Diet and mental health is an emerging area of research which aims to prove if certain food-based lifestyle changes can significantly improve quality of life for those living with a mental illness. In this blog we will begin to explore the Mediterranean diet’s role in improving depressive symptoms and general mood as well as some convenient tips for incorporating this evidence into everyday practice.    

The ‘SMILES’ trial

This study was one of the first randomized control trials (RCTs) investigating whether diet can be used alongside standard treatment methods to improve depressive symptoms and mood.¹ Focusing on adults with moderate to severe clinical depression, the Mediterranean diet and one-on-one consultations from a clinical dietitian were given to participants on top of their typical treatment regimes, which was compared against participants receiving standard treatment and equal amount of social support over 3 months.² When compared from baseline, this study revealed far greater improvements in depressive symptoms and mood for those allocated to the Mediterranean diet group than those allocated to the social support group. Additionally, only 8% of those receiving standard treatment with social support achieved clinical remission compared to 32.3% of the Mediterranean Diet group.² Whilst this trial is a preliminary investigation, the results suggest that improving diet quality can positively support mental health recovery when guided by a clinical dietitian.²

The HELFIMED study

This study also investigated whether the Mediterranean Diet is a more effective adjunctive treatment method than social support groups.³ This time the intervention group took part in fortnightly group cooking classes focusing on the key evidence-based principles of the Mediterranean Diet to create simple, affordable and tasty meals.³ In contrast to the SMILES trial, the group cooking classes gave the Mediterranean Diet participants the chance to form friendships within the study and benefit further from peer support just like they would have in the social support group.³ During the first 3 months of the study, those participating in the cooking classes saw a far more significant improvement in quality of life and a 45% improvement in the Depression Anxiety Stress Scale, compared to a 26.8% improvement in the social group.³ From this study it can be concluded that improving diet quality can support mental illness recovery, with social cooking classes providing a fun and empowering method for dietary adherence.³  

Summary of Dietary Intervention

The dietary advice given in these two trials aligns with the key principles seen in most high quality Mediterranean Diet papers.^2,3 Each study emphasized the importance of eating plenty of vegetables, fruit, whole grains, legumes, seeds and nuts alongside oily fish and other lean cuts of meat.^2,3 Another main message was to ensure that extra virgin olive oil (EVOO) was the main source of fat participants were consuming.^2,3 In the SMILES trial participants were told to consume at least 3 tablespoons of EVOO per day,² whereas those in the HELFIMED trial were given 500ml bottles of EVOO in food hampers to maximise adherence to the trial advice.³ Together these two studies highlight the importance of cooking with EVOO over other fats, as EVOO naturally contains high amounts of anti-inflammatory compounds and monounsaturated fatty acids which contribute to the health benefits typically seen from implementing the Mediterranean Diet.^2,3

Incorporating the Evidence into Everyday Practice

Depending on a person’s current diet, making the shift to Mediterranean eating patterns can be quite a big change, especially when living with a mental illness. As a core ingredient of the Mediterranean diet, this is where EVOO shines! As it is a great oil for cooking and provides flavour when used as a dressing, incorporating more EVOO in the diet can serve as a great first step when teaching the key principles of the Mediterranean Diet, as this change can be easily adopted across a wide range of food literacy skills.  

Conclusion

Although the relationship between diet and mental health is relatively new, there are a number of high quality RCTs which support the use of the Mediterranean Diet as an adjunctive treatment method when supported by nutrition professionals. As not everyone who seeks dietary assistance with mental health management is ready to make big changes to their diet, making EVOO a more predominant source of fat in the diet may be the perfect place to start.  

Published 31/10/2024

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