BACKGROUND AND PURPOSE:

• Consuming more dietary flavonoids has been linked to a decreased risk of type 2 diabetes (T2D)
  • Chocolate is one of the foods with the highest flavonoid content
  • The association between T2D and chocolate consumption has been obscured due to the failure to account for the type of chocolate (milk, dark, or white) consumed
• Liu et al. (BMJ, 2024) investigated the associations between dark, milk, and total chocolate consumption and risk of T2D in three US cohorts

METHODS:

• Prospective cohort studies
  • Nurses’ Health Study (1986 to 2018) | Nurses’ Health Study II (1991 to 2021) | Health Professionals Follow-up Study (1986 to 2020)
• Participants
  • Individuals without T2D, cardiovascular disease or cancer at baseline
• Exposures
  • Total chocolate intake | Intake by chocolate subtype
• Study design
  • Cox proportional hazards regression was used to estimate hazard ratios (HR)
  • Adjustments: Personal | Lifestyle | Dietary risk factors
• Primary outcome
  • Incidence T2D

RESULTS:

• 192,208 individuals included in total chocolate analysis | 11,654 individuals included in chocolate subtype analysis
  • 4,829,175 person years of follow-up
• Participants consuming ≥5 servings/week of any chocolate showed a significantly lower rate of T2D compared to those who never or rarely consumed chocolate
  • HR 0.90 (95% CI, 0.83 to 0.98) | P_trend=0.07
• Participants who consumed ≥5 servings/week of dark chocolate showed a significantly lower risk of T2D
  • HR 0.79 (95% CI, 0.66 to 0.95) | P_trend=0.006
• There was no significant association found for milk chocolate intake
  • HR 0.94 (95% CI, 0.79 to 1.12) | P_trend=0.75
• There was a linear dose-response association between dark chocolate intake and risk of T2D (P for linearity=0.003)
• Risk decreased by 3% per serving/week of dark chocolate consumption
  • HR 0.97 (95% CI, 0.95 to 0.99)
• Intake of milk chocolate was associated with increased weight gain
• Intake of dark chocolate was not associated with weight gain

CONCLUSION:

• Eating dark chocolate was associated with a lower risk of T2D
• Milk chocolate was not associated with a benefit, but was associated with greater weight gain
• The authors state

Intake of dark chocolate instead of milk chocolate may be associated with a lower risk of T2D

Further research, especially randomized controlled trials among middle aged participants and of longer duration, is needed to confirm these findings

Learn More – Primary Sources:

Chocolate intake and risk of type 2 diabetes: prospective cohort studies