Why the Brain?
For everything about the brain, order the book The Owners Manual for the Brain (1049 pp)
The brain makes up only 2 percent of our body weight, but it consumes 20 percent of the oxygen we breathe and 20 percent of the energy we consume. This enormous consumption of oxygen and energy fuels many thousands of chemical reactions in the brain every second. These chemical reactions underlie the actions and behaviors we use to respond to our environment. In short, the brain dictates the behaviors that allow us to survive.
Things we know, for sure.
It changes daily - in fact, it is now clear that neural plasticity allows the structure and function of the adult human brain to change significantly as a result of new experiences. Boyke J et al. Training-induced brain structure changes in the elderly. J Neurosci. 2008 Jul 9;28(28):7031-5. What we thought was fixed, (hopeless) science shows we can change, best of all it can happen at any age.
It controls everything - the brain is the master controller of the body. There is not one function that occurs that the brain did not initiate. It is estimated that every second yields 1017synaptic events in the brain. In other words, thats how many actions are being controlled and regulated by your brain every second. It starts to form in the embryo at 3 weeks and never stops changing until you die.
It experiences everything - there are millions of sensory organs spread throughout your body that are in direct contact with your brain. These organs sense your internal and external environment, send the information to your brain and then your brain make sense of it.
It is driven by movement of the spine - Roger Sperry, Nobel Prize Recipient, discovered that 90% of the stimulation and nutrition to the brain is generated by the movement of the spine. This is a powerful statement. Living an active lifestyle will protect your brain and ensuring that we have a healthy spine is a key component to a healthy brain.
Top Ten Myths about the Brain here is a quick outline of why we use 100% of our brain and not the myth of only 10%:
We live in an environment that challenges us daily, no wonder brain related diseases are epidemic.
Stress This can be both chemical and/or emotional (Physical would be more related to a past head trauma). Chemical stress increases oxidative stress to the brain, whereas emotional stress tips the brain into creating 1400 neurochemicals that, over time, will decrease brain function. Peters JL et al. Interaction of stress, lead burden, and age on cognition in older men: the VA Normative Aging Study. Environ Health Perspect. 2010 Apr;118(4):505-10
Inflammation - Chronic systemic inflammation induced by stimuli such as cigarette smoking, obesity, disrupted sleep patterns and poor dietary habits compromises the integrity of the blood-brain barrier, allowing irritants to enter the brain and stimulate the production of inflammatory cytokines. Inside the brain and spinal cord, these cytokines impairneurogenesis, the process by which new neurons are generated. Aside from inhibiting neurogenesis, some inflammatory cytokines damage and destroy existing neurons. Komulainen P et al. Serum high sensitivity C-reactive protein and cognitive function in elderly women. Age Ageing. 2007 Jul;36(4):443-8
Hormonal Imbalance - Distributed throughout the brain are steroid hormone receptors which function to regulate the transcription of a vast array of genes involved in cognition and behavior. When hormonal imbalances disrupt receptor activation, cognitive deficits and emotional turmoil are the result. Studies indicate the following hormones affect brain function: Estrogen, Testosterone, DHEA, Pregnenalone, Thyroid hormones, HDL, and Homocysteine, to name a few. Mani SK et al. Steroid hormone action in the brain: cross-talk between signalling pathways. J Neuroendocrinol. 2009 Mar;21(4):243-7
Hypertension - A case-control study of over 700 patients found a statistically significant correlation between blood pressure and rate of cognitive decline over a six-month period for subjects younger than 65 years.Bellew KM et al. Hypertension and the rate of cognitive decline in patients with dementia of the Alzheimer type. Alzheimer Dis Assoc Disord. 2004 Oct-Dec;18(4):208-13
Diabetes and Insulin Resistance - Individuals with diabetes displayed increased progression of brain atrophy, and performed less well on tests of cognitive performance and learning van Elderen et al. Progression of brain atrophy and cognitive decline in diabetes mellitus: a 3-year follow-up. Neurology. 2010 Sep 14;75(11):997-1002.
Obesity - Mid-life obesity was strongly linked to later-life dementia in over 1,000 participants in a longitudinal study carried out over a 36 year period. Subjects with the greatest waist diameters at baseline were nearly three-fold more likely to develop dementia over the following three decades.Whitmer RA et al. Central obesity and increased risk of dementia more than three decades later. Neurology. 2008 Sep 30;71(14):1057-64.
Anxiety and Stress - Increased anxiety is a predicator of earlier conversion from mild cognitive impairment to Alzheimers disease. Gallagher D et al. Anxiety and behavioural disturbance as markers of prodromal Alzheimer's disease in patients with mild cognitive impairment. Int J Geriatr Psychiatry. 2011 Feb;26(2):166-72
Depression - Several cognitive and neuropsychological deficits accompany depression, including impairments in executive function, attention, episodic memory, visuo-spatial skills and information processing.Crocco EA et al. How late-life depression affects cognition: neural mechanisms. Curr Psychiatry Rep. 2010 Feb;12(1):34-8
Social Connections Social networks and personal relationships have a strong protective factor on brain health. Among 2,249 women aged 78 or older, those with smaller social networks at baseline had a significantly greater chance of having developed dementia within one year than women with larger social networks. Crooks VC et al. Social network, cognitive function, and dementia incidence among elderly women. Am J Public Health. 2008 Jul;98(7):1221-7.
Activity - A critical driving force behind neural plasticity (and therefore overall cognitive function) is a protein called brain-derived neurotrophic factor (BDNF). BDNF acts upon areas of the brain involved in learning, memory, and higher-order thinking to stimulate formation of new neurons, survival of existing neurons, and synaptic adaptation. Low levels of BDNF are observed in a variety of brain disorders, including cognitive decline, depression, dementia, and Alzheimers disease. Physical exercise is known to enhance cognitive function as it leads to an increase in levels of BDNF. Several studies have demonstrated that exercise induces (intensity-dependent) increases in BDNF levels in humans.Yarrow JF et al.Training augments resistance exercise induced elevation of circulating brain derived neurotrophic factor (BDNF). Neurosci Lett. 2010 Jul 26;479(2):161-5