Apple cider vinegar is a popular choice for adding a punchy flavor to food, but many also tout it as a “miracle food” to treat many ailments. How accurate are these claims?

Apple cider vinegar not only adds a delicious tang to dishes prepared worldwide but has also gained popularity recently as a natural home remedy for various health issues. Apple cider vinegar has been touted as a “miracle food” throughout the centuries for its many declared health benefits.

Making apple cider vinegar involves crushing and exposing apples to yeast, which turns their fermented sugars into alcohol. Then, bacteria are added that further ferments the alcohol, turning it into the main active compound in vinegar called acetic acid. Acetic acid gives vinegar its unmistakable sour flavor and smell and is believed to contribute to its many health-boosting properties.

But is apple cider vinegar safe for everyone to consume, and what are the health claims associated with it? Let’s explore the evidence to see whether these claims genuinely hold up.

Can it help you manage your blood sugar?

When consumed with a meal, apple cider vinegar can lead to an improvement in blood glucose and greater insulin sensitivity, especially in people with type 2 diabetes. This is due to vinegar’s acetic acid and its ability to inhibit the enzyme responsible for breaking down carbohydrates and improve the process by which cells take up glucose from the bloodstream. And like fiber, protein, and fat, because acetic acid in vinegar slows how quickly carbohydrates break down into glucose during digestion, it delays the time that food exits the stomach and hinders the absorption of sugar.

One study saw vinegar’s blood sugar-lowering effect firsthand, assessing whether consuming vinegar at night time reduces fasting glucose concentrations in 110 adult subjects with type 2 diabetes. In the study, an experimental group of 55 subjects consumed 1 tablespoon of apple cider vinegar mixed into 200 ml (approx. 6.8 oz) of water during a night time meal and a placebo group of 55 subjects consumed 1 tablespoon of an artificial apple cider vinegar-flavored liquid mixed into 200 ml of water during a night time meal. Both groups consumed their drinks each night for three months. After the trial period, the researchers found that the placebo group that ingested the artificial apple cider vinegar drink each night did not see a significant change in their fasting glucose concentration, whereas the experimental group that ingested apple cider vinegar each night lowered their fasting glucose concentration from an average 170 mg/dL to 157 mg/dL.

To reap the benefit from vinegar’s blood glucose-lowering effect, some experts recommend drizzling two tablespoons of vinegar onto a salad or mixing it into a tall glass of water before dining. Any type of vinegar will do, but apple cider vinegar is a popular choice.

Can it help you lose weight?

Providing only 3 calories per tablespoon, apple cider vinegar can be a tasty, low-calorie addition to your diet. And some suggest that drinking a small amount before eating can burn fat and help to keep appetite in check. But can it help you to lose weight, as many of its proponents claim?

One Japanese study appears to suggest so. Researchers investigated the effects of a regular intake of apple cider vinegar on the body weight of 175 adults with obesity over 12 weeks. At the start of the study, the subjects initially shared similar body mass index, body weight, and waist circumference and were grouped into three categories: Group 1 drank a 500 ml beverage containing 15 ml (1 tablespoon) of vinegar each day, Group 2 drank a 500 ml beverage containing 30 ml (2 tablespoons) of vinegar each day, and Group 3 drank a 500 ml beverage each day that did not have any vinegar. After 4 weeks of daily apple cider vinegar consumption, both the low and high-dose groups experienced a reduction in body weight by 0.89 lb and 1.1 lb, respectively, whereas the group that drank no vinegar gained 0.22 lb. By week 12, the low-dose group saw a body weight loss of 2.6 lb, whereas the high-dose group lost 4.2 lb. The group that did not drink vinegar gained 0.88 lb.

It is important to note, though, that like any singular food or drink, apple cider vinegar may not be the direct cause of weight loss all on its own. The key to long-term weight loss most often requires adopting a healthy, sustainable lifestyle. But vinegar can contribute to weight loss by reducing the spike in blood sugar and insulin levels you would usually see after eating - factors that may contribute to weight gain.

