Apple cider vinegar is said to have a range of health benefits. Where does the evidence currently stand? Photo / Getty Images
Several studies have shown apple cider vinegar can lower blood sugar levels and slightly improve cholesterol, but there are caveats.
Apple cider vinegar has long had a reputation as an elixir that can do wonders for your health. To some extent, its reputation is deserved.
Many studies have shown that apple cider vinegar can lower blood sugar levels and slightly improve cholesterol levels. A few studies have shown that it might help you lose weight. And apple cider vinegar typically contains health-promoting bacteria, known as probiotics, that according to studies can nourish your gut microbiome.
But there are caveats. Most of the studies on apple cider vinegar have been fairly small and, in some cases, poorly designed. So the evidence is not particularly strong or definitive, experts say. Apple cider vinegar also has the potential to cause side effects in people who are taking medication to treat type 2 diabetes, high blood pressure and other chronic conditions.
And experts advise against drinking it pure. Instead, it’s better to incorporate apple cider vinegar into your meals or to mix it into a glass of water.
For people who are curious about it, taking a few teaspoons a day is fairly low risk and may lead to slight health improvements, so it could be worth trying, said Beth Czerwony, a registered dietitian with the Cleveland Clinic’s Center for Human Nutrition.
“There are some studies that suggest it could be beneficial,” she said. “It may help a little in some cases, but it’s not a guarantee, and it’s certainly not going to be a cure for anything like diabetes or obesity.”
Vinegar’s reputation as a natural remedy began more than 2000 years ago. Hippocrates, the ancient Greek physician and often called the father of medicine, used vinegar to clean wounds and prescribed a mixture of honey and vinegar to treat coughs. In the late 18th century, American physicians turned to vinegar to relieve stomach aches, croup, oedema and other conditions.
Vinegar comes in many forms. It’s usually made by fermenting corn, wheat, potatoes, grapes and a variety of other plants through a two-step process. During the first step, yeast feed on the sugars and starches in the plants, turning them into alcohol. Then bacteria convert that alcohol into acetic acid, which gives us vinegar. Most commercial vinegar is then pasteurised, which kills its microorganisms.
Apple cider vinegar is often unpasteurised, meaning it retains all the friendly microbes or probiotics that carried out the fermentation process, and it contains antioxidants and minerals. You can usually tell whether a bottle of apple cider vinegar contains probiotics by reading the label. It should say that it is “unpasteurised” or that it contains the “mother,” which is the combination of friendly yeast and bacteria.
Much of the research on apple cider vinegar has looked at its impact on blood sugar and cholesterol levels.
In one clinical trial published last year, researchers recruited 80 adults with type 2 diabetes, split them into two groups, and then followed them for eight weeks. Both groups were told to eat a healthy diet with plenty of fruits, vegetables and whole grains while limiting junk foods high in salt, sugar and fat. One group was also instructed to consume the equivalent of two tablespoons of apple cider vinegar daily, ideally with lunch or immediately after it. They were told that they could dilute the vinegar in water.
After eight weeks, the researchers found that the people in the apple cider vinegar group had significantly greater reductions in their blood sugar levels. They had larger improvements in their cholesterol and triglyceride levels, and greater reductions in their body weight and waist circumference.
In another study published in 2021, researchers conducted a systematic review and meta-analysis of nine clinical trials on apple cider vinegar. The trials lasted anywhere from eight weeks to three months. In most cases, the participants were instructed to take one to two tablespoons of apple cider vinegar daily. The researchers found overall that consuming at least one tablespoon of apple cider vinegar every day for eight weeks or longer led to reductions in blood sugar, triglycerides and total cholesterol levels, but that this effect was only significant in people who had type 2 diabetes.
The researchers speculated that apple cider vinegar improves metabolic health in part by slowing the speed at which food travels from the stomach to the small intestine, which causes a slower release of glucose and other nutrients into your bloodstream. It may also boost your body’s ability to metabolise fat and glucose.
But there is some reason to be cautious. In many of the studies, apple cider vinegar was paired with a low-calorie diet, which could have explained the improvements in weight and metabolic health, said Czerwony at the Cleveland Clinic. “I think in some studies it was really unclear if it was the apple cider vinegar or the calorie deficit that caused weight loss.”
One study found that people who consumed apple cider vinegar lost weight because their appetites shrank and they ended up eating less food. Another small study found that consuming vinegar before a meal caused people to eat less food because the vinegar made them feel nauseous.
In 2022, a group of researchers published a review of seven studies that looked at the effects of vinegar on appetite and food intake. They found that consuming vinegar alongside a meal could suppress appetite in the short term, potentially reducing the amount a person eats that day. But ultimately consuming vinegar did not have any significant impact on appetite over the course of days or weeks. They concluded that more research was needed to determine whether regularly consuming vinegar could reduce appetite and cause weight loss over the long term.
The best way to consume apple cider vinegar is to add it to your foods, said Kelly Springer, a registered dietitian and the owner of Kelly’s Choice, a nutrition company based in Skaneateles, New York.
She recommends using it in marinades and salad dressings, for example by mixing apple cider vinegar with olive oil and a little garlic powder. This is a great combination because apple cider vinegar provides probiotics while garlic is a prebiotic that feeds the beneficial bacteria in your gut, Springer said.
Another option is to mix a little apple cider vinegar into a glass of water or a cup of tea. But start with a small amount, such as a teaspoon or two. And never drink it by itself because vinegar can cause tooth erosion, stomach upset or discolouration of your teeth. “You really don’t want to take vinegar alone because it’s very acidic,” Springer said.
If you have a chronic condition or take medication, then talk to your doctor before using apple cider vinegar for health reasons. Combining apple cider vinegar with a diabetes medication could cause your blood sugar levels to drop too low. Consuming a lot of vinegar could also cause your potassium levels to fall, which could be dangerous when combined with diuretics and other drugs that lower potassium. It can also worsen acid reflux and irritate the lining of your throat.
“If you are experiencing negative side effects, don’t feel like the pros are going to outweigh the cons,” Czerwony said. “Don’t keep using it because then you’re just putting yourself in a bad situation and making yourself uncomfortable or eroding the enamel on your teeth.”
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