If you surveyed people walking down a street, I bet you the super majority of them would respond “yes” when asked if exercise is good for you. Most of us understand that exercise is good for general health and can reduce the risk of some diseases.
But what does moving your muscles and getting your blood pumping have to do with the brain? And multiple sclerosis?
I want to pause for a beat and recognise that I know exercise is challenging. It’s challenging for anyone to get to the gym and commit to a workout. But for those living with MS, fatigue and other physical effects of multiple sclerosis make it even more challenging. So I don’t want this post to come off like I am forgetting this important reality. However, as a scientist, I want to share my thoughts on exercise from the scientific perspective.
It is well-known that exercise can protect nerve cells and that it promotes improvements in memory in mice in a laboratory setting. Indeed, using experimental autoimmune encephalomyelitis (EAE), a widely used animal model of human MS, researchers have shown that exercising mice on a running wheel can reduce neurological deficits. Good news, but what about for people living with MS?
Recent research has investigated the impact of aerobic exercise on learning and memory in people living with MS, demonstrating that aerobic exercise can improve memory with a simultaneous increase in the volume of the hippocampus, an important region of the brain associated with learning and memory. In addition, human trials have indicated that different exercise interventions may improve quality of life, muscle strength, walking ability and even fatigue. Recently, a beneficial effect of exercise training in people living with progressive forms of MS has been observed in terms of aerobic fitness, walking ability, cognitive function and neuropsychiatric symptoms.
But why is this happening?
There is a body of research evidence indicating that exercise training can dampen down damaging inflammatory events in our bodies that impact our nervous and immune systems in a negative manner. More specifically, I previously wrote about cytokines, a family of proteins that orchestrate immune responses and direct the movement of cells towards sites of damage, infection and inflammation. For people living with MS, research indicates that exercise significantly reduces the production of key inflammatory cytokines in the blood of patients, which may protect the body against inflammation. These findings are supported by research in other labs indicating that exercise can enhance the blood levels of the neurotrophin, brain-derived neurotrophic factor (BDNF). As I also discussed in a previous article, this neurotrophin is produced by both nerve and immune cells, and is central in health and disease as it promotes the survival of existing neurons, and supports the growth of new neurons.
Personally, I think this is an exciting research area, and finding out how different exercise regimens specifically impact the cells of the immune system could yield interesting findings. I guess the big question is “What type of exercise should a person living with MS undertake, how often, for how long and at what intensity?”
Exercise is always going to be personal and needs to fit the capabilities and limitations of the individual. But take note, benefits have been published for people living with MS, in studies assessing aerobic exercise, resistance training, massage therapy and even Tai Chi!