It is well known that regular physical exercise reduces the risk of getting heart disease, colon cancer, osteoporosis, hypertension, high cholesterol, and a range of other disorders. Now, a report in the Journal of Dentistry, shows that physical activity may also reduce the risk of contracting periodontitis. The study looked at a group of American subjects, aged 18 and older, who had had a periodontal examination and reported similar physical activity — or inactivity — for a period of 10 years or longer. The researchers, led by Mohammad S. Al-Zahrani of the Faculty of Dentistry at King Abdulaziz University in Saudi Arabia, then examined the relationship between physical activity and periodontitis. Their analysis adjusted for various factors, such as age, gender, race, education, body mass index, and smoking. The report concluded that engaging in the recommended level of exercise is associated with lower periodontitis prevalence, especially among people who have never smoked and former smokers. People who never smoked and took regular exercise were about 54% less likely to have periodontitis than people who never smoked but did not engage in physical activity. Rather surprisingly, the prevalence of periodontitis in former smokers was 74% lower for physically active than inactive individuals. The positive effects of exercise, however, did not show a statistically significant benefit for those who smoked.