Apple Cider Vinegar: What the Research Says and How to Use It Safely

2026-10-20T09:42:05.151166Z

In short: Apple cider vinegar is a useful kitchen ingredient, and the strongest research support is for a small effect on blood sugar, especially in people with type 2 diabetes, with a slight improvement in total cholesterol in some studies. Claims about burning fat, detoxing the body or curing disease aren't proven. Never drink it undiluted; dilute it in water or use it in salads and marinades, and talk to your doctor if you take diabetes medicines or diuretics.

Apple cider vinegar is one of the most hyped products on social media: a glass of warm water with a spoon of vinegar on an empty stomach, with promises of weight loss, better digestion and clearer skin. The reality is simpler. Apple cider vinegar comes from fermenting apple juice twice: first the sugar turns into alcohol, then the alcohol turns into acetic acid, the main component behind its sour taste and most of its studied effects. According to the American Heart Association, it's mostly water, nearly 94%, with very small amounts of minerals.

What does the research say?

Blood sugar: the strongest evidence

This is the best-supported claim, but it's smaller than people think. A 2021 meta-analysis in BMC Complementary Medicine and Therapies pooled nine randomized clinical trials and found that apple cider vinegar lowered fasting blood glucose by about 8 mg/dL on average and HbA1c by about half a point, with a clearer effect in people with type 2 diabetes and in studies lasting more than eight weeks. But the researchers noted large differences between studies, most of which were small and short.

How does it work? Acetic acid is thought to slow stomach emptying and reduce how quickly carbohydrates are absorbed after a meal. That explains why the effect shows up more when it's taken with a starchy meal.

Cholesterol

The same meta-analysis found a slight drop in total cholesterol (about 6 mg/dL) and triglycerides in some groups, and no clear effect on LDL or HDL cholesterol. The effect exists in some cases but is limited.

Weight

Some small, short studies showed slight reductions in weight or appetite, but they aren't enough to say apple cider vinegar "burns fat". The dietitian interviewed by the American Heart Association summed it up: it won't replace a healthy diet and regular physical activity.

Digestion and "the mother"

Unfiltered apple cider vinegar contains "the mother", a mix of bacteria and proteins formed during fermentation. Many brands market it as a probiotic source, but there's no strong evidence that the amount in a spoon of vinegar meaningfully changes gut health. Choosing unfiltered vinegar is more a matter of taste and preference than proven benefit.

Claim	Strength of evidence	Bottom line
Lowers blood sugar	Moderate	Small effect, clearer in type 2 diabetes
Improves cholesterol	Limited	Slight drop in total cholesterol and triglycerides
Weight loss	Weak	Small, short studies; no substitute for healthy eating
Better digestion	Very weak	Not enough evidence
Detoxing the body	Not proven	Your liver and kidneys do that job

How to use it safely

Apple cider vinegar is very acidic, similar to or more acidic than lemon juice. That's why medical sources warn against drinking it undiluted: it can erode tooth enamel and irritate the oesophagus and throat, and some people get heartburn or an upset stomach.

Always dilute it: one to two tablespoons (15 to 30 ml) in a large glass of water, the amounts most often used in studies.
Better with food: add it to salads, dressings or homemade pickles. You get the flavor and the vegetables together.
Protect your teeth: drink it diluted through a straw, rinse your mouth with water afterwards, and don't brush straight after, because the acid temporarily softens enamel.
Start small: and watch how your stomach reacts, especially if you have reflux.

Tip: The easiest daily habit: a salad dressing of one spoon of apple cider vinegar, two spoons of extra virgin olive oil, a pinch of salt and pepper and a little mustard. You get the tang without bothering your teeth or stomach.

Apple cider vinegar pills and gummies: worth it?

Apple cider vinegar supplements have spread as capsules and gummies. The problem is that most studies used liquid vinegar, not these forms, and the amount of acetic acid varies widely between products. Gummies also often contain added sugar, which works against the goal if you're using them for blood sugar. The Academy of Nutrition and Dietetics also notes reports of apple cider vinegar tablets getting stuck in the throat. If you want apple cider vinegar, a regular bottle is much cheaper and closer to what's been studied.

How to choose a bottle

Acidity: most food-grade apple cider vinegar is about 5% acidity, usually printed on the label.
Filtered or unfiltered: filtered is clear and milder; unfiltered is cloudy and contains "the mother". Both are fine for cooking.
Organic or regular: organic means the apples were grown to organic standards; it doesn't mean proven extra health benefits for the vinegar itself.
Ingredients: some versions add honey, juices or flavors. That changes the taste and may add sugar, so read the label.

Ideas for using apple cider vinegar in the kitchen

The best way to benefit from apple cider vinegar is to treat it as a food ingredient, not a medicine. That way you get its flavor and sometimes swap out less helpful ingredients like ready-made sauces high in sugar and salt:

Everyday salad dressing: instead of bottled dressings; make a week's worth in a glass jar in the fridge.
Chicken and meat marinades: with garlic, spices and olive oil, it adds gentle acidity and helps tenderise meat.
Homemade pickles: cucumber, carrot and onion in vinegar, water and salt, with no added colors or preservatives.
With legumes: a splash over lentil or chickpea salad gives a fresh lift.
In soups: a little at the end of cooking balances the flavor and reduces the need for extra salt.

Who should be careful?

Note: If you take diabetes medicines (especially insulin), diuretics or heart medicines such as digoxin, talk to your doctor before taking apple cider vinegar regularly, because it may deepen low blood sugar, and large amounts over long periods may be linked to low potassium. The same applies if you have reflux, a stomach ulcer or delayed stomach emptying, or enamel erosion. Apple cider vinegar doesn't treat diabetes and isn't a substitute for medication.

Frequently asked questions

Should I drink apple cider vinegar on an empty stomach?

There's no evidence that an empty stomach is better. The studied effect on blood sugar usually appears when it's taken with or just before a meal, and on an empty stomach it can cause heartburn for some people.