The global spread of type 2 diabetes has increased dramatically in recent years, now impacting millions of people worldwide. This number is expected to grow significantly in the future. A new study published in The BMJ suggests that a surprisingly simple choice—eating dark chocolate—could help lower the chances of developing this condition.
Researchers, led by Binkai Liu and Dr.Qi Sun from Harvard T.H. Chan School of Public Health, worked with teams in Shanghai and Boston to analyze data from three large groups in the United States. These long-term studies, which gather data over many years, followed participants who did not have diabetes, heart disease, or cancer when they enrolled.
The study examined how often participants ate chocolate—specifically dark and milk varieties—and whether this affected their risk of type 2 diabetes. Those who ate dark chocolate frequently were significantly less likely to develop diabetes than those who rarely consumed it. However, eating milk chocolate did not show the same benefit. “This study adds to growing evidence that what we eat can have a big impact on our long-term health,” explained Dr. Sun.
Scientists believe that dark chocolate’s health benefits come from its rich content of natural compounds called flavanols. These substances, which are plant-based nutrients, have powerful antioxidant and anti-inflammatory effects, meaning they can protect cells from damage and reduce swelling. This can help protect the heart and improve how the body processes sugar. The study also found that regularly eating dark chocolate was linked to gradual decreases in the risk of developing type 2 diabetes.
On the other hand, milk chocolate was associated with weight gain, which is a major factor in the development of diabetes. This highlights the importance of choosing the right type of chocolate for health benefits. “Our results suggest that not all chocolate is the same—dark chocolate appears to offer unique advantages, unlike its milk counterpart,” said Liu.
The study used reliable methods, such as surveys to track participants’ diets and additional steps to confirm cases of diabetes. Surveys in this context involve participants regularly reporting what they eat, which helps researchers understand patterns over time. However, the researchers noted some limitations, like the fact that this type of research cannot prove cause and effect. They called for more in-depth studies to confirm their findings and understand how dark chocolate might protect against diabetes.
This discovery offers hope for simple dietary changes that could make a real difference in preventing type 2 diabetes. “Learning how common foods like chocolate influence chronic conditions can help people make better food choices,” Qi Sun said. Beyond its role in diabetes prevention, this research highlights the broader health potential of foods rich in beneficial compounds like flavanols, which are also found in fruits, vegetables, and tea.
Journal Reference
Binkai Liu, Geng Zong, Lu Zhu, Yang Hu, JoAnn E Manson, Molin Wang, Eric B Rimm, Frank B Hu, Qi Sun. “Chocolate intake and risk of type 2 diabetes: prospective cohort studies.” The BMJ. 2024;387:e078386. DOI: https://doi.org/10.1136/bmj-2023-078386
About the Authors
Dr. Qi Sun is a 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, shaping public health guidelines and promoting evidence-based nutrition. His work emphasizes the importance of simple, accessible dietary choices in preventing chronic illnesses and improving quality of life.
Binkai Liu is a dedicated researcher in the field of nutrition and public health. Working closely with leading experts, Liu has contributed to large-scale studies exploring the connections between diet and chronic diseases. With a focus on epidemiological research, Liu’s work emphasizes identifying practical dietary interventions to improve global health outcomes. Liu has collaborated on multiple projects that highlight the role of specific foods, like chocolate, in preventing conditions such as type 2 diabetes.
