A large-scale study from the University of Exeter has found ‘robust evidence’ that being overweight hikes up your risk of developing depression – but as fresh evidence confirms, logging your morning miles is one of the most effective ways to fight back. Exercise jolts your brain into action, and not just because of the endorphin high, according to findings from Ruhr-Universität Bochum.
Let’s take a look at the first study. The University of Exeter team examined data from more than 145,000 participants, honing in on two key genetic variants to determine whether the heightened risk of depression is caused by ‘psychosocial pathways’, such as social stigma and societal expectations, or ‘physical pathways’ like high blood pressure, diabetes and heart disease.
There was little difference between the two sets of genes, the scientists discovered – indicating that a mix of metabolic and psychological factors are behind the higher rates of depression seen in people with a high BMI, or body mass index (if you need a reminder, BMI is a measure of body fat based on a formula involving your height and weight).
‘Obesity and depression are both major global health challenges, and our study provides the most robust evidence to date that higher BMI causes depression,’ said lead author Jess O'Loughlin. ‘Understanding whether physical or social factors are responsible for this relationship can help inform effective strategies to improve mental health and wellbeing.
‘Our research suggests that being fatter leads to a higher risk of depression, regardless of the role of metabolic health,’ she continues. ‘This suggests that both physical health and social factors, such as social stigma, both play a role in the relationship between obesity and depression.’
To stave off the Black Dog, start by lacing up. Exercise combats depression with a one-two punch, the Ruhr-Universität Bochum team found: not only does it neutralise symptoms, but it also increases the brain’s ability to change, known as neuroplasticity. This ability, described as ‘the root of human experiences’, is known to be stunted by depression.
For the study, they enlisted 41 people undergoing treatment for depression and assigned half of them to a three-week exercise programme developed by the sports science team from the University of Bielefeld (the other group acted as a control). The scientists established the severity of participants’ depressive symptoms both before and after the programme and recorded neuroplasticity using transcranial magnetic stimulation.
At the end of the three weeks, depressive symptoms decreased among participants who completed the exercise programme, while neuroplasticity ‘increased significantly’. ‘The results show how important seemingly simple things like physical activity are in treating and preventing illnesses such as depression,’ says study leader associate professor Dr. Karin Rosenkranz.
