𧴠7 Side Effectsπ²
Of Too Much Apple Cider Vinegar
Written by Franziska Spritzler, RD, CDE
August 10, 2016
Apple cider vinegar is a natural tonic.
However, people have also raised concerns about its safety and possible side effects.
This article takes a look at apple cider vinegar's potential side effects.
It also provides instructions on how to consume apple cider vinegar safely.
What Is Apple Cider Vinegar?
Apple cider vinegar is made by combining apples with yeast.
The yeast then converts the sugar in the apples into alcohol. Bacteria are then added to the mixture, which ferment the alcohol into acetic acid (1).
Acetic acid makes up about 5–6% of apple cider vinegar. It is classified as a "weak acid," but still has fairly strong acidic properties when it is concentrated. In addition to acetic acid, vinegar contains water and trace amounts of other acids, vitamins and minerals (1).
Several studies in animals and humans have found that acetic acid and apple cider vinegar may promote fat burning and weight loss, decrease blood sugar levels, increase insulin sensitivity and improve cholesterol levels (2, 3, 4, 5, 6, 7, 8).
Bottom Line:
Apple cider vinegar is made from acetic acid, which may provide several health benefits. These include weight loss, lower blood sugar and healthier cholesterol levels.
Unfortunately, apple cider vinegar has been reported to cause some side effects.
This is particularly true in large doses.
Although small amounts are generally fine and healthy, taking too much can be harmful and even dangerous.
1. Delayed Stomach Emptying
Apple
cider vinegar helps prevent blood sugar spikes by reducing the rate at
which food leaves the stomach and enters the lower digestive tract. This
slows down its absorption into the bloodstream (9).
However, this effect may worsen symptoms of gastroparesis, a common condition in people with type 1 diabetes.
In
gastroparesis, the nerves in the stomach don't work properly, so food
stays in the stomach too long and is not emptied at a normal rate.
Symptoms of gastroparesis include heartburn, bloating
and nausea. For type 1 diabetics who have gastroparesis, timing insulin
with meals is very challenging because it's hard to predict how long it
will take food to be digested and absorbed.
One controlled study looked at 10 patients with type 1 diabetes and gastroparesis.
Drinking
water with 2 tablespoons (30 ml) of apple cider vinegar significantly
increased the amount of time that food stayed in the stomach, compared
to drinking plain water (10).
Bottom Line:
Apple cider vinegar has been shown to delay the rate at which food leaves the stomach. This may worsen symptoms of gastroparesis and make blood sugar control more difficult for people with type 1 diabetes.
2. Digestive Side Effects
Apple cider vinegar may cause unpleasant digestive symptoms in some people.
Human
and animal studies have found that apple cider vinegar and acetic acid
may decrease appetite and promote feelings of fullness, leading to a
natural reduction in calorie intake (11, 12, 13).
However, one controlled study suggests that in some cases, appetite and food intake may decrease due to indigestion.
The
people who consumed a drink containing 25 grams (0.88 oz) of apple
cider vinegar reported less appetite but also significantly greater
feelings of nausea, especially when the vinegar was part of an
unpleasant-tasting drink (14).
Bottom Line:
Apple cider vinegar may help reduce appetite, but may also cause
feelings of nausea, particularly when consumed as part of a drink with
bad flavor.
3. Low Potassium Levels and Bone Loss
There are no controlled studies on apple cider vinegar's effects on blood potassium levels and bone health at this time.
However,
there is one case report of low blood potassium and bone loss that was
attributed to large doses of apple cider vinegar taken over a long
period of time.
A 28-year-old woman consumed 8 oz (250 ml) of apple cider vinegar diluted in water on a daily basis for six years.
She was admitted to the hospital with low potassium levels and other abnormalities in blood chemistry (15).
What's more, the woman was diagnosed with osteoporosis, a condition of brittle bones that is rarely seen in young people.
Doctors
who treated the woman believe the large daily doses of apple cider
vinegar led to minerals being leached from her bones to buffer the
acidity of her blood.
They also noted that high acid levels can reduce the formation of new bone.
Of
course, the amount of apple cider vinegar in this case was much more
than most people would consume in a single day — plus, she did this
every day for many years.
Bottom Line: There is one case report of low potassium levels and osteoporosis likely caused by drinking too much apple cider vinegar.
4. Erosion of Tooth Enamel
Acidic foods and beverages have been shown to damage tooth enamel (16).
Soft
drinks and fruit juices have been more widely studied, but some
research shows the acetic acid in vinegar may also damage tooth enamel.
In
one lab study, enamel from wisdom teeth was immersed in different
vinegars with pH levels ranging from 2.7–3.95. The vinegars led to a
1–20% loss of minerals from the teeth after four hours (17).
Importantly,
this study was done in a lab and not in the mouth, where saliva helps
buffer acidity. Nevertheless, there’s some evidence that large amounts
of vinegar may cause dental erosion.
A case study also concluded
that a 15-year-old girl’s severe dental decay was caused by consuming
one cup (237 ml) of undiluted apple cider vinegar per day as a weight loss aid (18).
Bottom Line: The acetic acid in vinegar may weaken dental enamel and lead to loss of minerals and tooth decay.
5. Throat Burns
Apple cider vinegar has the potential to cause esophageal (throat) burns.
A
review of harmful liquids accidentally swallowed by children found
acetic acid from vinegar was the most common acid that caused throat
burns.
Researchers recommended vinegar be considered a “potent caustic substance” and kept in childproof containers (19).
There are no published cases of throat burns from apple cider vinegar itself.
However,
one case report found that an apple cider vinegar tablet caused burns
after becoming lodged in a woman’s throat. The woman said she
experienced pain and difficulty swallowing for six months after the
incident (20).
Bottom Line:
The acetic acid in apple cider vinegar has caused throat burns in
children. One woman experienced throat burns after an apple cider
vinegar tablet became lodged in her esophagus.
6. Skin Burns
Due to its strongly acidic nature, apple cider vinegar may also cause burns when applied to the skin.
In
one case, a 14-year-old girl developed erosions on her nose after
applying several drops of apple cider vinegar to remove two moles, based
on a protocol she’d seen on the internet (21).
In
another, a 6-year-old boy with multiple health problems developed leg
burns after his mother treated his leg infection with apple cider
vinegar .
There are also several anecdotal reports online of burns caused by applying apple cider vinegar to the skin.
Bottom Line: There have been reports of skin burns occurring in response to treating moles and infections with apple cider vinegar.
7. Drug Interactions
A few medications may interact with apple cider vinegar:
- Diabetes medication:
People who take insulin or insulin-stimulating medications and vinegar
may experience dangerously low blood sugar or potassium levels.
- Digoxin (Lanoxin):
This medication lowers your blood potassium levels. Taking it in
combination with apple cider vinegar could lower potassium too much.
- Certain diuretic drugs:
Some diuretic medications cause the body to excrete potassium. To
prevent potassium levels from dropping too low, these drugs shouldn’t be
consumed with large amounts of vinegar.
Bottom Line: 
