Apples might not be the first thing that pops into your mind when you think of acidic foods, but they do have two different types of acids in them. The majority of the acid content in apples comes from malic acid, while the rest is the form of ascorbic acid — a more scientific name for vitamin C.
But if you're wondering if apples have acid in them because you have acid reflux or GERD, the good news is that they're still considered one of the non-acidic fruits safe for you to enjoy.
Apples contain malic acid and ascorbic acid, which is more commonly called vitamin C. But even though they contain acid, they're not considered one of the acidic foods that you have to avoid for heartburn or acid reflux.
Malic Acid in Apples
Malic acid is the primary type of acid in apples, according to an April 2013 issue of Tree Genetics & Genomes, and the concentration of malic acid in the different types of apples plays a huge role in how those apples taste. Wild apples have significantly more malic acid than farmed apples, even though the two varieties have similar amounts of sugar in the form of fructose and sucrose.
Although there hasn't been a lot of research into the health benefits of malic acid, there was one study that was published in an issue of Medicina Oral Patologia Oral y Cirugia Bucal in January 2013 that looked at how the acid affected people with a symptom called xerostomia, or dry mouth that's usually caused by a decrease in saliva.
The researchers found that after two weeks of supplementing with malic acid, the participants in the study had significantly increased saliva flow and relief from their symptoms. However, it's important to note that a malic acid spray was used during the study, so it's hard to say for sure whether apples could have the same effect.
Ascorbic Acid in Apples
Ascorbic acid, more commonly known as vitamin C, is another type of acid found in apples in significant amounts. As with malic acid, wild apples have more ascorbic acid than farmed apples. According to a report that was published in Food Chemistry in June 2017, that's because malic acid and ascorbic acid are positively correlated. In other words, when one type of acid increases, so does the other.
Another thing the report in Food Chemistry notes is that ascorbic acid is really high in immature apples, but as the fruit ripens, matures and gets bigger, the ascorbic acid content drops and the apple gets sweeter.
Because humans aren't able to make ascorbic acid, or vitamin C, on their own, it's important to get enough from the foods you eat, since vitamin C plays essential roles in your immune system, wound healing, skin health and protein metabolism.
Acid Reflux and Apples
If you have gastroesophageal reflux disease, also commonly referred to as GERD, some of the general dietary advice is to avoid acidic foods, like tomatoes and citrus fruits (lemons, oranges and limes) as well as any spicy foods, high-fat foods, caffeine and chocolate. But even though apples have malic acid and ascorbic acid in them, they're still considered one of the non-acidic fruits and are safe for those with GERD.
In fact, the International Foundation for Gastrointestinal Disorders recommends eating lots of non acidic fruits, like banana, melon, pear and apple for heartburn and acid reflux relief. Timing matters too, though. If you have heartburn or GERD, avoid eating anything within three to four hours before bedtime.
Of course, not all diet recommendations and lifestyle treatments are right for everyone, so if you have chronic digestive issues, it's always best to talk to your doctor about whether you should eat apples and what's right for you.
- International Foundation for Gastrointestinal Disorders: "Diet Changes for GERD"
- Medicina Oral Patologia Oral y Cirugia Bucal: "Effectiveness of Malic Acid 1% in Patients With Xerostomia Induced by Antihypertensive Drugs"
- Tree Genetics & Genomes: "Differences in Acidity of Apples Are Probably Mainly Caused by a Malic Acid Transporter Gene on IG16"
- Food Chemistry: "Comparative Assessment of Sugar and Malic Acid Composition in Cultivated and Wild Apples"
- National Institutes of Health Office of Dietary Supplements: "Vitamin C"
- Food Chemistry: "Variation of Ascorbic Acid Concentration in Fruits of Cultivated and Wild Apples"