The Truth Behind Common Apple Cider Vinegar Uses You've Likely Heard Before

Like many other widely-used natural treatments, apple cider vinegar carries a host of health claims attached to it, and no shortage of websites espousing these claims.

Just a simple Google search shows dozens of pages that reveal "20 Apple Cider Vinegar Uses and Benefits," "11 Reasons You Should Drink A Tbsp Of Apple Cider Vinegar Every Day," and "Apple Cider Vinegar: 13+ Health Benefits."

However, many of these lists come from sites known to promote harmful pseudoscientific concepts, such as vaccine refusal and use of supplements that haven't been studied. Apple cider vinegar is an extremely popular product, with videos about its use routinely getting millions of hits on YouTube.

So it's worthwhile to examine the claims made about it, see what the science is behind them - or if there is any, at all.

Claim: Apple cider vinegar will help you lose weight.

This is one of the most popular claims of apple cider vinegar proponents, and the article "The 5 Weight Loss Benefits of Apple Cider Vinegar" offers a typical spate of reasons why. The bulk of these claims stem from one study, done in 2009 in Japan. The research found "that swallowing two tablespoons of diluted apple cider vinegar twice a day with meals helped people lose about four pounds after 12 weeks," by blocking the gut's absorption of starch, according to Time magazine.

The study has never been repeated, and used a sample size of just 175 people. As Carol Johnston, a professor in the School of Nutrition and Health Promotion at Arizona State University, told Time, the effect would be "subtle," and any vinegar could be used. Johnston also advised not to drink the vinegar straight, as it's extremely acidic.

Claim: Washing your hair in an apple cider vinegar mix will eliminate dandruff and promote healthy hair.

Apple cider vinegar mixed with water and baking soda is often used as an alternative to shampoo, with the idea being that it's free of the chemicals that make up artificial hair products. It's not (nothing is), but does it work as a do it yourself (DIY) hair care product anyway?

Proponents believe that certain types of shampoo will strip your hair of natural oils, and cause dry skin and dandruff; but overuse of apple cider vinegar can have the same effect, due to its acidity. It does have certain anti-fungal properties, but nothing that regular shampoo doesn't have as well. It can also change the color of one's hair. In the end, using it as a shampoo alternative is simply a matter of personal preference and having the time to make it.

Claim: Apple cider vinegar can treat type-2 diabetes.

This ties into the claims about apple cider vinegar lowering blood sugar and insulin levels. There have been several studies of the link between it and blood sugar levels, but as Maria Pena, director of the Center for Weight Management in Syosset, New York, tells Healthline, "the results are mixed."

Two studies that looked into whether diluted apple cider vinegar could impact blood sugar had encouraging results, but both had sample sizes of around a dozen people, far too few to confirm a hypothesis. "Until a large, randomized control trial is done," Pena says, "it is difficult to ascertain the true benefits of taking apple cider vinegar [for diabetes]."

Claim: Cleaning your teeth with apple cider vinegar will make them whiter.

One of a number of apple cider vinegar claims made by pop health guru Dr. Oz is that it can whiten yellowed teeth. "For stubborn stains, rub apple cider vinegar directly on your teeth then rinse with water," his website claims. But it also adds the caveat "be careful not to do this too often, as it can break down tooth enamel."

Given its acidity, that last part is about all dentists will agree with, because the acid in vinegar erodes the protective enamel on teeth, leaving them more vulnerable to cavities. As science writer Dylan McCarthy, lead editor of website The Dental Geek writes, "the most popular brand of unfiltered apple cider vinegar clocks in with a pH level of 2.85. ... This puts apple cider vinegar above soda, about on par with lemon juice, and just under stomach acid and battery acid in terms of acidity." By contrast, a pH level of seven is neutral.

Even alternative medicine guru Joseph Mercola, one of the most notorious pseudoscientific sources on the internet, admits that using apple cider vinegar on your teeth isn't a good idea, writing, "pure, straight apple cider vinegar could damage your tooth enamel or the tissues of your mouth."

Claim: Apple cider vinegar can naturally cure cancer by making the body less acidic.

This claim is where we leave the realm of popular natural products and enter that of dangerous psuedoscience. Websites like "The Truth About Cancer" and others promote apple cider vinegar as a miracle cure-all when mixed with baking soda, claiming that it changes the pH of the body to make it less acidic, thereby making it inhospitable to cancer cells.

However, this is complete nonsense, based on extremely dubious science and a fundamental misunderstanding of how chemistry works. While there's no compelling evidence of acidity and cancer being linked, the theory has launched countless quack cures. Under no circumstances should one use apple cider vinegar as a substitute for science-based medical treatment.

While apple cider vinegar is likely a staple in the pantry for many, it's important to keep in mind that if something sounds too good to be true - it probably is too good to be true.