Dietary inflammatory index and recurrence of depressive symptoms: Results from the Whitehall II Study

Abstract

There is a growing interest in understanding the role of inflammation in diet-depression relationship. The present study examined whether the dietary inflammatory index (DII, a measure of the inflammatory potential of individuals' diets) is associated with recurrent depressive symptoms (DepS) (CES-D score>16 or taking antidepressants both at baseline and follow-up) assessed over 5 years in middle-aged men (n=3178) and women (n=1068) from the Whitehall II Study. For each increment of 1 SD of DII score, odds of recurrent DepS increased by 66% (95 % CI:1.30-2.12) in women while no significant association between DII and recurrent DepS was observed in men (OR=1.12, 95 % CI: 0.92-1.36). This association was little attenuated after adjustment for confounders and after taking into account levels of interleukin-6 and C-reactive protein. In conclusion, there is an association between pro-inflammatory diet and recurrent DepS in women which seems not be driven by circulating inflammatory markers.

Figure 1

Flow chart diagram mapping the selection of participants

Figure 2

Association between dietary inflammatory Index score and recurrent depressive symptoms over 5 years in 3178 men and 1068 women from Whitehall II study DII was categorized in tertiles, median and range were for Tertile 1 : −1.30 (−3.35; −0.68), Tertile 2 : −0.19 (−0.68; 0.43) and for Tertile 3 : 1.35 (0.43; 4.23). Proportions of men and women in each tertile were : 33.5% of men and 32.7% of women in Tertile 1, 33.6% of men and 32.7% of women in Tertile 2, and 32.9% of men and 34.6% of women in Tertile 3. Model 1 : adjusted for age, ethnicity, and total energy intake. Model 2 : Model 1 + socio-economic status, marital status, smoking habits, physical activity, and alcohol intake. Model 3 : Model 2 + coronary heart diseases, type 2 diabetes, hypertension, HDL-cholesterol, use of lipid-lowering drugs, central obesity, and cognitive impairment.