that contribute to a high dietary acid load. Even though foods like lemons, limes, and tomato paste have an acidic pH, they’re considered alkaline because they have low PRALs.
Cutting back on high PRAL foods, such as soda and animal proteins, and replacing them with low PRAL foods, such as vegetables and fruits, is beneficial for disease reduction and overall health.
Keep in mind that these findings are based on dietary patterns that are very low in plant foods and very high in red meat, processed foods, and soda.
Although it’s beneficial to reduce your intake of acid-producing foods, items like cheese, yogurt, and red meat can have a place in a healthy diet. It’s the quantity of these foods and your overall diet quality that matter most.
If you have GERD, cutting out foods with acidic pHs may reduce reflux symptoms. Speak with your healthcare provider for advice on foods to eliminate.
Lowering your intake of certain acid-forming foods and increasing your intake of fresh produce may boost your health. Likewise, avoiding certain foods with an acidic pH may relieve GERD symptoms — but only if you have this condition.
Western diets tend to be high in foods that contribute to a high dietary acid load, which may harm your health. Reducing your intake of red meat, refined grains, cheese, and soda while increasing your intake of veggies and fruit may reduce the acid load of your diet.
If you have GERD, you may need to cut out foods with an acidic pH to alleviate your reflux symptoms. Still, many of these foods are perfectly healthy for people without GERD.
If you’re curious about lowering your dietary acid load or controlling your acid reflux by cutting out acidic foods, consult your healthcare provider for advice.