Role of physical activity and diet on mood, behavior, and cognition

Research on the relationship between physical activity and mental health reveals that physical activity exerts beneficial effects on emotional and cognitive functioning. Studies clearly indicate that aerobic exercise is neuroprotective. It seems that the activity-dependent production of nitric oxide (NO) and the anti-inflammatory effects of regular exercise may play an important role in the production of brain-derived neutrophic factor (BDNF) that occurs in response to exercise. With regard to behavioral functioning, most studies focus on the influence of physical activity on depressive symptoms or affective disorders. Physical exercise upregulates the production of several neurotransmitters which like serotonin are associated with mood enhancement and reduced depressive symptoms. The positive effects of physical activity on anxious mood and anxiety disorders are also well documented. Thereby cytokine-induiced effects on nitric oxide formation and activity of indoleamine 2,3-dioxygenase (IDO) as well as the formation of tetrahydrobiopterin (BH4), cofactor of several amino acids monooxygenases, seem to be special relevance. Improved self-esteem and self-efficacy seem to play an important part. Physical activity also affects the endocrine stress-regulation system: trained people exhibit stronger reactivity and quicker regeneration when faced with stressful events. However, aerobic exercise does not improve mental health in every case, as seen for instance in over-trained athletes associated with fatigue, disturbed mood and signs of depression might emerge. Recent research has provided exciting evidence for the influence of dietary factors on specific molecular systems and mechanisms that maintain mental function, for instance, a diet that is rich in omega-3 fatty acids.