It adds flavor to your food, but does apple cider vinegar deserve its reputation as a natural remedy with a whole host of health benefits?
It certainly has antimicrobial properties, and it can contain probiotic bacteria that may be good for your gut microbes.
At ZOE, we run the world’s largest ongoing scientific study of nutrition — with over 20,000 participants so far — and we understand how important your gut microbiome is for good health. If you’d like to learn about the bugs that live in your gut, you can start by taking our free quiz.
Aside from looking at its potential probiotic benefits, we will also investigate claims that apple cider vinegar can help with blood sugar control, weight loss, cholesterol levels, blood pressure, acne, and acid reflux.
Read on as we assess the evidence and look at some possible risks and side effects.
What is apple cider vinegar?
Apple cider vinegar is made by crushing or chopping apples, then letting yeast ferment the juice into alcohol.
Adding a type of bacteria called acetobacter starts the second stage of fermentation, which turns the alcohol into acetic acid and gives vinegar its distinctive taste.
Like other kinds of vinegar, you can use apple cider vinegar in salad dressings, sauces, and baking. People also use it for pickling and preserving food. Vinegar also has a long history of use in traditional medicine.
Because of its supposed health benefits, some people today drink apple cider vinegar in “shots” diluted with water or fruit juice.
How might apple cider vinegar support good health?
It’s easy to see why people might expect apple cider vinegar to be good for your health.
It’s a rich source of antioxidants called polyphenols, which help support your “good” gut bacteria.
The acetic acid it contains is also antibacterial and antifungal, which explains why people have used vinegar to clean wounds as far back as the Ancient Greeks.
Some people believe that apple cider vinegar’s potential health benefits come from what’s known as “the mother.”
The mother is the probiotic blend of bacteria and yeasts, which you can see as wispy strands in unfiltered apple cider vinegar.
Probiotic foods contain “good” bacteria that can help to support your gut microbiome — the trillions of bugs that live in your gut. These microbes are essential to good health, and everyone’s gut microbiome is unique.
The ZOE at-home test can tell you what bacteria live in your gut and provide personalized nutrition advice to boost your gut health. If you’d like to learn more about your unique gut microbiome, take our free quiz today.
What are the health claims?
There’s a wide range of health claims around apple cider vinegar — but does the science back them up?
From blood sugar control to acne treatment, we assess the evidence.
1. Blood sugar control
If you have type 2 diabetes or insulin resistance, your body finds it more difficult to control blood sugar levels. However, anyone can experience spikes or crashes in blood sugar following a meal. Over time, this can increase the risk of chronic disease.
A recent meta-analysis combined the results of six trials with a total of 317 participants. The authors found that consuming 1–2 tablespoons of vinegar decreased fasting blood sugar and HbA1c, a marker of long-term blood sugar.
The authors also found that apple cider vinegar was more effective than other kinds of vinegar at controlling blood sugar. These results suggest that apple cider vinegar could be a helpful addition to your diet, together with physical activity and medication, to control blood sugar levels.
At ZOE, our research has shown that everyone’s blood sugar levels respond differently to food. Even identical twins can have different responses to the same food.
If you’d like to know more, you can read about our at-home test.
2. Weight loss
Could apple cider vinegar help you to improve your health by losing weight? So far, the jury is out because the results of studies are conflicting.
In one study, scientists split 39 participants with overweight or obesity into two groups. Both groups followed a calorie-restricted diet, and one group also consumed around 2 tbsp (30 ml) of apple cider vinegar each day.
After 12 weeks, the researchers compared the two groups. Those taking apple cider vinegar lost around 1.5 kg (3.3 lbs) more weight on average than those not taking apple cider vinegar. The apple cider vinegar group also said they had a lower appetite.
Another study involving 175 participants with overweight and no dietary restrictions found a small reduction in body weight (on average 1–2 kg, or 2.2–4.4 lbs), as well as reductions in abdominal fat and waist circumference.
But results so far are inconsistent and are based on short-term studies. So, it’s unclear how apple cider vinegar would work in the long run.
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3. Antimicrobial properties
At a time when the overuse of antibiotics is making them less and less effective, scientists are keen to identify new ways of fighting infections.
Early laboratory studies have found that apple cider vinegar, either neat or diluted with water, can restrict the growth of these common microbes:
Escherichia coli: A bacterium that can cause gastroenteritis, urinary infections, and neonatal meningitis.
