The relationship between the dietary inflammatory index (DII ®) and incident depressive symptoms: A longitudinal cohort study

J Affect Disord. 2018 Aug 1;235:39-44. doi: 10.1016/j.jad.2018.04.014. Epub 2018 Apr 4.


Background: Diet is a common source of inflammation, and inflammation is associated with depression. We examined the association between the dietary inflammatory index (DII®), a validated measure of inflammatory potential of the diet, and risk of depression in a cohort of older North American adults.

Methods: This longitudinal study, with a follow-up of 8 years, included 3648 participants (1577 males, 2071 females; mean age: 60.6 years) with/at risk of knee osteoarthritis. DII® scores were calculated using the validated Block Brief 2000 Food-Frequency Questionnaire. Center for Epidemiological Studies Depression-20 scale was used to define depressive symptoms. The relationship between baseline DII® score and incident depression was assessed through Cox's regression analysis, adjusted for potential confounders, and reported as hazard ratios (HRs).

Results: In total, 837 individuals (310 men and 527 women) developed incident depressive symptoms over the course of 8 years. Participants in the most pro-inflammatory group (quartile 4) had approximately 24% higher risk of developing depressive symptoms compared to subjects with the most anti-inflammatory diet (HR: 1.24; 95% CI: 1.01-1.53; p = 0.04).

Conclusion: These results suggest that a pro-inflammatory diet may be associated with higher incidence of depressive symptoms in a cohort of older Americans. Transitioning to a more anti-inflammatory diet may reduce depression risk.

Keywords: Depression; Health behavior; Neuroimmunology; Old age.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cohort Studies
  • Depression / epidemiology
  • Depression / etiology*
  • Diet / adverse effects*
  • Diet Surveys / statistics & numerical data*
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Inflammation / etiology
  • Inflammation / psychology*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Proportional Hazards Models
  • Psychiatric Status Rating Scales