Oral Health Side Effects of the Keto Diet: Bad Breath & Dry Mouth

Oral Health Side Effects of the Keto Diet: Bad Breath & Dry Mouth
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Oral Health Side Effects of the Keto Diet: Bad Breath & Dry MouthClinical Content Reviewed by Dr. Jay Khorsandi, DDS
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Table of Contents

  1. What is the Keto Diet?
  2. Pros & Cons
  3. Symptoms
  4. Why Ketos Causes Bad Breath
  5. How Long Does It Last?
  6. Keto Breath & Dry Mouth
  7. How to Get Rid of It
  8. Prevention
  9. Frequently Asked Questions
  10. References

Increasing your physical activity and changing your diet can help you reach a weight-loss goal. But altering what you eat and how you eat requires more than reducing your calorie intake. It also requires adjusting the types of food you eat. Any food and drink alterations can cause certain side effects besides the loss of weight.

One example is the Keto Diet, or ketogenic diet, a relatively new way of eating that is gaining popularity in much the same way the Atkins diet gained a following more than a decade ago.

The Keto Diet is a moderate-protein, high-fat, low-carb diet that was designed to help a person achieve ketosis. But while it and other low-carb eating plans have proved successful in helping people lose weight faster, one of its side effects is so-called “keto breath."

Keto breath is just what it sounds like — bad breath as a result of the foods you are eating and not eating.
Obviously, it’s not a positive side effect. Here is what you need to know about all the side effects, symptoms and how to get rid of them.

What Is the Ketogenic Diet?

The Keto Diet offers several health benefits through the consumption of foods with high fat and low carbohydrates. In fact, the diet replaces carbs with fats.

With a reduction of carbs, your body goes into a metabolic state called ketosis. This state has your body become efficient at burning fat for energy and turns the fat into ketones in the liver, which supplies your brain with energy.

Proponents say the diet improves a person's health as well as helps them lose weight. Ketogenic diets may help against epilepsy, Alzheimer's disease, diabetes and cancer.

Pros and Cons of the Keto Diet on Your Oral Health

Keto breath is an odor or distinct taste in your mouth that is different from typical bad breath. People have described keto breath as a metallic taste or a funny taste in your mouth. The keto breath can also be described as being similar to nail polish or even a fruity smell.

When you enter full ketosis, and your body is completely burning fat as an energy source instead of carbs, your blood will become elevated with ketones. The ketones are responsible for the acetone-scented or fruity smell to your breath, which you will not be able to alleviate with brushing.

There are a lot of benefits with the keto diet for your physical health, however, the side effects for oral health may be uncomfortable. Between having bad breath, and an odd taste lingering in your mouth, you will have to overcome these discomforts to achieve the physical benefits.

Symptoms of Keto Breath

Keto breath will leave you with a distinct odor or taste in your mouth, one different than ordinary bad breath. Many people who undertook the keto diet reported experiencing a metallic taste in their mouth. Others describe it as a more distinctive taste, such as nail polish remover, or a fruity taste.

Why Does the Keto Diet Cause Bad Breath?

Why does the Keto Diet have a bad-breath side effect? Because all low-carb diets do.

Your body receives energy from a lot of food sources, including carbohydrates, protein and fat. It breaks down glucose or carbs first, for energy, then break down fat.

Because the Keto Diet and other low-carb diets restrict your intake of carbs, your body must use stored fats for energy. When your body is forced to use these fats, breaking them down to gain energy.

Fatty acids are turned into ketones, natural chemicals produced when fat is burned for energy. Ketones are typically harmless, and your body releases them through urination and exhalation. The ketones cause the resulting bad breath.

There are three primary ketones:

  • 3-hydroxybutyrate (3-OHB)
  • Acetoacetate
  • Acetone

Acetone is a key ingredient in nail polish remover. If your breath starts to smell like polish remover, it indicates that you are in a state of ketosis.

How Long Does Keto Breath Last?

