Alcohol and smoking linked to breast cancer and irregular heartbeat in women, study finds
Smoking and alcohol were linked to breast cancer and irregular heartbeat in women aged 55 and over, a global analysis suggests.
Breast cancer and atrial fibrillation or flutter represent a growing global health burden, but the reasons for similar rates in some regions are not well understood.
Atrial fibrillation, also known as AFib, is an irregular heartbeat.
Study co-author Dr Shu Wang, director of the Breast Disease Center at Peking University People’s Hospital, said: “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.”
Researchers examined rates of breast cancer and atrial fibrillation or flutter among women aged 55 and over in 204 countries and territories.
They assessed exposure to 58 shared and distinct health, behavioural and lifestyle risk factors, including smoking, alcohol use, body mass index and physical activity.
The analysis found that 80 of 202 countries and territories, around 39 per cent, had similar rates of both conditions.
Breast cancer was the dominant condition in 65 countries, while atrial fibrillation or flutter was dominant in 57.
After accounting for multiple variables, smoking and alcohol use were linked to higher rates of both breast cancer and atrial fibrillation or flutter.
A further analysis estimated that reducing alcohol intake and smoking could potentially cut breast cancer risk by around 15 per cent and atrial fibrillation or flutter risk by about 12 per cent worldwide.
Alcohol use was estimated to contribute to 9.27 per cent of breast cancer cases and 7.57 per cent of atrial fibrillation or flutter cases.
High-income and developed countries, including the US, Canada, Australia, New Zealand and much of Europe, had elevated rates of both conditions.
The findings were consistent with previous research linking Western diets and sedentary lifestyles to greater risks of cardiovascular and metabolic conditions and cancer.
Wang said: “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.
“This is the first study combining global data with machine learning to show the relationship between the conditions, their location across the world and the shared risk factors of these two conditions.”
The highest-risk areas were mostly in Western countries, where exposure to smoking and alcohol was greater than in Eastern regions.
Researchers said the pattern could reflect lifestyle, social and community differences. Western countries were also more likely to have higher body mass index, sedentary lifestyles and greater exposure to Western diets.
Study co-authors Dr Zeye Liu and Dr Yi Shi said: “Nowadays, more and more people are paying attention to the link between cancer and cardiovascular health.
“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.”
Dr Laxmi Mehta, chair of the American Heart Association’s Council on Clinical Cardiology, was not involved in the research.
She said: “Many of the same modifiable factors, including smoking, alcohol use, poor diet, physical inactivity and obesity, contribute to both breast cancer and cardiovascular disease including atrial fibrillation/flutter, as confirmed by this study’s findings.
“This overlap underscores the importance of integrated lifestyle strategies to reduce risk of cardiovascular disease and cancer. The American Heart Association’s Life’s Essential 8 highlights key behaviours and health factors essential for prevention and reducing risk.”
The researchers created global risk maps that could help healthcare professionals and policymakers develop prevention strategies tailored to different regions.
They plan to add long-term research and genetic, metabolic and socioeconomic data to future analyses.
The study used information from the Global Burden of Disease 2021 database.
Machine learning was used to examine global patterns, links between the two conditions and risk factors specific to different regions. Machine learning uses computer systems to identify patterns in large amounts of data.
The research was based on national-level information and did not include data about individual patients, meaning it cannot prove cause and effect.
Differences in screening, healthcare resources, data collection and definitions between countries may also have affected the results.
