The popular new Netflix show Apple Cider Vinegar isn’t about the titular vinegar – it’s about the influencer Belle Gibson claiming she cured brain cancer by adopting a whole food diet.

Yet apple cider vinegar is a fitting symbol for society’s obsession with miracle health cures.

For millennia, healers, herbalists and wellness enthusiasts of all stripes have sworn by apple cider vinegar’s supposed benefits. Search “apple cider vinegar + [insert ailment]” and you’ll find someone claiming it helps with everything from sunburn to kidney stones to even neurodegenerative disease. Infused with garlic, onions and hot peppers, it becomes fire cider, a folk remedy said to boost immunity and take the edge off colds. A few tablespoons mixed into water? A digestive aid. Dabbed on to bruises? A home remedy.

Many of the health claims people make about apple cider vinegar are based on anecdote and tradition. But some of its applications draw on clinical research and are considered worthwhile by doctors and dietitians. So what does the science really say about apple cider vinegar’s health effects and practical uses?

Is apple cider vinegar safe?

Apple cider vinegar is neither magic nor snake oil. Rather, it’s a healthy pantry staple most people can incorporate into their diets safely.

Unpasteurized apple cider vinegar with “the mother”, a brownish murk of friendly microbes, is rich in polyphenols, a kind of antioxidant, and probiotics, which contribute to beneficial gut bacteria.

The typical serving recommendation is a tablespoon of vinegar diluted in 8oz of water. Effects will depend on the individual. For those with acid reflux, ulcers or gastritis, vinegar’s high levels of acetic acid may feel too harsh. As with any supplement, it’s a good idea to talk to your doctor before incorporating apple cider vinegar into your routine, particularly for those on diabetes medications or drugs that affect potassium levels, or those with kidney disease, as their kidneys may struggle to process high doses of acid. It’s also worth noting that acid can be hard on tooth enamel.

Apple cider vinegar is anti-microbial against pathogens, which means it can do double-duty as a salad dressing ingredient and a sanitizer for any sneaky E coli hanging out on your lettuce. Adding it to a bowl of water when washing produce can help kill off microbes, and keep your veg fresh for longer in the fridge.

More research is needed before we know whether vinegar can be officially recommended for fighting pathogens inside the body, but the research so far paints a compelling picture of an accessible way to inhibit bacterial growth in vitro.

Can apple cider vinegar help with blood glucose levels and diabetes?

Much of the research about drinking apple cider vinegar to control blood sugar has comprised only small, short, interventional trials. One 2023 study, with a cohort of 80 adults with type 2 diabetes, found that those who consumed two tablespoons of apple cider vinegar a day had significantly greater reductions in their blood sugar levels, as well as larger improvements in their cholesterol and triglyceride levels, and greater weight loss than the control. A 2021 meta-analysis found fairly consistent reductions in blood sugar spikes and triglycerides in patients with type 2 diabetes.

Several studies have found apple cider vinegar may support metabolic health by slowing digestion, leading to a steadier release of glucose into the bloodstream – potentially useful when consuming meals high in simple carbohydrates. Additional research supports that apple cider vinegar may also enhance the body’s ability to process fat and glucose more efficiently.

However, Dr Dan Bessesen, a professor of endocrinology, metabolism and diabetes at the University of Colorado School of Medicine, takes these studies with a grain of salt.

“When you’re looking at something like glucose or cholesterol or weight, these are chronic conditions where you would want to see some meaningful long-term benefits,” such as the prevention of heart problems or type 2 diabetes. “But there really are no long-term studies,” he says.

Perhaps apple cider vinegar “was the GLP-1 agonist of 1,000 years ago”, says Bessesen, but compared to the glucose-lowering drugs available today, its effects are significantly less potent and reliable, he says: a complementary tonic perhaps, but not a replacement for diabetes medication.

Can apple cider vinegar help with weight loss and digestive issues?

Among the wellness set, the idea is popular that apple cider vinegar can help otherwise healthy individuals lose weight, improve digestion and combat bloat.

Sammy Peterson, an Arizona-based registered dietitian, says that because apple cider vinegar may slow digestion and supports a healthy gut microbiome, it makes sense that drinking it may help with bloat or stomach upset, though the evidence for it is mostly anecdotal.

When it comes to weight loss, studies are small, and in some cases complicated by factors such as participants also following lower-calorie diets or not reporting their diets while taking apple cider vinegar. “Research suggests that apple cider vinegar may help support what’s called satiety, or being more full from our meals, which is our ultimate goal when we’re looking at something like weight loss,” notes Peterson.

One 2005 study found that participants who drank apple cider vinegar before a meal consumed up to 275 fewer calories throughout the rest of the day. But it’s not clear why – the vinegar could have made them feel less hungry or it could have made them feel nauseous.

Really, if you want to lose weight, Peterson says, balanced nutrition, daily movement, stress reduction and adequate sleep are much more important than any supplement. And as far as adding it to your diet to lose weight, Bessesen thinks the “evidence for apple cider vinegar is pretty weak”.

Is topical apple cider vinegar good for hair and scalp care?

Studies on apple cider vinegar and eczema and atopic dermatitis do not demonstrate that vinegar changes the skin’s microbiome. But Dr Jeff Donovan, a British Columbia-based board-certified dermatologist specializing in conditions affecting the hair and scalp, has seen promising outcomes with patients using apple cider vinegar to treat certain scalp conditions.

“I am a real proponent of apple cider vinegar,” he says.

For the last decade he has been recommending topical apple cider vinegar application to patients with dandruff, or scaling and itching symptoms associated with seborrheic dermatitis or psoriasis. “It acts as a wonderful clarifying agent to lift scale,” says Donovan, who recommends diluting the vinegar with four parts water, applying it to the scalp with a spray bottle, and waiting 10 minutes or so before washing it out. Diluting the vinegar reduces the chance of sustaining a chemical burn, and the mixture can also be safely used as an occasional clarifying hair rinse. It might, however, dry out tissue if used too frequently.

Apple cider vinegar demonstrates activity against bacteria, fungi and yeast “in a test tube”, says Donovan. But “the limited studies that have been done have suggested it doesn’t actually do that in human beings”, he says. We don’t know exactly how apple cider vinegar is benefitting people with scalp conditions – only that it’s cheap and safe. Donovan says some patients who have used it as directed have had significant improvement in scaly skin and itching, and did not have to then use strong medications like corticosteroids. “The only complaint I’ve ever had from a patient is that it didn’t do anything for them,” says Donovan.