Some people who suffer from acne drink apple cider vinegar as a natural remedy in an attempt to control it. While anecdotal reports mostly indicate that apple cider vinegar provides little effect on acne, there is some scientific evidence which suggests that vinegar might be somewhat helpful in managing acne due to its ability to reduce blood sugar levels and provide the body with antioxidants.
First, let’s look at what vinegar is, and then we’ll consider how it might be useful in treating acne.
What Is Vinegar?
Vinegar is a natural food product that is made by a process called fermentation. Fermentation uses yeast and bacteria to convert sugar into alcohol and acids. Vinegar-fermentation is a two-step process:
- In the first step, yeast converts sugar from a carbohydrate-containing food, such as apples, grapes, and grains, into alcohol.
- In the second step, a type of bacteria called Acetobacter turns the alcohol into acetic acid, which is the main component of vinegar.1-4
Fermentation of different foods results in different kinds of vinegar. For example, fermenting apple cider results in apple cider vinegar. Fermenting wine results in wine vinegar. And fermenting berries results in berry vinegar.1,3,4
Interestingly, while most vinegar is produced commercially, anyone can make vinegar at home. According to one chapter in the book series Advances in Applied Microbiology from 1976, “[n]early any unfortified wine or beer when exposed to the atmosphere will develop an acidity which, in many cases, results from the action of Acetobacter in converting the ethanol to acetic acid. Under normal household conditions, the conversion occurs quite slowly and there are no sharp lines of demarcation between the categories of wine, old wine, sour wine, and vinegar.”2
Vinegar is mostly water and acetic acid, but it contains a variety of other compounds in small amounts, including vitamins, mineral-salts, amino acids (molecules that form the basis of proteins), various acids, such as lactic, citric, and malic acids, and a group of compounds called flavonoids. These additional compounds give vinegar its characteristic flavor. Acetic acid and flavonoids also could contribute to the healing of acne. We will discuss these effects later in the article.2,5,6
How Has Vinegar Been Used in Medicine?
People have used vinegar medicinally for more than five thousand years for a variety of ailments, including the following:
- In 400 B.C., Hippocrates, a Greek doctor who is considered to be the father of modern medicine, prescribed a mixture of honey and apple cider vinegar in an attempt to cure diseases.3
- Since the late 18thcentury, doctors have used vinegar to help prevent and treat obesity.1
- During the American Civil War, in the 1860s, doctors used apple cider vinegar to disinfect soldiers’ wounds.3
More recently, according to a 2016 review article in the journal, Current Opinion in Food Science, “Several studies have reported acetic acid is a bioactive compound that exhibits various therapeutic values. Up to date, vinegar has been reported not only for [reducing] obesity, but also shown to exhibit therapeutic effects on diabetes, cardiovascular disorders, and cancer.”1
How Might Drinking Vinegar Treat Acne?
As we have read, vinegar carries potentially therapeutic effects for a range of conditions. In the following sections, we will explore how vinegar:
- Counteracts the negative effects that a poor diet may have on acne.
Protects the skin from damage caused by harmful molecules called free radicals, which may worsen inflammatory acne.
Researchers have debated for years whether diet plays a role in acne development or not. Until recently, while many scientists had believed that diet contributed to acne, there was no evidence of this. In fact, the Academy of Dermatology’s guidelines of 2007 indicated that there was no direct link between diet and acne. However, in more recent years, evidence has been accumulating which suggests a link between diet and acne.7
Three processes in which vinegar might help reduce acne development are:
- Counteracting a high-sugar diet
- Counteracting a diet high in fatty acids
Counteracting a High-Sugar Diet
A series of clinical studies, reviewed in both a 2009 article in Dermato-Endocrinology and a 2009 article in the International Journal of Dermatology, indicated that a diet rich in sugar might influence acne by two different processes, both involving a hormone called insulin.7,8One of the studies was a randomized controlled trial, which is a rigorous study that provides the most trustworthy evidence. Researchers examined whether a low-sugar diet reduced the number of acne lesions or not. They found that acne patients who consumed a diet low in sugar experienced:
- Greater reductions in acne lesions.
- An increase in insulin sensitivity, meaning that insulin functioned better.
- A decrease in the level of androgens (male hormones present in both males and females).7,8
Vinegar might help reduce insulin-spikes. This can keep levels of androgens in check, helping to alleviate acne symptoms.
Insulin is a hormone that the pancreas secretes. One of its primary functions is to maintain a steady blood-sugar level. When we eat, our blood-sugar levels rise. A high level of sugar in the blood results in increased levels of insulin.
