Research from the Million Women Study shows that even a small increase in weight can increase a woman’s risk of coronary heart disease.

Regular exercise and healthy eating won’t only shrink your waistline; it can also shrink your risk of coronary heart disease (CHD), according to an article published in BioMed Central’s open access journal BMC Medicine. In fact, research from the Million Women Study shows that even a small increase in weight can put you at a risk of CHD equivalent to the risk associated with getting older.

In this study, researchers from the University of Oxford followed the health of 1.2 million women from England and Scotland for nine years on average and found that the risk of CHD increases with Body Mass Index (BMI), “a measure of body fat based on height and weight that applies to adult men and women,” according to the National Heart Lung and Blood Institute, calculated as (weight in pounds/Height in inches2) x 703.

“We found that the risk of coronary heart disease increased progressively with increasing BMI, not only for obese women (BMI of 30 or more), but also for those who are more moderately overweight (BMI between 25 and 30),” said lead study author Dexter Canoy in an interview with Healthline. “CHD risk also increases with age; the additional risk associated with a 5 unit increase in BMI is similar to that conferred by getting older by 2.5 years.”

“One in eleven lean middle aged women, with an average BMI of 21, will be admitted to a hospital or will have died from CHD between the ages of 55 to 74. This risk progressively increases with BMI, and it reaches one in six, for obese women (with an average BMI of 34),” according to the study press release.

“Our findings suggest that even women who are only moderately overweight are at an increased risk of CHD,” Canoy said. “At the population level, even small declines in the prevalence of overweight and obesity could potentially prevent CHD for a large number of people.”

According to the Centers for Disease Control and Prevention, “more than one-third of U.S. adults are obese” and conditions related to obesity, including “heart disease, stroke, type 2 diabetes and certain types of cancer, are some of the leading causes of preventable death.”

“While we did not directly address lifestyle changes, our findings are in line with those of other studies that have shown that adopting a healthy lifestyle can help prevent heart disease,” Canoy said. “A healthy lifestyle includes not smoking, avoiding excess alcohol consumption, and maintaining a healthy weight through diet and physical activity.”

While this particular study focused on women’s health, obese and overweight men are also at a higher risk of CHD.

“Our estimate of CHD risk in relation to BMI (23 percent increase in CHD risk per 5 units of BMI increase) is generally comparable to those from studies that included men,” Canoy said. “In absolute terms, however, the CHD rate is higher in men than in women.”

According to the CDC, “heart disease is the leading cause of death for both men and women,” and in 2009, “more than half of the deaths due to heart disease were in men.”