Effects of Exercise on BDNF Protein Levels in MS

Research Summary: Brain derived neurotrophic factor in multiple sclerosis: effect of 24 weeks endurance and resistance training

The background

Brain derived neurotrophic factor (BDNF) is a protein that plays an important role in the maintenance and repair of the nervous system.  For this reason, it has been a molecule of interest in multiple sclerosis research.  Previous studies have managed to identify the following:

• People with MS have lower resting levels of BDNF compared to healthy individuals
• The levels of BDNF increase in people with MS after a relapse, indicating they may play a protective role during remission

Interestingly, studies have also shown that, in healthy individuals, the levels of BDNF can be increased via exercise.  It is also known that the intensity of this exercise is important to achieve these results.  The effect of exercise on BDNF levels in people with MS has been studied, however, the results have been conflicting.

The study

This study by the REVAL Rehabilitation Research Centre, the University of Antwerp and Aarhus University aimed to not only confirm the difference in BDNF levels between people with MS and healthy controls, but also assess the effect of an exercise program on these levels in people with MS.

The study included 22 people with MS and 19 healthy individuals.  Following the initial assessment, the people with MS were divided into either an exercise intervention group (15 people) or a sedentary group (7 people).  The exercise group participated in a 24 week program that consisted of 5 sessions every fortnight.  The sessions contained a cardiovascular component (such as cycling or treadmill walking/running) and a resistance component (such as leg presses, arm curls and leg extensions).  The training increased in intensity and duration across the 24 week period.

The findings

The results of the study were as follows:

• Confirming previous findings, people with MS had lower baseline levels of BDNF than healthy individuals.
• Muscle strength and exercise capacity both increased in the exercise group, indicating that a combined resistance and endurance training program has a variety of benefits and is well tolerated by people with MS
• A significant difference was observed in the change in BDNF levels between the exercise group and the sedentary group at the end of the 24 week program.  Levels had increased by approximately 14% in the exercise group, whereas they had decreased by 10.5% in the sedentary group

The outcomes

Whilst we know that exercise has many beneficial impacts on our lives, this is one of the first studies to show that it could have the potential to alter proteins in the body important for nervous system repair.  As this is a relatively small study, larger studies taken over longer time periods will need to be performed to confirm these results.  It will also be of interest to see if the elevated levels of BDNF lead to any sustained improvements in clinical outcomes for people with MS.  As the levels of exercise that can be tolerated by people living with MS vary greatly, any undertaking of a new exercise program should be formulated in conjunction with a physiotherapist and/or neurologist.

The abstract of this study can be found here.