You may want to avoid using mouthwash after a workout. Researchers from the United Kingdom and Spain have found the product could block an important effect of exercise that helps lower blood pressure.
Exercise helps improve blood pressure through the process called vasodilation. It occurs when blood vessels open in response to the higher levels of nitric oxide and leads to higher blood flow circulation to active muscles, ScienceAlert reported.
Researchers previously believed that vasodilation only happens during exercise. But studies conducted in the recent years showed the improved blood circulation and lower blood pressure remain even after the physical activity.
That is because of bacteria that work with a compound called nitrate, which appears when nitric oxide degrades.
“Research over the last decade has shown that nitrate can be absorbed in the salivary glands and excreted with saliva in the mouth,” Raul Bescos, a physiology specialist from the University of Plymouth, said. “Some species of bacteria in the mouth can use nitrate and convert into nitrite – a very important molecule that can enhance the production of nitric oxide in the body.”
Swallowing saliva with nitrite could help keep blood vessels wide after exercise. However, some people may be blocking the benefit because of their oral hygiene.
A study, published in Free Radical Biology and Medicine, found that using antibacterial mouthwash after exercise could disrupt the production of nitrite. Researchers said the product could even lead to zero reduction in blood pressure.
The team tested the effects of mouthwash with 23 healthy adults in 2019. The participants were asked to run on a treadmill for 30 minutes and were later divided into groups depending on the product they used to rinse their mouth after the workout.
Researchers also monitored their blood pressure during the experiment, after the exercise and during their rest period. Results showed that using antibacterial mouthwash one hour after an exercise could only reduce systolic blood pressure by an average of –2.0 mmHg.
Those who did not use the product in the same period showed higher reduction of –5.2 mmHg. Two hours after the treadmill session, the mouthwash group also appeared without any signs of lower blood pressure, while the placebo group had significant reduction as an effect of exercise.
“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,” Craig Cutler, researcher from the University of Plymouth, said. “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.”