There is an increasing body of evidence to demonstrate that what we eat can directly affect our mood. It is more than just that feeling of guilt you might experience after digging into a pizza or burger and fries, but rather a measurable change in the neurotransmitters responsible for your mood.
Often called the “happy hormones”, serotonin and dopamine are two key signals to the brain that regulate mood. We know that your gut contains 90% of the body’s serotonin receptors (hence the reason that many antidepressants have gut side-effects), and that these receptors are directly activated by the gut’s bacteria. The balance of these bacteria is known to be altered by the quality of one’s diet, and in simple terms healthier diets (e.g. wholefood, plant-based or Mediterranean) are associated with “happier” mood signals. The gut communicates directly with the brain via the vagus nerve – the very same one that is responsible for the relaxation response (a bit of a clue!). Studies now show that healthier diets may be protective against depression and in fact could even be used as a treatment for the condition.
Ultra-processed and other refined foods on the other hand, negatively impact the bacterial balance in the gut, and therefore the signals sent to the mood centre of the brain, potentially directly exacerbating depressive symptoms.
But what about the link between lifestyle and mood in MS? Well we know that up to 50% of people with MS (pwMS) will suffer from a depressive episode at some point (twice that of the general population risk), often due to a combination of the many life-altering effects of living with MS, but also due to MS related damage to parts of the brain that control mood.
Data from Prof. Jelinek’s HOLISM Study has previously shown that those exercising regularly, eating more fish, taking vitamin D and supplementing with plant-based omega-3 have a significantly lower incidence of depression than those leading less healthy lifestyles.
So if we know all of this already, why bring it up again?!
Well, increasing the evidence-base behind our recommendations is a key principle of OMS, and a new Australian paper has done just that. Published in “Acta Neurologica Scandinavica”, this is a collaboration between researchers from the University of Melbourne and MS Research Australia, assessing if modifiable lifestyle factors influence MS symptoms.
1500 pwMS completed a survey regarding their lifestyle; assessing smoking, nutrition, alcohol intake and levels of physical activity – using the SNAP Scoring System, a well-established method of assessing lifestyle. The participants also completed a survey on their symptoms of anxiety and depression, using the Hospital Anxiety and Depression Scale (HADS) – allowing for direct comparisons between lifestyle and mood.
They found further evidence that depression and anxiety are very common in pwMS, present in 27% and 40% of participants respectively, with 20% experiencing both symptoms. Only 3% met all the healthy lifestyle recommendations of SNAP, and only 10% reported adequate fruit/vegetable intake (defined as eating five or more servings of vegetables a day, or two or more servings of fruit at least six days a week). 22% reported a combination of unhealthy weight, inadequate physical activity and inadequate nutrition. Cigarette smoking and consumption of more than two standard alcoholic drinks daily were also associated with an increased risk of depression.
A healthier SNAP score was clearly associated with a lower prevalence and severity of depression, but not anxiety (which the researchers felt may have been due to the way that anxiety disorders are classified in the HADS). For each additional healthy behaviour there was a directly proportional reduction in depression scores.
Like the wider population, this study indicates that most people with MS are not reaching the minimum recommendations for a healthy lifestyle, but that for those leading a healthier lifestyle they are significantly less likely to develop depression, and those that do tend to have less severe symptoms. The researchers would now like to investigate whether changing lifestyle can be used to treat depression and anxiety in pwMS.
Given that the OMS program advocates a lifestyle that would be considered healthy by almost any standards, this new evidence should provide more reassurance regarding its benefits, and hopefully is enough to put a small smile on the faces of OMSers everywhere.