How sports can increase cognitive abilities and prevent depression.
It is well known that regular physical exercise (PE) improves health and longevity. Some of the best-described effects consist in ameliorating cardiovascular functionality by decreasing resting heart rate and blood pressure, regulating energy and glucose metabolism, and reducing inflammation.
But PE –in particular endurance exercise– also directly influences brain function, resulting in improved brain health and consequently further enhancing general health.
Research in the last decade has identified some of the main effects of exercise on the brain and has started to unravel the molecular mechanisms by which the physiological changes triggered by exercise modify the activity of neurons in the brain.
1. Enhance cognitive abilities
PE enhances cognitive abilities: PE increases the number of functional neurons in the hippocampus, a brain region that is involved in learning and memory. In addition, it enhances synaptic plasticity, which improves signal transmission between neurons and the processing of information.
These effects are mediated by factors such as brain-derived neurotrophic factor (BDNF), insulin-like growth factor-1 (IGF-1) and vascular endothelial cell growth factor (VEGF), whose concentration in the hippocampus is increased by PE.
2. Prevent brain damage
PE protects the brain from stress and injury: PE induces the production of neurotrophic factors in several brain regions that limit damage to neurons, promote their survival, and assure their proper function. BDNF, IGF-1 and VEGF play an important role also in this process together with other molecules such as fibroblast growth factor-2 (FGF-2), nerve growth factor (NGF), glial cell-derived neurotrophic factor (GDNF), and antioxidant and DNA repair enzymes.
3. Fight Alzheimer’s and Parkinson’s
PE protects against neurodegenerative diseases: PE can counteract Alzheimer’s and Parkinson’s diseases by reducing the accumulation of misfolded and aggregated proteins that are characteristic of these pathologies, and by promoting their elimination. PE exerts these effects by stimulating the production in the brain of molecules that control protein folding and facilitate the degradation of damaged proteins, and of neurotrophic factors (in particular BDNF) and neurochemicals that improve neuron survival and functionality.
4. Prevent depression
PE prevents and alleviates depression: several studies have shown that PE can have therapeutic effects similar to those of anti-depressant drugs. The mechanisms by which PE decreases depression are complex and may include the regulation of the stress response through the hypothalamus, and the release of BDNF and serotonin that affect mood, appetite, and cognitive functions. Whatever the mechanism, everybody who regularly exercises is familiar with the uplifting effects of aerobic and endurance activities.
But how does rhythmic and protracted muscle contraction, i.e. PE, produce its effects on the brain?
Changes in oxygen availability and consumption throughout the body induced by PE could contribute to the stimulation of brain activity. In addition, some still unidentified “exercise factor(s)” might be released from muscles during exercise, reach the brain and stimulate its functions.
In this respect a recent study published in Cell Metabolism showed that an ‘exercise factor’ is responsible for the increased levels of BDNF in the hippocampus during exercise. Since BDNF is one of the main mediators of the beneficial effects of PE on the brain, the identification of the exercise factor that induces it is of great medical interest. In fact, this exercise factor or a similar molecule could in principle be administered to patients in order to boost BDNF production in the brain for the prevention and treatment of a large variety of diseases, from neurodegenerative disorders to learning disabilities and depression.
Photo: Flickr, donjd2
Wrann CD, White JP, Salogiannnis J, Laznik-Bogoslavski D, Wu J, Ma D, Lin JD, Greenberg ME, & Spiegelman BM (2013). Exercise Induces Hippocampal BDNF through a PGC-1α/FNDC5 Pathway. Cell metabolism, 18 (5), 649-59 PMID: 24120943
Mattson MP (2012). Energy intake and exercise as determinants of brain health and vulnerability to injury and disease. Cell metabolism, 16 (6), 706-22 PMID: 23168220
Cotman CW, Berchtold NC, & Christie LA (2007). Exercise builds brain health: key roles of growth factor cascades and inflammation. Trends in neurosciences, 30 (9), 464-72 PMID: 17765329