Those who use mouthwash regularly are prone to heart attacks at a young age

How do you start your morning? You wake up and take care of your dental routine, which includes brushing your teeth, flossing, and later using a mouthwash. The result? You get pristine teeth, your gums are healthy, and the harmful microbes die forever! Well, that’s not all. Your dental care routine is possibly increasing your risk of a heart attack. A study has found the link between the use of mouthwash and its effect on inhibiting the benefits of exercise. Wondering how it is related to the increased risk of heart attacks? Hold on, let’s take a look.

A groundbreaking study from the University of Plymouth, published in Free Radical Biology and Medicine, reveals how mouthwash disrupts the body’s natural processes, and diminishes the cardiovascular benefits of exercise and possibly contributing to heart health risks over time. The peer-reviewed, randomized, double-blind crossover study conducted in humans found that the use of mouthwash could strip the benefits of exercise. Exercise is known to reduce blood pressure, however, the activity of bacteria in our mouths may determine whether we experience this benefit.

"Scientists already know that blood vessels open up during exercise, as the production of nitric oxide increases the diameter of the blood vessels (known as vasodilation), increasing blood flow to active muscles. What has remained a mystery is how blood circulation remains higher after exercise, in turn triggering a blood-pressure lowering response known as post-exercise hypotension,” lead author Dr. Raul Bescos, Lecturer in Dietetics and Physiology at the University of Plymouth, said in a statement.

Though previous research has suggested that nitric oxide was not involved in this post-exercise response, and was only involved during exercise, the new study challenges these views. Exercise is known to lower blood pressure through a process called vasodilation, where blood vessels widen to improve blood flow. According to the research, bacteria in the mouth play a critical role in converting exercise-induced nitrate into nitrite.

"Some species of bacteria in the mouth can use nitrate and convert it into nitrite - a very important molecule that can enhance the production of nitric oxide in the body. And when nitrite in saliva is swallowed, part of this molecule is rapidly absorbed into the circulation and reduced back to nitric oxide. This helps to maintain a widening of blood vessels, which leads to a sustained lowering of blood pressure after exercise. We wanted to see whether blocking nitrate's ability to convert into nitrite by inhibiting oral bacteria would have any effect on post-exercise hypotension,” Dr. Bescos added.


To understand this involved 23 healthy adults were asked to use a treadmill for 30 minutes. After exercising, participants rinsed their mouths with either an antibacterial mouthwash (0.2% chlorhexidine) or a placebo (mint-flavored water) at regular intervals. The results were striking! People who used the mouthwash saw a 60% reduction in the blood pressure-lowering effect of exercise within one hour, and the benefit was completely erased after two hours. In contrast, the placebo group experienced a significant blood pressure drop of 5.2 mmHg, which points to the critical role of oral bacteria.

"These findings show that nitrite synthesis by oral bacteria is hugely important in kick-starting how our bodies react to exercise over the first period of recovery, promoting lower blood pressure and greater muscle oxygenation. In effect, it's like oral bacteria are the 'key' to opening up the blood vessels. If they are removed, nitrite can't be produced, and the vessels remain in their current state. Existing studies show that, exercise aside, antibacterial mouthwash can actually raise blood pressure under resting conditions, so this study followed up and showed the mouthwash's impact on the effects of exercise. The next step is to investigate in more detail the effect of exercise on the activity of oral bacteria and the composition of oral bacteria in individuals under high cardiovascular risk. Long-term, research in this area may improve our knowledge for treating hypertension, or high blood pressure, more efficiently,” study co-author Craig Cutler, who conducted the research as part of his PhD at the University of Plymouth, added.

Increased blood pressure means your heart health is at risk. Over time, consistently elevated blood pressure (hypertension) is a major risk factor for heart attacks, even in younger individuals.