FACT CHECK: Can failing to brush your teeth damage your heart?

CLAIM:

Not brushing your teeth at night may increase the risk of cardiovascular disease by allowing harmful oral bacteria and plaque to build up, potentially triggering inflammation and affecting blood vessels and heart health over time. The claim also suggests that maintaining proper oral hygiene may help support long-term cardiovascular health.

FACT:

Current research suggests that poor oral hygiene, gum disease, and infrequent toothbrushing may be associated with a higher risk of cardiovascular problems through inflammation and oral bacteria entering the bloodstream. However, experts say there is no strong scientific evidence proving that skipping brushing at night directly causes heart disease, and most existing studies show correlation rather than direct causation. Maintaining good oral hygiene through regular brushing, flossing, and dental care may help support overall and cardiovascular health, but it should be viewed as one part of broader heart-healthy habits rather than a guaranteed way to prevent heart disease. 

In a recent Instagram post by the ‘naturalcures.ig’ page, which has nearly 1.3 lakh followers on Instagram, claims linking poor nighttime oral hygiene to heart disease risk have started gaining attention online. 

The post mentions that, “Study finds that not brushing your teeth at night increases your risk of cardiovascular disease.”

The caption of the post further claims that a simple nighttime dental routine may play a larger role in overall health than many people realise. According to the post, “your nighttime dental routine could be playing a crucial role in protecting your heart,” while also suggesting a “deep connection between daily oral hygiene and long-term cardiovascular wellness.”

The post states that skipping brushing before bed may allow harmful oral bacteria to multiply overnight, which could “trigger systemic responses that influence your circulatory health over time.” It further discusses what it describes as the “mouth-heart connection,” claiming that plaque buildup can contribute to gum irritation and inflammation, which may then release inflammatory markers into the bloodstream linked to arterial health problems.

The caption also refers to specific oral bacteria such as Porphyromonas gingivalis, stating that these bacteria “can enter the bloodstream through delicate gum tissue” and may interact with blood vessels in ways associated with plaque buildup in arteries.

Additionally, the post cites “a notable 2019 study published in the European Journal of Preventive Cardiology,” claiming that good oral hygiene has been associated with a lower risk of long-term cardiovascular problems, healthier blood pressure, and better arterial function. The post ultimately encourages people to improve their nighttime routine with brushing, flossing, and mouthwash, calling it “a simple, powerful daily habit that protects more than just your smile.”

Brushing teeth and cardiovascular link: What research says?

Growing research suggests that poor oral hygiene, gum disease, and infrequent toothbrushing may be associated with higher cardiovascular risk through inflammation and oral bacteria entering the bloodstream. However, most studies show correlation rather than direct proof that skipping brushing alone causes heart disease.

One widely discussed 2019 systematic review examined the role of Porphyromonas gingivalis, a bacterium strongly associated with periodontal disease. According to the researchers, “oral infections and systemic manifestations, or correlations between oral health and systemic diseases are a topic of discussion.” The review noted that P. gingivalis “plays an important role in the progression of periodontal disease” and may also have implications in “cardiovascular pathologies” along with rheumatoid arthritis and neurodegenerative diseases.

The study further stated that chronic oral inflammation, bacterial circulation in the bloodstream, and bacterial products “could be a further cause of system pathologies.” At the same time, the authors clearly acknowledged limitations, writing that “the major limitation of this study was represented by the fact of not having univocal results,” and that the findings were “purely descriptive/epidemiological.” The researchers concluded that maintaining oral health “can be a good starting point” for supporting general health, but stopped short of establishing a direct causal relationship between brushing habits and heart disease.

Further evidence came from a large 2020 population-based study involving over 1.61 lakh participants from the National Health Insurance System-Health Screening Cohort. Researchers investigated oral hygiene indicators including periodontal disease, toothbrushing frequency, professional dental cleaning, and missing teeth, while tracking cardiovascular outcomes over a median follow-up period of 10.5 years.

The study found that brushing teeth frequently - defined as three or more times a day - was associated with a lower risk of atrial fibrillation and heart failure. According to the researchers, “improved oral hygiene care was associated with decreased risk of atrial fibrillation and heart failure.” The study also reported that professional dental cleaning showed a protective association, while having a high number of missing teeth was linked to increased heart failure risk.

However, the authors described these findings as associations rather than proof of direct cause and effect. The study concluded that “healthier oral hygiene by frequent tooth brushing and professional dental cleaning may reduce risk of atrial fibrillation and heart failure.”

Research specifically exploring nighttime brushing habits was published in 2023. The study investigated whether the timing of toothbrushing affected cardiovascular disease risk among 1,675 hospitalised adult patients. Participants who brushed their teeth at night, either alone or along with morning brushing, showed better cardiovascular outcomes compared to those who did not brush at night.

