One of the main duties of saliva is to neutralize acid in the mouth after eating. This neutral environment is necessary for a healthy mouth and body. There are several things that can make saliva too acidic.
Sjögren's syndrome is an autoimmune disease that affects the glands that produce moisture in the mouth. A dry mouth does not produce sufficient saliva, which means the pH of the saliva can become too acidic because there is not enough to dilute acids in the mouth.
Chemotherapy can damage the salivary glands so that they do not produce as much saliva as needed. This can lead to saliva that contains too much acid.
There are neutralizing agents like bicarbonate in saliva, but because smokers only produce about half as much saliva as nonsmokers, a smoker's saliva can easily become too acidic.
Acidic saliva can be caused if too many acidic foods are consumed. Some acidic foods and juices include citrus like orange juice, grapefruit, tomatoes and carbonated beverages. Cutting back on acidic foods can reduce the acidity in saliva.
Sugary foods, whether candy, pastries or soft drinks, basically add a food source to the bacteria in the mouth. Bacteria thrive on sugar and create an acidic byproduct in the saliva. The more acidic the saliva, the more mineral loss in the teeth.