Staphylococcus aureus: A bacterium that can cause skin infections, food poisoning, and bone, joint, and blood infections.
Candida albicans: A yeast that can cause infections ranging from vaginal thrush to potentially life-threatening illnesses.
While the use of apple cider vinegar in medical settings is a long way off, its antimicrobial properties could have more practical day-to-day benefits.
Studies have found that soaking carrots, arugula, and spring onions infected with salmonella in a mixture of equal parts vinegar and lemon juice for 30–60 minutes reduced the bacteria to undetectable levels.
4. Blood fat levels
When you eat, blood fat levels rise. This is normal, but if levels remain high, it can affect your health.
Recently, researchers pooled nine studies to examine the overall effects of apple cider vinegar on cholesterol.
They found that apple cider vinegar improved total cholesterol levels, especially for people with type 2 diabetes. The authors suggested that 15 milliliters (1 tbsp) of apple cider vinegar each day might be the ideal amount, with the largest effects after 8 weeks.
However, due to the limitations of existing research, the authors write that “the findings should be interpreted with caution.”
Overall, it does look like apple cider vinegar might help improve cholesterol levels as an add-on to other treatments, but it’s clear that more research is needed.
If you would like to learn how your blood fat levels respond to food, start by taking ZOE’s free quiz.
5. Blood pressure
Although some people believe that apple cider vinegar can lower blood pressure, there’s currently not much evidence from human studies to support the idea.
Research in rats has shown an association between long-term consumption of acetic acid and reduced blood pressure.
However, the limited number of human studies have not found a similar link.
For instance, in one study, 70 people with type 2 diabetes took either a placebo or 20 ml of apple cider vinegar each day.
After 8 weeks, researchers found no noticeable differences in participants’ blood pressure or levels of a related amino acid called homocysteine.
6. Acid reflux
Acid reflux, or gastroesophageal reflux, is when some of the content from your stomach rises back up into your esophagus. This causes pain, which is often called heartburn.
Some people claim that taking apple cider vinegar helps reduce their symptoms of acid reflux, perhaps by improving their digestion.
However, there’s no evidence to support this as there has been very little research into apple cider vinegar for acid reflux.
One of the factors contributing to acne is the bacterium Propionibacterium acnes. And because apple cider vinegar has antimicrobial properties, some people have wondered if it might help treat acne.
However, there’s currently no research that backs this up.
In some cases, using neat apple cider vinegar on skin has caused chemical burns, so this is not something to try at home.
Risks and side effects
The acid in apple cider vinegar has the potential to cause issues if you don’t dilute it properly or use too much of it. The recommended benefits are seen with consuming 1–2 tbsp per day. It could also pose particular risks for people with certain health conditions. Potential risks include:
Damage to tooth enamel: Over time, the acid in vinegar could erode the enamel on your teeth, leading to cavities. It’s best to dilute apple cider vinegar before consuming it and rinse your mouth with water. Crucially, avoid brushing your teeth for at least an hour after drinking vinegar, when your enamel is most fragile.
Skin burns: There are several examples of people who have experienced chemical burns after applying undiluted apple cider to skin.
Throat burns: The same principle applies to your throat. If you regularly drink vinegar without diluting it properly, it can lead to esophageal ulcers.
Slower digestion: Vinegar can increase the time it takes food to move from your stomach into your gut. This can lower your blood sugar and insulin levels, which could cause problems for people with type 1 diabetes.
Lower potassium levels: Apple cider vinegar may reduce the amount of potassium in your body, which is important for your overall health, although there is not much actual evidence to support this claim. People on medications that lower potassium, such as certain blood pressure drugs, may choose to avoid apple cider vinegar.
Apple cider vinegar is a good source of antioxidants and contains acetic acid that can kill some microbes. It also contains “good” bacteria that might have probiotic effects.
Research suggests it likely helps to regulate blood sugar levels, at least in people with type 2 diabetes.
When it comes to helping with weight loss or lowering “bad” cholesterol and blood fats, more research is needed.
So far, there seems to be no evidence to support claims that apple cider vinegar can reduce high blood pressure or treat acid reflux or acne.
When consumed or used on the skin undiluted, it comes with risks, but in the right quantities, it’s a great way to boost the flavor of a meal.
At ZOE, we know it’s best to eat a varied diet that includes lots of whole foods, fruits, and vegetables rather than focusing on single food items.
If you’d like to learn more about your gut microbiome and how your body responds to food, including blood sugar and blood fats, you can take our free quiz.
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