The global spread of type 2 diabetes has increased dramatically in recent years and now affects millions of people worldwide. This number is expected to grow significantly in the future. A new study published in the British Medical Journal suggests a surprisingly simple choice – eating dark chocolate – may help lower your chances of the disease.
Researchers led by Binkai Liu and Qi Sun, Ph.D., of the Harvard T.H. Chan School of Public Health, working with teams in Shanghai and Boston, analyzed data from three large cohorts in the United States. These long-term studies collect data over many years and follow participants who did not have diabetes, heart disease or cancer at the time of enrollment.
The study examined how often participants ate chocolate, specifically dark and milk chocolate, and whether this affected their risk of developing type 2 diabetes. Those who regularly ate dark chocolate were significantly less likely to develop diabetes than those who rarely ate dark chocolate. However, eating milk chocolate did not show the same benefits. Dr. Sun explained: “This study is further evidence that what we eat can have a significant impact on our long-term health.”
Scientists believe that dark chocolate’s health benefits come from its rich content of natural compounds called flavanols. These substances are phytonutrients with powerful antioxidant and anti-inflammatory effects, meaning they protect cells from damage and reduce swelling. This can help protect your heart and improve how your body processes sugar. Studies have also found that regular consumption of dark chocolate is associated with a progressively lower risk of developing type 2 diabetes.
Milk chocolate, on the other hand, has been linked to weight gain, a major factor in diabetes. This highlights the importance of choosing the right type of chocolate for its health benefits. “Our findings suggest that not all chocolate is created equal – unlike milk chocolate, dark chocolate appears to have unique advantages,” Liu said.
The study used reliable methods, such as surveys that tracked participants’ diet and additional steps to confirm cases of diabetes. Surveys in this case involve participants regularly reporting what they eat, which helps researchers understand patterns over time. However, the researchers noted some limitations, such as the inability of such studies to prove cause and effect. They called for more in-depth research to confirm their findings and understand how dark chocolate may prevent diabetes.
The findings raise hope that simple dietary changes can have a real impact on preventing type 2 diabetes. “Understanding how common foods like chocolate affect chronic disease can help people make better food choices,” Sun said. As well as their role in preventing diabetes, the study highlights the wider health potential of foods rich in beneficial compounds such as flavanols, which are also found in fruits, vegetables and teas.
Journal reference
Liu Binkai, Zong Geng, Zhu Lu, Hu Yang, JoAnn E Manson, Wang Molin, Eric B Rimm, Frank B Hu, Sun Qi. “Chocolate intake and risk of type 2 diabetes: a prospective cohort study.” British Medical Journal. 2024;387:e078386. DOI: https://doi.org/10.1136/bmj-2023-078386
About the author
Dr. Sun Qi Renowned expert in nutrition and epidemiology at the Harvard T.H. Chan School of Public Health. His research focuses on the effects of diet and lifestyle on cardiometabolic health, including diabetes and cardiovascular disease. Dr. Sun has authored numerous influential studies, developed public health guidelines and promoted evidence-based nutrition. His work highlights the importance of simple, easy-to-implement dietary choices to prevent chronic disease and improve quality of life.
Liu Binkai is a professional researcher in the fields of nutrition and public health. Working closely with leading experts, Liu has contributed to large-scale studies exploring the link between diet and chronic disease. Liu’s work focuses on epidemiological research with an emphasis on identifying practical dietary interventions to improve global health outcomes. Liu has collaborated on several projects that highlight the role of specific foods, such as chocolate, in preventing diseases such as type 2 diabetes.
