Long-term increase in Mediterranean diet adherence combined with decrease in ultra-processed food consumption is...

Area of Science:

• Nutritional Psychiatry
• Longitudinal Cohort Studies
• Mental Health Research

Background:

• Mediterranean diet (MD) is linked to lower depression risk.
• High ultra-processed food (UPF) intake correlates with poorer mental health.
• Long-term combined effects of MD and UPF changes on depression are understudied.

Purpose of the Study:

• To investigate the relationship between joint trajectories of MD adherence and UPF consumption.
• To analyze how these dietary patterns influence changes in depressive symptoms over time.

Main Methods:

• Longitudinal analysis of 1417 adults from the Moli-sani Study (2005-2010).
• Dietary data assessed using Mediterranean Diet Score (MDS) and Nova system for UPFs.
• Depressive symptoms measured by Patient Health Questionnaire-2 (PHQ-2) over a median 12.7-year follow-up.

Main Results:

• Increased MD adherence and reduced UPF intake independently associated with slight PHQ-2 score reductions.
• The "increased MD/reduced UPF" group showed greater PHQ-2 score decrease compared to "reduced MD/increased UPF" group (β = -0.42).
• Stable MD adherence with reduced UPF, or increased MD with stable UPF, also led to reduced depressive symptoms.

Conclusions:

• Depressive symptoms decreased with reduced UPF intake, especially with stable MD adherence.
• MD adherence increase benefited mental health only if UPF intake did not rise.
• Combined dietary improvements, focusing on reducing UPFs and enhancing MD, are crucial for significant mental health benefits.