All the brain does is process information that is vital to the body, and all the body does is provide a life support system for the brain so that we can reproduce our species and control some of the forces of evolution that try to wipe out our species.  It begins this processing with non-conscious emotional scrutiny of just about every bit of information that comes in, taking just milliseconds to make up your mind for you, as to how you will feel about this information when you finally become consciously aware of it for the first time, a bit later on, at around the half second mark.

You then begin to think about the information, and how you feel about it, both really colored by the automatic emotional response that came before you knew what had happened.  Now that you have time to think about this new information, and how you feel about it, you can bring in your capacity to control events and feelings, taking minutes, hours, days, weeks or years to process events, and act on them to maximize the best outcome for yourself, namely, your capacity for self regulation.  To succeed in life, your brain has to manage your immediate responses so that the best future outcome for you is assured.  Some do it better than others.

The brain has around a 100 billion brain cells, and each cell has hundreds of thousands of connections with other cells, not one of them touching: the brain communicates across gaps called synapses, using chemical messengers called neurotransmitters. There are lots of these, some related to mood, eg serotonin, some related to reward, such as dopamine. Others, such as GABA calm down the brain, others, such as Glutamate, excite the brain, and can be quite dangerous if they are tampered with, such as by using alcohol or other drugs which disturb the body brain balance.  Some of these neurotransmitters are found outside the brain, and many events in the body such as exercise provide vital substances which enhance the brain.  Hence, it is wrong to think of the body and brain as separate in some ways: you can separate most bits of your body and still live on, such as an arm, pancreas, gall bladder, bits of gut etc, but separating the body and brain from each other is fatal.

When either dies, the other is useless.  What is good for your body is generally good for your brain, and knowing which aspects are especially good for the brain is the basis of Body-Brain Vitality.  However, the modern environment, with its pollutants, challenges, stresses, poor nutrition, and stresses, is not the one the brain and body evolved in, and hence the need for us to change our lifestyles to result in Brain and Body boosting to optimize brain health.