A longitudinal investigation conducted in the U.S. revealed a notable correlation between the regular consumption of at least five portions of dark chocolate weekly (defined as a standard bar/pack or 1 ounce) and a diminished susceptibility to type 2 diabetes, in contrast to infrequent intake. Conversely, augmented consumption of milk chocolate was linked to an escalation in body weight.
Opting for dark chocolate over milk chocolate might correlate with a reduced incidence of type 2 diabetes. Image courtesy of Sci.News.
The global incidence of type 2 diabetes has experienced a significant surge over the preceding decades, with approximately 463 million individuals affected worldwide in 2019, a figure anticipated to climb to 700 million by 2045.
Type 2 diabetes is a complex ailment stemming from multiple factors, characterized by insulin resistance and compromised insulin secretion, which can precipitate a cascade of serious health complications, including cardiovascular ailments, renal impairment, and visual deficits.
An expanding body of scientific inquiry has underscored the critical role of lifestyle determinants, such as healthful dietary practices, in the proactive management and prevention of type 2 diabetes.
A greater intake of total dietary flavonoids, as well as specific flavonoid subgroups, has been observed to correlate with a decreased risk of developing type 2 diabetes.
Within the context of randomized controlled trials, these flavonoids have demonstrated antioxidant, anti-inflammatory, and vasodilatory properties that may contribute to cardiometabolic well-being and mitigate the risk of type 2 diabetes, although the evidence has not been uniformly conclusive.
Chocolate, a product derived from the seeds of the cacao plant (Theobroma cacao), ranks among foods with the highest flavanol content and enjoys widespread popularity as a confectionary item.
Nonetheless, the relationship between chocolate consumption patterns and the likelihood of developing type 2 diabetes remains a subject of debate due to divergent findings in observational research.
For this latest investigation, Binkai Liu, affiliated with the Harvard T.H. Chan School of Public Health, alongside his colleagues, amalgamated data from three extensive U.S. observational cohorts comprising female nurses and male healthcare professionals who had no pre-existing conditions of diabetes, heart disease, or cancer at the commencement of their participation.
By employing food frequency questionnaires administered every four years, the researchers scrutinized the associations between type 2 diabetes and overall chocolate consumption among 192,208 participants. Furthermore, they examined the link between chocolate subtype (dark and milk) consumption and type 2 diabetes risk for 111,654 participants, spanning an average follow-up period of 25 years.
Given that alterations in body weight are strong predictors of type 2 diabetes risk, these same dietary questionnaires were utilized to ascertain participants’ total caloric intake.
In the analyses pertaining to total chocolate consumption, 18,862 individuals were diagnosed with type 2 diabetes. Following adjustments for individual, lifestyle, and dietary risk factors, the study authors determined that individuals consuming at least five servings per week of any chocolate variety exhibited a statistically significant 10% lower incidence of type 2 diabetes compared to those who rarely or never consumed chocolate.
In stratified analyses by chocolate subtypes, 4,771 diagnoses of type 2 diabetes were recorded. After controlling for the identical set of risk factors, individuals who consumed at least five servings weekly of dark chocolate demonstrated a statistically significant 21% reduction in their risk of developing type 2 diabetes. However, no statistically significant associations were identified concerning milk chocolate intake.
The research team also identified a 3% decrease in the risk of type 2 diabetes for each supplementary weekly serving of dark chocolate, indicating a dose-response relationship.
An increase in the consumption of milk chocolate, but not dark chocolate, was correlated with long-term weight gain.
While dark chocolate and milk chocolate possess comparable caloric and saturated fat profiles, the elevated flavanol content in dark chocolate may serve to counterbalance the adverse metabolic effects of saturated fat and sugar on weight management and the predisposition to other cardiometabolic conditions, such as diabetes.
“The augmented intake of dark chocolate, as opposed to milk chocolate, was found to be associated with a diminished risk of type 2 diabetes,” stated the researchers.
“Conversely, increased consumption of milk chocolate, but not dark chocolate, was linked to sustained weight gain.”
“Further rigorous randomized controlled trials are imperative to corroborate these findings and to elucidate the underlying mechanisms more comprehensively.”
The study was officially published this week in the esteemed journal, The BMJ.
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Binkai Liu et al. 2024. Chocolate intake and risk of type 2 diabetes: prospective cohort studies. BMJ 387: e078386; doi: 10.1136/bmj-2023-078386
