Alcohol use and smoking are significantly linked to higher rates of both breast cancer and atrial fibrillation, or irregular heartbeat, in women ages 55 and older across multiple global regions, according to new research published today in the Journal of the American Heart Association. The study, which analyzed data from 204 countries and territories, found that in about 40% of those regions, rates of the two conditions were similar among older women, with the highest-risk zones concentrated in Western nations.
Researchers evaluated 58 shared and distinct risk factors—including smoking, alcohol use, body mass index, and physical activity—using the Global Burden of Disease 2021 database. After accounting for multiple variables, smoking and alcohol use emerged as key contributors to both conditions. The analysis estimated that reducing alcohol intake and smoking could potentially lower the global risk of breast cancer by about 15% and atrial fibrillation by about 12%.
“Identifying shared risk factors is important for developing interventions that support optimal health, such as smoking cessation and alcohol restriction, which could potentially reduce the global incidence of breast cancer and atrial fibrillation/flutter substantially,” said study co-author Shu Wang, M.D., Ph.D., director of the Breast Disease Center at Peking University People’s Hospital in Beijing.
The study revealed that high-income and developed nations—including the U.S., Canada, Australia, New Zealand, and much of Europe—exhibited elevated rates of both conditions. This aligns with previous research linking Western diets and sedentary lifestyles to increased risks of cardiovascular and metabolic conditions and cancer. “One of the most surprising aspects of our findings was how common both breast cancer and atrial fibrillation/flutter diagnoses were among women ages 55 and older in high-income regions, which highlights the influence of lifestyle,” Wang said.
This is the first study to combine global data with machine learning to map the co-occurrence of breast cancer and atrial fibrillation and identify region-specific risk drivers. The newly developed spatial risk maps can help guide customized prevention strategies. According to co-authors Zeye Liu, M.D., Ph.D., and Yi Shi, M.D., Ph.D., both of Peking University People’s Hospital, “Breast cancer and atrial fibrillation/flutter rise together across many regions of the world and share the same modifiable risk factors. From a cardiovascular perspective, this means that reducing smoking and alcohol use could help lower the risk of both conditions at the same time.”
Laxmi Mehta, M.D., FAHA, chair of the American Heart Association’s Council on Clinical Cardiology, who was not involved in the study, noted that many of the same modifiable factors—smoking, alcohol use, poor diet, physical inactivity, and obesity—contribute to both breast cancer and cardiovascular disease. “This overlap underscores the importance of integrated lifestyle strategies to reduce risk,” Mehta said. The American Heart Association’s Life’s Essential 8 highlights key behaviors and health factors essential for prevention.
Study limitations include the use of country-level data that may vary in quality and the inability to prove direct cause and effect. The researchers plan to incorporate long-term, genetic, and socioeconomic data in future analyses to develop individualized and region-specific prevention strategies.
