Your habits in relation to exercise, diet, sleep and smoking impact your physical and mental health. We don’t always think about the second of these (mental health). But increasingly the research is showing that lifestyle choices influence mental health outcomes. This post discusses a fairly recent paper on the topic. Reading time ~ 5 minutes.
Many of you will be aware that lifestyle factors play a role in preventing and treating illness. What you eat, how much exercise you get, the quality of your sleep and the extent of drug/alcohol use all influence your risk for different illnesses and how well you manage existing illness.
When you are younger and in good health, you don’t necessarily spend much time thinking about the role of lifestyle factors in health, because your body recovers quickly, and you can more easily shrug off bad choices.
But if you are older or have experience with illness or injury, you tend to be more aware of the negative (and positive) impacts that one’s lifestyle choices have on health and wellbeing. For example, at my ripe old age I can feel the impact of my choices much more than when I was younger. They also show up on the blood tests that my doctor does (doh!).
The other thing I’ve noticed is that when health professionals discuss lifestyle factors, it is often in the context of physical illnesses and chronic diseases (e.g. cancer, musculoskeletal disorders, cardiovascular disease, lung disease, dementia), often conditions that affect people later in life and therefore less salient to someone in their youth.
But it isn’t just the health of our bodies that is affected by lifestyle choices, it is the health of our minds. We now recognise that lifestyle factors play a direct role in the emergence and trajectory of mental illnesses like depression, anxiety, bipolar and schizophrenia. Mental ill health and mental illness are much more relevant to young people given that youth is a peak age range for the emergence and impact of these conditions. Not surprisingly therefore, young people consistently rate mental health in their top 5 concerns.
Mental health clinicians have been aware of this connection between lifestyle factors and mental ill health for a while. Individuals struggling with mental illness often report poorer sleep, poorer diet, lower levels of physical activity and they are more likely to smoke or use drugs/alcohol. But it was often thought that the poor lifestyle choices were an outcome of mental ill health, emerging from the illness, rather than causing it. There wasn’t solid body of evidence to support a causal role in the opposite direction. That seems to be changing.
I spent some time recently reading a meta-review by Firth et al titled “A meta-review of ‘lifestyle psychiatry’: the role of exercise, smoking, diet and sleep in the prevention and treatment of mental disorders”. They wanted to know how lifestyle factors like exercise, smoking, diet and sleep influence the development of different mental disorders. They were interested in both prevention and treatment, that is, do lifestyle factors predict the emergence of mental illness AND can lifestyle factors be used to treat mental illness. Essentially, do lifestyle factors play a causal role in the development and trajectory of mental illness.
To test this, they reviewed and explored studies that had methodologies that could more confidently assess this type of causality. This included prospective studies that followed people over time, measuring them over multiple occasions, Mendelian randomisation studies that use genetic markers as a kind of randomised allocation, and Randomised Controlled Trials (RCT) that tested lifestyle interventions. They also limited themselves to meta-analyses, so they could be confident that the trends they were seeing reflecting patterns established over multiple observations.
What they found is:
Physical activity is the most widely researched protective factor for mental illness (i.e. increased physical activity reduces risk of mental illness) and its inclusion alongside traditional treatments may enhance treatment outcomes. For example, exercise adds additional benefit to the traditional treatment of depression via therapy and/or medication. Increases in physical activity are best achieved through supervised structured exercise interventions and/or public health efforts to change health environments. To date, the focus has mostly been on aerobic exercise (e.g. walking, running, cycling, swimming) but there is emerging evidence of the important of strength training 🏋🏽♀️
Poor sleep was the next most important lifestyle factor with poor sleep found to be a risk factor for both the emergence and aggravation of mental illness. Encouragingly, effective interventions for sleep disorders like insomnia such as CBTi are built on the same theory as treatments for anxiety and depression, so there is the potential to treat sleep and some mental disorders at the same time.
Smoking has increasingly been identified as a causal factor in the onset of depression, bipolar and schizophrenia (Note: it was originally assumed that this only worked in the other direction, that is, ill people smoked more). Interestingly, contrary to expectations, reducing tobacco use in those with mental ill health doesn’t worsen the condition, quite the opposite – it provides additional therapeutic benefit, along with already established risk reduction of physical illness that comes with smoking cessation.
Finally, the causal effects of diet on mental health are less clear. Reliable associations between diet and mental illness symptoms have been found, but that hasn’t yet translated into interventions that consistently change mental ill health outcomes through diet. But some recent trials are promising, where improvements in clinical depression have been achieved from Mediterranean diet interventions. This is an area to watch closely and one which I find personally fascinating.
What we’re seeing in this research is a convergence of body/mind health findings. What is good for the body is good for the mind (and vice versa). This opens up additional channels for healing and illness prevention. It gives individuals additional tools for positively influencing their mental health outcomes.
What does this mean for me as an individual?
Healthy lifestyle choices when we are younger don’t seem as important because the negative impacts previously described are typically conditions that emerge later in life.
However, mental health is a highly important topic for young people and the evidence increasingly shows lifestyle factors influence mental health outcomes. Thus, your choices in terms of physical activity, sleep, diet and smoking may have a more immediate impact than you’ve previously considered. If you’ve been ignoring these lifestyle areas, does this literature change how important you think it is?
If you’ve struggled with mental ill health, this literature provides hope, namely that attention to lifestyle factors may provide additional benefit on top of the existing medication or therapy options you are currently using. We know that existing treatments for mental illness don’t work for everyone, all of the time. Having more therapeutic avenues is a good thing – additional pathways for healing and management.
In terms of some simple starting points for taking action on these areas:
Physical activity – explore what Flinders Sports and Fitness have to offer.
Sleep – Start with implementing some simple sleep hygiene strategies and then reading further to learn more about sleep.
Smoking – Check out the Government’s guide to quitting smoking.
Diet – Familiarise yourself with the Australian Dietary Guidelines and the various tools/resources available to improve one’s nutrition.
What does this mean for us as a community?
We live in a culture that emphasises individual rights and responsibilities. Thus, it is seen as the responsibility of the individual to make good healthy lifestyle choices.
But we need to recognise that locating responsibility for lifestyle choices entirely in the individual is neither helpful, nor evidence-based. Yes, our individual decisions and choices matter, but those choices and decisions are influenced by our environment. If all campus food options are unhealthy, then people will make more unhealthy choices.
We need to consider whether our environments, processes, procedures and systems help individuals make healthy choices, without heavy-handed restriction of personal rights. This is a hard balance to achieve. Thus, I’d be interested to hear from readers what changes they’d like to see at Flinders, which would help them make better lifestyle choices. How could we as a community support each other to be healthier?
As a starting point, think about your own life and where you hang out. Do the places you hang out inspire you to make good choices? What changes could help? As a really simple example, I know that if I stock my home with healthy food and minimal unhealthy food, then I will make better choices more often. I’m not perfect by any means. My breakfast today was chocolate. But I also know that I will consume good food today because I have it at home: tea, veggies, fruit, nuts, whole grains. Modify the environment, modify the behaviour.
I hope you enjoyed this brief discussion of recent research. I’ll try to do more of these this year as I find interesting studies.