Not all people who go on a Keto Diet experience keto breath. And even if you do, while it may be troublesome it should only last a short time. You will notice a change in your breath within days, or perhaps a week after starting the diet, but the odor will go away as your body adjusts to your lower-carb intake.

Typically, within a couple of weeks, the odd tastes and odor will disappear. During the couple of weeks when your body is adjusting to your new diet, there are a few things you can do to mask the tastes and bad breath.

Risk of Keto Breath and Dry Mouth

Another Keto Diet side effect is dry mouth. Much like bad breath, dry mouth is to be expected when you increase your fat intake and slash your consumption of carbs.

Why? Because the transition takes a toll on your body. Your metabolism is going to shift during the first couple of weeks of ketosis, and your body will undergo changes in fluid balance and electrolytes. When this process happens, you can become excessively thirsty and find yourself urinating more than usual. It is important to consume a lot of water when on this diet.

How to Get Rid of Keto Breath

Here are tips to help you get rid of keto breath:

  • Increase your water intake
  • Eat less protein
  • Chew sugarless gum
  • Suck on sugarless mints
  • Increase carb intake
  • Use good oral hygiene methods
Drink More Water
Drinking more water will help dilute the concentration of ketones that contribute to bad breath. When drinking water, swish it around in your mouth, allowing it to moisten your teeth, cheeks and gums and to help remove food particles that can contribute to breath odors.
Eat Less or Different Protein

Eating protein is important when you go on a low-carb diet, but eating too much protein will increase the risks of bad breath. When your body breaks down protein, it produces ammonia, which is another byproduct eliminated through exhalation and urination. An ammonia odor can create significantly bad breath.

Diet experts like you to keep your protein mix at 30 to 35 percent of your daily caloric intake. If you are eating more and cut back, you can ease up on that dragon breath.

Similarly, varying your protein sources will alter the ketones that get produced. That, too, will adjust the odor they produce.

Use Sugarless Gum and Mints
Gum and mints can help mask bad breath created when on a keto diet while your body adjusts to the low-carb diet. These mints and gum should be sugar-free. There are mints that contain Xylitol that will kill the bacteria and will also help prevent cavities
Increase Your Carbs
If you increase your carb intake, you can eliminate keto breath. By increasing your daily amount of carbohydrates by just a small amount, you will remain in a state of ketosis. For example, if you are eating fifteen grams of carbs each day, increase the amount of your intake to twenty grams and see if your breath improves.
Upgrade Your Oral Care Regimen
It is important to brush your teeth every day, and especially important when on a keto diet. While brushing and flushing may not eliminate the symptoms of bad breath completely, it will reduce the odors coming from your mouth. If you don't brush, bacteria accumulate in your mouth which can trigger bad breath. Poor dental hygiene can worsen the effects of keto breath.
Other Tips

Another way to banish bad breath is to chew basil or parsley, two natural herb breath fresheners.

If these solutions do not help you mask or dilute bad breath, contact your dentist to see if there is a more serious condition occurring.

Prevention of Keto Breath

It’s not likely that you can prevent keto breath if you opt for this low-carb diet. But one step you can try is to use a ketone breath analyzer to learn how much carbs you can consume without being kicked out of ketosis.

A ketone breath analyzer is a breath test to determine how many carbs you've consumed and let you know whether or not you are in fat-burning ketosis.

You can also wean yourself from carbs and gradually add more protein to stave off the development of bad breath. It’s not a guarantee, but the slowed-down changes also will slow down the weight-loss effect of the diet.

If you notice keto breath and are not on the keto diet, or other low-carb diets, eating more carbs can kick your system out of ketosis and eliminate bad breath.

Frequently Asked Questions

Does the Keto Diet affect your teeth?
When following a keto diet, it can affect your oral health, and teeth as it will reduce the amount of plaque build-up.
Does keto help gum disease?
The Keto Diet has you eating fewer carbs, so your mouth will experience less inflammation that can affect your gums. Theoretically, when you decrease your carb intake, it can lead to a decrease in the risk of periodontal symptoms.
Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.