Proinflammatory Diet May Lead to Long-Term Depression, Anxiety in MS

A proinflammatory diet is associated with the long-term development of depression and anxiety among patients with multiple sclerosis (MS), according to study findings published in the journal Multiple Sclerosis and Related Disorders.

Patients with MS experience high rates of depression, anxiety, and fatigue and these symptoms severely impact quality of life. Previous studies among the general population found that proinflammatory diets were associated with depression and anxiety.

To evaluate the role of a proinflammatory diet among patients with MS, researchers sourced data for this study from the Ausimmune and AusLong studies, which was a multicenter case-control study conducted in 4 regions in Australia starting in 2003 with a longitudinal component. Patients (N=190; 81% women) with MS were evaluated by the Dietary Inflammatory Index (DII^®), the energy-adjusted DII (E-DII), Hospital Anxiety (HADS-A) and Depression (HADS-D) Scales, and Fatigue Severity Scale (FSS) instruments at baseline and at 5- and 10-year follow-ups.

A total of 78% of patients were taking disease-modifying therapies (DMTs). At the 5- and 10-year follow-ups, the patients were mean age 44.5 and 48.65; had a body mass index (BMI) of 27.4 and 27.90 kg/m²; spent 1.8 and 1.66 days per week engaging in vigorous physical activity in the last 12 months; and their total energy intake was 7087.9 and 6570.81 kJ/day, respectively.

At the 5-year follow-up the average DII score was 1.58 (range, -2.90 to 4.021) and E-DII score was 0.55 (range, -3.30 to 4.22).

No association between DII and E-DII scores in the previous 12 months were observed with depression, anxiety, or fatigue outcomes.

However, DII (b, 0.66; P <.001) and E-DII (b, 0.47; P <.001) scores at baseline and year 5 were associated with depression scores at 5 and 10 years. Compared with individuals with a DII score of -2.176 to 0.241, those with a score of 1.865 to 2.682 (b, 1.81; P <.001) or >2.682 (b, 2.42; P <.001) had higher depression scores at follow-up.

Similarly, E-DII score of >1.834 associated with higher depression scores compared with scores of -3.150 to -5.710 (b, 2.23; P <.001).

Anxiety at follow-up was related with E-DII scores at baseline and 5-years (b, 0.39; P <.001), in which scores >1.834 were associated with higher anxiety scores (b, 1.90; P <.001) compared with scores of -3.150 to -5.710.

The effect of inflammation accumulation via diet throughout the study, defined as an E-DII cumulative score between -10.06 to 10.04, was associated with depression at the 10-year follow-up (b, 0.20; P =.01).

No interaction between DMT use and the effect of dietary inflammation on depression was observed (P >.13). However, a significant modification effect of DMT use on the association between DII scores and anxiety at 10 years was observed (P =.05).

This study may have been biased by some confounding factors that correlated with proinflammatory diet with depression and anxiety outcomes.

“If the relationship with depression and anxiety is causal, then the longer-term consumption of anti-inflammatory diets could be recommended to decrease depression and anxiety symptoms in people with MS,” the researchers concluded.

Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.