What is the bad side of apple cider vinegar?

October 18, 2025 •

4 min read

According to a case report published in the journal Nephron, a young woman who drank large amounts of apple cider vinegar for six years developed osteoporosis and dangerously low potassium levels. This extreme example highlights some of the potential downsides, so what is the bad side of apple cider vinegar, and what should consumers be aware of?

Quick Summary

The high acidity of apple cider vinegar can cause tooth enamel erosion, throat irritation, and digestive distress. Chronic, excessive use may lead to low potassium levels and bone density issues. It can also interfere with certain medications and cause chemical burns if applied undiluted to the skin.

Key Points

Tooth Enamel Erosion: The high acidity of apple cider vinegar can permanently damage and wear away tooth enamel over time.
Digestive Issues: ACV may cause or worsen heartburn, acid reflux, and nausea, especially when taken undiluted or in large quantities.
Low Potassium Levels: Excessive, long-term use can lead to hypokalemia, causing muscle weakness, fatigue, and potential heart rhythm problems.
Drug Interactions: ACV can negatively interact with medications for diabetes and heart conditions, as well as diuretics and laxatives.
Throat and Skin Burns: Drinking undiluted ACV can burn the esophagus, while applying it to the skin can cause chemical burns.
Potential Bone Loss: In rare but documented cases of chronic, heavy use, ACV has been linked to a reduction in bone density.

The potential health risks associated with apple cider vinegar (ACV) are a crucial topic for anyone considering its regular consumption. While its proponents often highlight purported benefits like blood sugar control and weight management, the negative effects stemming from its high acidity and potential for overuse can be significant. Understanding these downsides is key to making informed decisions about its use.

Dental Erosion and Oral Health

One of the most documented and irreversible side effects of regular ACV consumption is the damage it can cause to your teeth. The primary active compound, acetic acid, is powerful enough to wear away tooth enamel over time. This damage is permanent and can lead to a host of problems.

How ACV Affects Tooth Enamel

Weakens Enamel: Acetic acid lowers the pH level in your mouth, softening the protective enamel and making it vulnerable to erosion.
Increases Sensitivity: As the enamel thins, it exposes the sensitive dentin layer underneath, causing increased sensitivity to hot, cold, and sweet foods.
Causes Discoloration: Eroded enamel can make teeth appear yellowish or translucent as the underlying dentin becomes more visible.
Increases Cavity Risk: With enamel compromised, your teeth are more susceptible to decay and the formation of cavities.

Digestive System Irritation

Despite being used by some to aid digestion, ACV can cause significant issues, especially for those with sensitive stomachs or pre-existing gastrointestinal conditions. The high acidity can be a major irritant.

Potential Gastrointestinal Side Effects

Throat and Esophageal Burns: Drinking undiluted ACV can cause irritation and even chemical burns to the delicate lining of the esophagus and throat.
Heartburn and Reflux: For people with Gastroesophageal Reflux Disease (GERD), ACV can worsen symptoms by increasing the stomach's acidity.
Nausea and Upset Stomach: Consuming too much, especially on an empty stomach, can lead to feelings of nausea, stomach distress, and indigestion.
Delayed Gastric Emptying: ACV can slow down the rate at which food leaves the stomach, a condition called gastroparesis. This can be particularly problematic for individuals with diabetes, leading to unpredictable blood sugar levels.

Potassium Depletion and Bone Health

Chronic and excessive consumption of ACV has been linked to decreased potassium levels in the blood, a condition known as hypokalemia. This can have serious health consequences.

The Link to Low Potassium and Bone Loss

In one extreme case, a woman who drank large quantities of ACV daily for several years developed severe low potassium and osteoporosis. While this is a rare outcome, it illustrates a potential danger of overuse. Low potassium can lead to fatigue, muscle cramps, and irregular heart rhythms. The proposed mechanism for bone loss is that the body leaches minerals from bones to help neutralize the high level of acid introduced by large ACV doses.

Drug Interactions

ACV can interfere with several types of medications, and individuals on these prescriptions should consult a doctor before starting a regimen.

