Is it just another sketchy health fad, or is there really some benefit to be gained from drinking apple cider vinegar? Celebrities like Katy Perry swear by it (which may be the only thing your great grandma had in common with Katy Perry), and it's likely you already have a bottle of it already, buried in the back of your pantry. But can it really help control your weight, conquer diabetes, cure warts, flush away constipation, chase away the flu, and do the hundreds of other wonderful things its supporters preach about? Or is it really best used for homebrewed pickles and tangy marinades?

First of all, what is apple cider vinegar? It is made from the juice of crushed apples, to which is added bacteria and yeast to jump-start the fermentation process, in which the sugars from the apple juice turn into alcohol. Through a second fermentation process, the alcohol is turned to vinegar, by acidic acid-forming bacteria.

Can it help you lose weight? Sort of. Only one study on people was done, in Japan. 175 obese but healthy people were given either vinegar or water daily for 12 weeks. Their diets were similar. At the end of the study, those who used vinegar had lost slightly more weight. On average, the vinegar group lost 1-2 pounds over the 3-month period. They gained it all back after the study was over. The researchers noted that vinegar may turn on certain genes involved in breaking down fats, but more study is needed. In any scenario, it's no magical elixir: exercise and calorie control are still necessary.

The claims about apple cider vinegar as a diabetes fighter hold a little more weight. Research has shown that the vinegar blocks some of the digestion of starch, thereby preventing your blood sugar from rising as much. Again, the effect is minimal, and caution is advised. A common problem among diabetics is gastroparesis, a condition that slows stomach emptying, and research shows apple cider vinegar may make this problem worse.

One thing is for sure: if you do decide to partake of apple cider vinegar, be sure it is the unfiltered, unpasteurized kind. It will be cloudy, and contain a blob in the bottle. That's the “mother,” jam-packed with probiotics and other nutrients. These probiotics not only support immune functions, but can relieve constipation as well.

Do not drink it straight out of the bottle. (Sorry, Katy!) Apple cider vinegar is so acidic it can damage the enamel on your teeth, as well as your esophagus. Instead, just add a couple of teaspoons of it to a glass of water, once or twice a day.