Apple cider vinegar (ACV), a centuries-old liquid, has long been hailed as a natural treatment for curing all types of health conditions. But are its healing properties fact or folklore?
The fermented beverage made from apples undergoes a two-step process wherein the juice's natural sugars are converted first into alcohol and then into acetic acid. Unfiltered ACV — labeled as "with the mother" — contains dark, murky strands of enzymes, proteins, B vitamins, probiotics and plant-based antioxidants called polyphenols. According to the University of Chicago Medicine, it's these nutrients that are responsible for ACV's reputed health benefits.
"Vinegar has been linked to everything from treating illnesses to cleaning furniture to detoxing," Keri Glassman, RD, founder of Nutritious Life, tells LIVESTRONG.com. "ACV, in particular, is often touted as a health cure-all with numerous benefits. But most of these claims are not backed up by research."
In fact, most of the studies on ACV's potential health benefits have been small and many of the experiments have been performed on animals. Here's the most current ACV data involving humans.
Apple Cider Vinegar and Weight Loss
There's limited evidence to support the so-called "apple cider vinegar diet." A small April 2018 study published in the Journal of Functional Foods separated 39 adults into two groups. The first group was instructed to take one tablespoon of ACV during lunch and dinner while also reducing their total daily food intake by 250 calories. The second group — the control group — only reduced their total calories and didn't take any ACV.
After 12 weeks, the researchers discovered that the ACV drinkers had "significantly reduced" their body weight by an average of 8.8 pounds. The other group lost weight too, but their average weight loss was just 5 pounds. The study authors also reported that the participants who took ACV showed a decrease in appetite, a decrease in overall cholesterol levels and an increase in "good" cholesterol (HDL).
There is other research that supports a possible link between vinegar and suppressed appetite, and therefore weight control. According to a scientific review published in the August 2016 issue of Molecular Nutrition & Food Research, vinegar was shown to lead to a series of mechanisms that resulted in increased satiety and lower food intake, but only among people who were not living with type 2 diabetes. (Note: All vinegars seem to have this effect, not just ACV.)
The bottom line: "Is apple cider vinegar a weight-loss miracle? No way," Erin Palinski-Wade, RD, CDE and author of the 2-Day Diabetes Diet, tells LIVESTRONG.com. "Could it help curb cravings and keep you fuller longer? Maybe so."
Read more: How to Lose Weight Fast — the Healthy Way
Apple Cider Vinegar and Diabetes
A few scientists have examined the possible effects that ACV may have on blood glucose levels in people living with diabetes. "A study found that a tablespoon of ACV before meals lowered blood glucose levels in adults at risk for type 2 diabetes," says Glassman. It's important to note that this 12-week pilot study in the October 2013 issue of the Journal of Functional Foods was comprised of just 14 adults.
Palinski-Wade cites another study, which focuses on vinegar's effects on postprandial glucose and insulin levels. The findings suggest that ACV and other vinegars may help people with diabetes improve their glycemic control, per the meta-analysis published in the May 2017 issue of Diabetes Research and Clinical Practice. And a small study published in May 2015 in the Journal of Diabetes Research found similar results.
"You don't have to have diabetes or prediabetes to reap the benefits that come with avoiding blood sugar spikes," says Palinski-Wade. "ACV may be beneficial for people with diabetes as well as those wanting to promote health."
Glassman concurs: "The studies suggest that vinegar plays a role in the breaking down of carbohydrates, particularly starches," she states. "Over time, that could also contribute to an effective weight loss program in certain people. But it's a far cry from, 'Drink this, drop pounds.'"
Apple Cider Vinegar and Cholesterol
The April 2018 Journal of Functional Foods study found a possible association between ACV and healthier cholesterol levels. Similarly, medical researchers from Iran analyzed ACV's effect on people who've been diagnosed with hyperlipidemia, otherwise known as high cholesterol.
Read more: The 9 Best Cholesterol-Lowering Foods
At the conclusion of the eight-week experiment, the participants showed a "significant reduction" in multiple blood lipid levels, including total cholesterol, triglycerides and LDL ("bad") cholesterol. However, while the volunteers' test results also showed an increase in HDL cholesterol levels, the authors stated that the improvement was not statistically significant, per the 2012 study in Life Science Journal.
Keep in mind that the latter study was also very small, involving just 19 people. Also, the researchers referred to their investigation as a "quasi-experiment," meaning that the control and treatment groups differed in terms of treatments administered, as well as in other ways, per Research Connections.
The Bottom Line
Due to its high acidity, consuming too much ACV can have negative side effects, including upset stomach, tooth decay and tissue damage to the esophagus. The University of Washington recommends taking in no more than two tablespoons of ACV per day.
"Unfortunately, vinegar is not a miracle liquid," notes Glassman. However, she concludes that it is a healthy low-calorie condiment, and she recommends sprinkling a serving of ACV onto salad and vegetable dishes.
"Adding vinegar to your daily routine is certainly not going to hurt, and if it gets you to eat more veggies, even better," she says. "Another bonus: You can use it instead of salt to add flavor [to food], which will help keep the belly bloat at bay."
- UChicagoMedicine: "Debunking The Health Benefits of Apple Cider Vinegar"
- Journal of Functional Foods: "Beneficial Effects of ACV on Weight Management"
- Molecular Nutrition & Food Research: "Vinegar As a Functional Ingredient to Improve Postprandial Glycemic Control"
- Journal of Functional Foods: "Vinegar Ingestion at Mealtime Reduced Fasting Blood Glucose Concentrations in Healthy Adults at Risk for Type 2 Diabetes"
- Diabetes Research Clinc Practice: "Vinegar Consumption Can Attenuate Postprandial Glucose and Insulin Responses"
- Journal of Diabetes Research: "Vinegar Consumption Increases Insulin-Stimulated Glucose Uptake"
- Life Science Journal: "Influence on ACV on Blood Lipids"
- Research Connections: "Experiments and Quasi-Experiments"
- University of Washington: "Beyond the Hype: ACV as an Alternative Therapy"