High levels of insulin might affect acne by:
- Stimulating sebocytes (skin oil–cells), causing them to increase in number. This results in the production of more sebum, higher levels of sebum being associated with acne.
Insulin also reduces the amount of a protein called SHGB, which decreases the levels of androgens in the blood. When insulin is high, this protein can’t carry out its function, causing these levels to rise. And high levels of androgens is associated with the development of acne.7,8
A 2010 article in Medscape General Medicine reviewed two studies which indicated that acetic acid, the main component of vinegar, lowered blood-sugar levels. One study demonstrated that 4 tablespoons of strawberry vinegar, consumed with a meal, reduced post-meal blood-sugar by more than 20%. The other study found that consuming 1-½ tablespoons of white vinegar as salad dressing and a piece of white bread reduced it by more than 30%.9
While scientists still do not know exactly how acetic acid lowers blood-sugar, they believe it inhibits digestive enzymes (molecules that speed up chemical reactions), which break food down into sugars. By inhibiting these enzymes, acetic acid reduces the production of sugars. And because blood-sugar affects acne, it is reasonable to hypothesize that vinegar positively affects acne.9
Counteracting a Diet High in Fatty Acids
Another dietary factor that might contribute to acne is the amount and kinds of fatty acid in the diet. Vinegar might reduce harmful fatty acids in the blood to some degree.7,10During digestion, the body breaks down fats from food into fatty acids, which then enter the bloodstream. They travel through the bloodstream to sebocytes, where an enzyme called desaturase converts them into unsaturated fatty acids. This relates to acne because unsaturated fatty acids are non-comedogenic, meaning that they do not clog pores. If the levels of fatty acids in the blood are high, the capacity of desaturase becomes overwhelmed, and saturated (harmful) fatty acids accumulate in sebaceous glands, potentially contributing to the development of acne.
A 2012 study in Life Science Journal evaluated whether consuming apple cider vinegar affected the levels and types of fatty acids in the blood or not. They looked at a sample of people who contained high levels of fatty acids in their blood and had never taken medications in order to lower these levels. The researchers concluded, “The results of the present study indicated that 8 weeks of apple cider vinegar consumption significantly reduced harmful lipids, i.e. total cholesterol, LDL, and triglyceride.”10While cholesterol, LDL, and triglycerides are not fatty acids, they are fatty substances that are made up mostly of fatty acids, so it is reasonable to assume that vinegar has this effect on fatty acids as well.
Vinegar contains several antioxidants, including flavonoids. Antioxidants are molecules that prevent cell damage from molecules called free radicals. This is relevant to acne because the damage caused by free radicals on the skin can result in inflammation and breakouts. Antioxidants might help treat acne in this regard. They also protect the skin by preventing external toxins from penetrating beyond its outermost layer. A reduced number of antioxidants near the skin’s hair-follicles and oil-glands is thought to be implicated in the development of acne.
The antioxidant properties of vinegar might help with acne also by lowering cholesterol. Cholesterol contributes to the depletion of antioxidants, and as we read, vinegar does the converse.
According to a 2012 article in Life Science Journal, “Apple cider vinegar contains [compounds] that have beneficial health effects. Its antioxidant flavonoid content can reduce the harmful effects of high cholesterol diets.”10
Although there is no direct research on the relationship between vinegar’s antioxidant properties and acne, it is reasonable to hypothesize that vinegar is beneficial for acne in this regard.
What Vinegar Does Not Do – Dispelling the Myth of Vinegar As an Alkalinizing-Agent for the Body
Some people believe that consuming apple cider vinegar makes the body more alkaline (less acidic). This assertion is of no scientific merit. The body’s built-in balance of acidity and alkalinity takes care of this. The body is slightly alkaline, and the skin is slightly acidic. This balance is important enough so as to prioritize maintaining it over everything else, so in most cases, nothing can disrupt it.11
Is Vinegar Safe to Drink?
People have been consuming vinegar for thousands of years, and it is considered to be relatively safe. Generally, it is, but there are reports of rare, harmful effects of it on the gastrointestinal system. Since vinegar is acidic, drinking too much of it can result in inflammation of the esophagus (food pipe), which can lead to more serious complications over time. Vinegar also can cause wheezing and inflammation of the lungs if it enters them.
These side effects are rare, but as a 2006 article in Medscape General Medicine explains, “These complications attributed to vinegar are isolated occurrences, but with the increased interest in vinegar as adjunct therapy […], carefully controlled trials to examine potential adverse effects of regular vinegar ingestion are warranted.”9