Only one more visit to the gym each week can significantly reduce depression in South African women, a landmark study has found.
The findings of the study conducted by Discovery Vitality, with the assistance of researchers from the Harvard T.H. Chan School of Public Health and the University of Cape Town (UCT), was recently published in the International Journal of Physical Medicine and Rehabilitation and serves as global-first that focuses on an African data set.
“The research focused on the South African context and has produced novel findings, considering that prior research comes from high-income Western settings,” said Prof Dan Stein, chair of the Department of Psychiatry at UCT during a media roundtable discussion held in Cape Town on 14 October.
Exercise is paramount
The main findings indicated that women have almost double the incidence of depression compared to men, and that a small increase of physical activity like a 30 min low-impact exercise has shown a significant reduction of depression incidence in women, while no significant effect was noted for men.
“Our analysis indicated that increasing physical activity from low to moderate or from low to high, in the female population could prevent 19,3% and 16,3% cases of depression, respectively,” says Stein.
He says depression is on a spectrum that ranges from relatively low moods on the one end to waking up with such high anxiety levels and being too nervous to enter a room.
Also, women are more prone to depression than men, who are more prone to substance abuse. Although there is not one single explanation for this, Stein says many factors can play a role ranging from hormonal changes, the pressure of fulfilling multiple roles and society putting more pressure on women to succeed.
Brain power
“Physical health and mental health is interconnected and our findings are consistent with a growing understanding of neurobiology of exercise. Exercise releases thousands of molecules and something happens in the brain and in the blood. It is too complex to know exactly what exercise changes in the brain, but it does. Physical activity changes the brain-derived neurotrophic factor gene (BDNF) in the brain that protects the nervous system,” he says.
Vitality’s head of wellness Dr Mosima Mabunda says depression is prevalent and increasing globally.
Pre-pandemic, 970 million people were living with mental disorders worldwide – 13% of the global population estimated in 2019.
“Of this, 280 million people have depression. Either you or someone you know have depression. It is a debilitating disease and at its worse can lead to suicide. Over 700 000 people die due to suicide every year across the globe,” she says.
“As the Covid-19 pandemic was a stressful time due to isolation, job loss and fear of infection, major depressive disorders increased by 28% and anxiety by 26%.”
Exercise promotes neuroplasticity
Clinical psychologist Dr Colinda Linde says exercise allows for neuroplasticity in the brain and that as little as 20 minutes a day can protect your brain.
“Brain health protects you not only from depression and anxiety but also things like dementia and brain fog. Exercise promotes neuroplasticity which is the forming of new neural connections in the brain allowing change, as well as the health of the organ,” says Linde.
The three-year study used health and physical activity data of 49 397 unique individuals between the period of 2013 to 2015, collected by Discovery Vitality and Discovery Health Medical scheme. Participants were categorised by change in physical activity level after three years and depression incidence was compared among these cohorts.
The analysis also tested for sex by cohort interaction and conducted stratified analysis by sex.
