Humans and other living organisms require oxygen to breathe. Oxygen enters the lungs when a person inhales, then diffuses through membranes into the red blood cells. It is then transported by these cells through the blood vessels to reach other cells throughout the body. It is essential to brain function and respiration and is a vital component of the metabolic process.
Oxygen allows the cell respiration and metabolism necessary for the growth of tissues, the conversion of food to energy and the reproduction of cells. The gas also provides heat and energy, and it oxidises or "burns" carbon dioxide and other waste materials to prevent them from poisoning the body.
The brain uses 20 percent of the oxygen a body consumes. Loss of cognition, memory or movement control can be due to reduced oxygen intake and subsequent lowered neuron activity. When neurons do not get enough oxygen, this leads to fatigue, irritability and depression. According to Oxygen-Review.com, this increases the risks of neurodegenerative diseases, such as Alzheimer's, Parkinson's and Huntington's disease. Brain cells begin dying within about five minutes of being deprived of oxygen.
Receiving oxygen treatments reportedly improves alertness, reflexes and memory. It protects against dementia, and it can help alcoholics to stop drinking. Mayo Clinic explains that hyperbaric oxygen therapy involves breathing pure oxygen in a pressurized chamber, providing the lungs with as much as three times more oxygen than normal.