Apple cider vinegar: What the experts say

— "People didn't really lose that much weight," Drayer says. "Only 2 to 4 pounds in three months over a placebo. That's only a third of a pound a week."

Johnston agrees the study showed "a very, very modest weight loss.'

"In fact, I would say most people who are on a diet for 12 weeks and only lose a couple of pounds aren't going to be very happy," she adds.

If you are using apple cider or other vinegars as one part of an overall plan, combining it with a healthy diet, portion control and exercise, it might help, Drayer says. She suggested using balsamic vinegar on salads, in a 4:1 ratio with oil, or adding it to sauces for poultry and fish.

"If you were doing all the other things to lose weight, it might give you a slight edge," Drayer says. "Also, if you're drinking it in water, that's good, as water makes you feel full."

"Sometimes, people get really excited to try something new, and then their other behaviors change, too," she adds. "So if this helps people be more careful overall, that's a good thing."

Teeth cleaning and whitening

"Some people like to use it to remove stains and whiten their teeth," according to one of many online articles touting apple cider vinegar for this purpose: "To try this, rub a small amount of apple cider vinegar onto your teeth with a cotton swab."

"I let out an audible gasp when I read about this!" says Chicago dentist and American Dental Association spokeswoman Alice Boghosian. "It made me cringe, to be honest with you. What are people doing?"

"You're putting acid on your teeth," Boghosian continues, "the last thing you'd want to do to promote oral health. What would be a healthier option is to brush your teeth twice a day for two minutes, with a whitening toothpaste with the ADA seal. That shows it's been tested to do what it's supposed to do."

Other articles promote rinsing your mouth with apple cider vinegar, soaking dentures with a diluted mixture or using it to clean a toothbrush.

"You just have to rinse off your toothbrush, get all the toothpaste out, and let it air out. That's all you have to do," Boghosian says. "Cleaning dentures or rinsing with vinegar is not a good idea. It too could put your teeth at risk. And just think how it might affect the metal on partial dentures."

A pH of 7 is neutral, explains Boghosian; anything less is acid. She said many of today's popular apple cider vinegars are in the 2 to 3 range -- about the same as stomach acid.

"Anything acidic which contacts your teeth will wear out the enamel, the protective coating, and that will cause cavities," Boghosian adds. "So, this is totally, completely wrong, unless you want to be paying more visits to your dentist."

Skin, hair and nails

Commonly suggested uses for apple cider vinegar across the internet include it's use as a treatment for skin infections and acne, fighting lice and dandruff, as a natural wart remover and as an anti-aging treatment.