Can it kill harmful bacteria?

Due to its 5% to 6% acetic acid component, apple cider vinegar has long been recognized for its antibacterial properties. Hippocrates, the “father of medicine,” himself used a potent mixture of apple cider vinegar with honey to treat his patients’ skin wounds and infections in 400 B.C.

Many of today’s scientific experts appear to agree with this approach. Recent researchers studied the effects of different concentrations of apple cider on the growth of S. aureus, C. albicans, and E-coli, three types of bacteria known to cause inflammation and infection in the body. They saw that when they applied either undiluted or diluted apple cider vinegar to each bacteria, their growth was inhibited. Specifically, undiluted 5% acidity restricted growth for C. albicans, diluted 2.5% acidity restricted S. aureus growth, and 0.1% acidity was all it took to inhibit the growth of E-coli.

Acetic acid may be effective at killing bacteria because of its ability to cross into a bacteria’s cell, disrupting its membrane and leading to an increase in the production of antimicrobial peptides, small proteins that have the ability to kill or inhibit the growth of a wide range of bacteria, fungi, viruses, and other harmful organisms.

Can it protect your brain health?

Dementia, a condition associated with aging characterized by memory loss, language challenges, and impairment in intellectual abilities, afflicts over 5 million people worldwide. Alzheimer’s disease is the most common type of dementia, and although scientists are still working to uncover the exact cause, it is believed that one of the causes is the formation of amyloid plaques, which occurs when abnormal protein fragments accumulate in the brain, contributing to the death of brain cells.

Apples are naturally high in antioxidants, substances that can help protect cells from damage caused by molecules called free radicals. Polyphenols are a type of antioxidant that are found in plants, vegetables, and fruits. Apple cider vinegar is especially high in the polyphenols gallic acid, catechin, and caffeic acid.  It is suggested that these compounds may work to protect against memory decline and Alzheimer’s disease by easing inflammation and reducing oxidative stress. Oxidative stress is an imbalance between the production of free radicals and the body’s ability to neutralize them, and it is thought that oxidative stress may play a role in the development of Alzheimer’s disease. Because antioxidants can help reduce oxidative stress, it is claimed that they may be able to help prevent or delay its onset.

There have been several studies that have looked at the potential role of antioxidants in preventing Alzheimer's disease, but the results have been mixed. More research is needed to fully understand the relationship between antioxidants and Alzheimer's disease.

What you should know about apple cider vinegar

While using apple cider vinegar in small amounts in food and dressings is generally considered safe, there are some potential risks and side effects to watch out for.

Apple cider vinegar is highly acidic and can wear down tooth enamel, the protective hard outer surface of teeth, leaving teeth prone to cavities and sensitivity. Applying apple cider vinegar to the skin for extended periods may also cause burns and irritation, especially in people with sensitive skin. Apple cider vinegar can also burn and irritate the eyes, so use caution when applying it to the face, hair, and scalp. To avoid irritation of the throat and minimize tooth enamel erosion while drinking, dilute apple cider vinegar with water by mixing 1 teaspoon with at least 8 ounces of water. As always, speak with your healthcare provider before using apple cider vinegar to treat a medical condition or if you plan to consume it in larger quantities.

The bottom line

There is some promising evidence that consuming apple cider vinegar may have potential health benefits by helping to manage blood sugar, aid in weight loss, kill harmful bacteria, and protect against cognitive decline. But it is important to note that many of these health claims are still being researched and have not yet been fully proven. If you add apple cider vinegar to your diet, do so safely. Consuming apple cider vinegar undiluted or in large amounts can lead to harsh side effects, so it is recommended to consume it in small quantities or dilute it with water before drinking. As with any natural remedy, it is always best to consult a healthcare professional before adding apple cider vinegar to your routine.