What foods do you reach for as a coping mechanism for emotions like stress or anxiety? Most of us are tempted by the instant gratification of sweet, salty or fatty foods. But eating these foods can exacerbate the unpleasant emotions you are trying to escape.
‘Food and mood’ has been a buzz phrase in the nutrition space in recent years, with strong supporting evidence that your foundation diet (what you eat most of the time) is important for your mental health.
Two recent Australian clinical trials found a positive correlation between the Mediterranean diet and reduced depression [1, 2], reporting the diet intervention to be more effective than social support counselling.
A Mediterranean foundation diet includes a plentiful consumption of vegetables, fruit and wholegrains; moderate amounts of fish, legumes, nuts, dairy; and small amounts of lean meat. Extra virgin olive oil is the main source of fat (3 – 4 tablespoons per day), in place of butter or other oils. The diet’s foods are also minimally processed, which means they are close to their natural state or have only a few ingredients.
One major factor in the link between Mediterranean diet and reduced depressive symptoms is its anti-inflammatory effect. This is important for depression and anxiety because ongoing inflammation can predict depressive symptoms.
The wholesome foods in the Mediterranean diet are rich in antioxidants and healthy fats including omega-3, which help lower inflammation [3, 4]. In turn, the diet lacks highly processed foods that are high in added sugar or saturated fat, such as cakes, softdrinks and fried foods, which cause an increase in inflammation.
The latest national health survey found that less than five percent of Australian adults eat the recommended two serves of fruit and five serves of vegetables per day, and 35 percent of their daily calories come from treat foods . These staggering statistics indicate most of us can benefit from adopting principles of a Mediterranean diet.
The Mediterranean diet’s anti-inflammatory effects are also achieved through supporting a healthy gut microbiome with a high diversity of bacteria . Probiotic foods, such as natural yoghurt, increase the number of certain bacteria in our gut, but to keep them alive and happy we need to feed them prebiotic foods which are plant foods. Plant foods help our gut bacteria produce short-chain fatty acids, which plays an important role in lowering systematic inflammation.
It is recommended to aim for 30 different plant foods per week for a healthy gut diversity, including nuts, seeds, fruit, vegetables, legumes and pulses, bread, rice and oats. For example, rye toast with egg, sautéed spinach, tomato and avocado gives you a tally of four. Another gut-loving food choice is cooked and cooled rice, potato and pasta which contain starch. The cook-cooling process alters the structural formation and it becomes ‘resistant starch’ – a feast for your gut bugs.
In conclusion, your food choices influence your mood. In your everyday diet, choose minimally processed foods and include plenty of plant foods to optimise your gut microbiome – the greater the variety the better! We should consider diet and lifestyle as a foundation of our mental health. If you would like individualised advice on optimising your diet be sure to consult a dietitian.
ABOUT THE AUTHOR: Annelise Jefferies is an Accredited Practicing Dietician with a keen interest in clinical research and translating latest research findings into practice. She works at USC’s Thompson Institute on its future Healthy Brain Ageing Clinic program, which will research the combination of lifestyle interventions known to reduce dementia risk. The Mediterranean Diet is one of those interventions.
1. Jacka, F., et al., A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES trial). BMC Medicine, 2017. 15(1).
2. Firth, J., et al., The Effects of Dietary Improvement on Symptoms of Depression and Anxiety: A Meta-Analysis of Randomized Controlled Trials. Psychosomatic medicine, 2019. 81(3): p. 265.
3. Mayr, H.L., et al., Improvement in dietary inflammatory index score after 6-month dietary intervention is associated with reduction in interleukin-6 in patients with coronary heart disease: The AUSMED heart trial. Nutrition Research, 2018. 55: p. 108-121.
4. Ruiz-Canela, M., et al., Dietary inflammatory index and anthropometric measures of obesity in a population sample at high cardiovascular risk from the PREDIMED (PREvención con DIeta MEDiterránea) trial. British Journal of Nutrition, 2015. 113(6): p. 984-995.
5. Zalli, A., et al., Low-grade inflammation predicts persistence of depressive symptoms. Psychopharmacology, 2016. 233(9): p. 1669.
6. Australian Bureau of Statistics. Australian Health Survey: Consumption of food groups from the Australian Dietary Guidelines. 2016.
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