Medication Interactions to Watch Out For

Diabetes medications (e.g., insulin): Since ACV can lower blood sugar, taking it with these medications could cause blood sugar levels to drop dangerously low.
Diuretics (water pills): Diuretics can lower potassium levels, and combining them with ACV, which also depletes potassium, can lead to excessively low potassium levels (hypokalemia).
Digoxin: This medication for heart conditions also interacts negatively with low potassium levels. Combining it with ACV can increase the risk of digitalis toxicity.

Comparison of Benefits vs. Risks


Aspect	Purported Benefits (Requires Research)	Potential Risks (Proven & Anecdotal)
Dental Health	N/A	Tooth enamel erosion, tooth sensitivity, decay
Digestion	Aids digestion, introduces probiotics	Throat irritation, heartburn, nausea, gastroparesis
Blood Sugar	May lower blood glucose levels	Hypoglycemia, especially when combined with medication
Weight Management	May aid weight loss by suppressing appetite	No solid evidence for long-term appetite suppression
Nutrient Levels	Minimal nutritional content	Depletion of potassium and potential bone loss
Topical Use	May help with skin conditions (diluted)	Chemical burns, skin irritation (undiluted)

Safely Incorporating ACV (If You Choose To)

For those who still wish to use ACV, taking precautions is essential to mitigate the potential damage. Always prioritize safety and consult a healthcare provider.

Best Practices for Consumption

Dilute Heavily: Always mix ACV with a large glass of water. A ratio of 1-2 tablespoons per 8 ounces of water is often recommended.
Use a Straw: To protect tooth enamel, drink the mixture through a straw to minimize contact with your teeth.
Rinse After Use: Swish your mouth with plain water immediately after consumption to neutralize the acid.
Avoid On an Empty Stomach: Taking ACV with a meal can reduce potential stomach irritation.
Monitor Your Body: Pay attention to how your body responds and scale back or stop if you experience any adverse effects like heartburn or stomach discomfort.
Avoid Pills: There are reports of ACV pills getting lodged in the throat and causing burns. Liquid, diluted ACV is the safer option.

Conclusion

While apple cider vinegar has been hailed as a natural remedy for various ailments, the bad side of apple cider vinegar is substantial and should not be overlooked. Its high acidity poses risks to dental health and can irritate the digestive system. Furthermore, excessive, long-term use can lead to serious health complications like hypokalemia and bone density issues, particularly for individuals on certain medications. The key takeaway is moderation and caution. Always dilute it heavily, protect your teeth, and consult a healthcare professional, especially if you take other medications or have underlying health conditions. By understanding the full spectrum of its effects, consumers can make a more informed and safer choice regarding its use.

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For more information on the potential risks and interactions with medications, it is wise to consult a medical resource like WebMD.

Frequently Asked Questions

Yes, apple cider vinegar can cause significant harm to your teeth due to its high acidity. The acetic acid can erode tooth enamel, leading to increased sensitivity, discoloration, and a higher risk of cavities over time.

For some people, especially those with sensitive stomachs or pre-existing conditions like GERD, apple cider vinegar can cause heartburn, acid reflux, nausea, and indigestion. It may also slow down digestion for some individuals.

No, it is highly inadvisable to drink apple cider vinegar straight. Its high concentration of acetic acid can cause severe irritation and chemical burns to the esophagus and throat.

Yes, excessive or prolonged consumption of apple cider vinegar has been shown to lower potassium levels in the blood, a condition called hypokalemia. This risk is higher for those taking diuretics or other medications that also affect potassium.

To consume ACV safely, always dilute it heavily with water, drink it through a straw to protect your teeth, and rinse your mouth with plain water afterward. Never exceed 1-2 tablespoons per day and consider taking it with a meal.

ACV pills are not necessarily safer. There have been reported cases of ACV tablets getting lodged in the throat and causing acid burns. The liquid, diluted form is generally considered the safer option.

Yes, ACV can interact with certain medications, including diabetes drugs (like insulin), diuretics, and digoxin. These interactions can lead to dangerously low blood sugar or low potassium levels.