Sour can be just as bad as sweet.
Sugar isn’t the only dental villain that undermines healthy teeth. Acidic, low-pH foods — sour candy, soft drinks, fruit juices — soften teeth. The result: enamel erosion and diminished tooth size. “Citric acid is the worst acid for your teeth,” says Martha Keels, DDS, chief of pediatric dentistry at Duke’s Children’s Hospital. “We’re seeing acid erosion every day.”
Dentists’ worst nightmare: ultra-sour, ultra-sticky, ultra-sugary kids’ candies such as Warheads and Toxic Waste. Even sour gummy vitamins can be culprits.
“These sour candies, when tested, have a really low pH, nearing battery acid,” says Robyn Loewen, DDS, a fellow in the American Academy of Pediatric Dentistry and a diplomate of the American Board of Pediatric Dentistry. “I liken it to an ice cube that’s been left on the counter. It melts the tooth.”

To make matters worse, children’s tooth enamel isn’t mature until a decade after their teeth erupt, Loewen says. Because it’s softer, “it’s more susceptible to the acid.”
Adults aren’t off the hook: Low pH fare includes sour mango Altoids and even sugar-free soft drinks.
If you’re going to consume highly acidic foods, do it during mealtime, Keels says. You’ll minimize the effects by consuming them along with other foods. Better yet, chew xylitol-containing gum, such as Ice Breakers Ice Cubes, Trident, or Orbit, Keels says. Xylitol fakes out bacteria and may even help prevent cavities. Gums containing Recaldent, such as Trident, will help teeth remineralize and resist tooth decay. Finally, brushing periodically with baking soda has been shown to neutralize acids in the mouth, which reduces the amount of acid-loving bacteria that cause cavities.