According to the researchers, “our findings clearly indicate that only brushing in the morning after waking up is inadequate and that brushing at night is good to maintain good health.” The authors suggested that reduced saliva production during sleep may allow oral bacteria to multiply more easily overnight, potentially increasing bacterial load and inflammation.

At the same time, the study included several important limitations. Researchers acknowledged that the study only involved hospitalised patients, meaning the findings “cannot be generalised to healthy populations.” The paper also noted the possibility of selection bias, a relatively short observation period, and the inability to objectively measure brushing quality or plaque levels. The authors concluded that “the complete mechanism is unknown” and stated that larger multicentre studies are needed to generalise the findings.

Another 2024 study analysing over 13,000 adults from the Korean National Health and Nutritional Examination Survey examined the relationship between toothbrushing frequency, cardiovascular risk factors, and inflammation markers. Researchers observed that estimated 10-year cardiovascular risk was higher among participants who brushed their teeth less frequently.

However, after adjusting for multiple confounding factors such as age, sex, lifestyle, and underlying health conditions, researchers found that inflammatory markers -  rather than traditional cardiovascular risk factors -  remained significantly associated with brushing frequency. The study concluded that “reduced systemic inflammatory burden may explain the benefit of improved oral hygiene in terms of cardiovascular risk.”

More recent findings published in 2025 also reported similar trends. Using data from the First National Health Examination Survey, researchers found that individuals with poor oral health behaviours, defined as brushing once daily or less along with infrequent dental visits, had a higher prevalence of diabetes and elevated cardiovascular risk.

The study stated that “regular tooth brushing may act in prevention for diabetes and cardiovascular risk,” though researchers again described the findings as observational associations rather than definitive proof that brushing alone prevents cardiovascular disease.

The broader scientific discussion has also been acknowledged by major health organisations. According to the American Heart Association (AHA), previous studies have found links between periodontal disease, gum inflammation, and cardiovascular disease risk. One AHA-reported study suggested that people who brushed less than twice daily for under two minutes had a roughly three-fold increased cardiovascular risk compared to those brushing more regularly.

Still, experts quoted by the AHA cautioned against overinterpreting the findings. Dr Ann Bolger, cardiologist and professor emeritus at the University of California, San Francisco, noted that “it is possible that people who are very attentive to their dental health are also very attentive to other aspects of their health.” She further explained that chronic inflammation associated with gum disease “seems to be a very powerful predictor of cardiovascular disease.”

Similarly, Harvard Health Publishing stated that while several studies have found links between periodontal disease and systemic illnesses, including heart disease, “an ‘association’ is not the same as causation,” adding that “we’ll need additional research to figure out the importance of these observations.”

What experts say

Dr Sanjay Bhat said that current scientific evidence does not prove that skipping nighttime brushing directly causes cardiovascular disease, though several studies have shown an association between poor oral hygiene and heart-related problems.

According to Dr Bhat, “there is currently no compelling scientific evidence that failing to brush at night can on its own directly cause cardiovascular disease,” adding that most available research demonstrates “an association between these two issues rather than a definitive causal link.”

He explained that poor oral hygiene can contribute to gum disease, inflammation, and bacterial growth inside the mouth. “From these unhealthy gums some bacteria may then travel via the blood to cause inflammation not only in the oral cavity but also in the heart and blood vessels,” he said.

Dr Bhat further noted that brushing teeth at night becomes particularly important because saliva production naturally decreases during sleep. “Nighttime brushing and cleaning your teeth is mainly critical because it is during these hours that there is less saliva in our mouths to neutralise the bacteria and plaque buildup,” he explained.

Discussing the role of oral bacteria, Dr Bhat referred to Porphyromonas gingivalis, a bacterium associated with severe gum disease. According to him, when gums bleed or become infected, bacteria from the mouth may enter the bloodstream and potentially contribute to inflammation inside arteries. He said these bacteria “may act as a trigger for internal arterial inflammation,” which researchers believe could be linked to cardiovascular problems over time. However, he stressed that “the connection is still being researched and there is no direct correlation between the two from simply having gum disease.”

Dr Bhat also pointed out that many people with poor oral hygiene may already have other major cardiovascular risk factors, including smoking, diabetes, obesity, poor diet, lack of exercise, and stress. Because of this, he said, existing studies often struggle to separate oral health from broader lifestyle-related risks.

“What current studies do suggest is that taking care of one’s mouth may be beneficial in reducing cardiovascular risk, but the evidence still needs to be strengthened,” he said. He added that brushing, flossing, regular dental visits, and professional cleaning help reduce plaque, bacteria, infection, and inflammation inside the mouth, which may indirectly support overall cardiovascular health.

At the same time, Dr Bhat emphasised that oral hygiene should not be viewed as a guaranteed way to prevent heart disease. “Good oral health should be considered as an aspect, not the entirety, of being in good cardiovascular health,” he said.

He added that further long-term research is still needed to fully understand how oral bacteria and inflammation may affect blood vessels and heart health over time.

This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS