Danish researchers link chocolate consumption and atrial fibrillation.
Few people can resist chocolate. That’s why a paper from US, Canadian, and Danish scientists in Heart, from the British Medical Journal group, was hailed as good news. The study showed that regularly eating chocolate might reduce risk of atrial fibrillation (AF), which is an irregular heartbeat. Professor Kim Overvad, Departments of Public Health, Aarhus University, and Aalborg University Hospital, was the paper’s senior author. “Our main research focus,” he says, “is a better understanding about diet and the development of chronic diseases.”
In their research to find links between dietary components and risk of diabetes, cancer, heart disease and other conditions, Overvad and colleagues analyze prospectively collected clinical, physiological, and lifestyle data on large cohorts from the general population. For the chocolate study, data was from the Danish Diet, Cancer, and Health study, with more than 57,000 participants. On entering the cohort in the 1990s, participants were aged 50–64 years. They had baseline lab tests, gave adipose tissue samples, and provided information on factors such as education and smoking. Eating habits were collected with a food-frequency questionnaire. Diagnoses and other medical information are from the Danish National Patient Register.
A chocolate-AF link
AF increases risk of stroke, dementia and other diseases and affects nearly 9 million in Europe. Multiple studies show that eating chocolate may reduce heart disease risk but data on chocolate and AF were contradictory. Therefore, Overvad’s group looked at data over 13.5 years, including on 3346 people diagnosed with AF. They found that regular chocolate intake was associated with 11–20% lower occurrence of diagnosed AF in men and women, compared to people who ate less than one 30-gram serving of chocolate a month. The link held when findings were adjusted for factors such as age, smoking, and other heart conditions. Dark chocolate could be a healthy snack, the researchers concluded. Compounds in chocolate might reduce oxidation and inflammation, which contribute to heart disease including AF.
The long view on diet news
Overvad’s research group is also using large datasets to study how major dietary components such as meat and dairy, vegetables, and starches influence weight and disease development. Since this work touches on a central part of our lives—food—it is often in the news.
Don’t focus too much on every new diet report, Overvad advises. “Each study,” he says, “just adds a small piece to the larger puzzle of understanding our diet and health.” The goals of nutritional epidemiologists are broad, he says: “We look at the research results as a whole, to learn about a balanced diet that we can all live with in the long term.”
Mostofsky E, Johansen MB, Tjønneland A, Chahal HS, Mittleman MA, Overvad K. Chocolate intake and risk of clinically apparent atrial fibrillation: the Danish Diet, Cancer, and Health Study. Heart, 2017 DOI: 10.1136/heartjnl-2016-310357