About the Brain
The brain is the centre of our nervous system and the most metabolically active organ in the body. It is made up of about 100 billion neurons and weighs about 1300 g. The brain is divided into 4 parts: the brain stem, the lower end of which is a continuation of the spinal cord; diencephalon; cerebellum; and cerebrum, which makes up about 7/8 of the total weight of the brain and occupies most of the cranium.
The brain is protected by the meninges, a covering that surrounds it and is continuous with the spinal meninges. The cranium is the boney casing that protects the brain. Additional protection is offered to the brain and the rest of the central nervous system via the cerebrospinal fluid (CSF) which has an action like that of a shock absorber. The CSF circulates through and around the brain and spinal cord and helps reduce trauma to this part of the body by providing a cushioning action.
The brain utilises about 20 per cent of the oxygen used by the body, with the variance in level of oxygen used depending on the degree of mental activity. The blood supply to the brain is crucial for survival and unconsciousness may result from an interruption to the blood flow. The healthy function of the brain depends on a variety of factors, the most important being the blood supply to the brain and the nutrient and oxygen content of that blood. Under normal circumstances, the brain uses a continual supply of glucose as its source of energy. Without constant replenishment the glucose reserves of the brain will be used in approximately 10 minutes.
A selective barrier called the blood brain barrier protects the brain cells from harmful substances. This barrier allows the selective passage of various substances into the brain cells and inhibits passage of others that are harmful to the brain such as proteins, or drugs such as antibiotics.
Balanced, regular meals throughout the day are important to provide the brain with an adequate fuel supply. Start the day with breakfast - there is increasing evidence that eating breakfast is associated with better memory and mood later in the morning. A diet high in antioxidant containing foods, such as fruits and vegetables, nuts and seeds is important for brain health. Additionally, deep sea fish that are high in omega 3 fatty acids provide DHA, an important component of the brain tissue.
ADD - avoid preservatives, colourings, artificial flavourings, check for food sensitivities and allergies. A fresh, whole food diet incorporating fruit, vegetables, whole grains and white and lean meats is important.
Alzheimer's Disease/Dementias - It has been found that a high-fat diet during early adulthood may contribute to the risk of developing Alzheimer's disease so intake of fatty foods (particularly those high in saturated fat) should be minimised.
A diet high in the B vitamins folate, B12 and B6 helps to minimise homocysteine levels. Folate is found in foods such as leafy green vegetables, pulses, whole grains and nuts; vitamin B6 (pyridoxine) is found most commonly in vegetable foods particularly in whole grains, bananas, nuts and pulses; vitamin B12 (cyanocobalamin) is most commonly found in meats or dairy products, however, in non-animal products it is confined to mushrooms and the alga spirulina.
Research indicates that regular exercise is associated with significant reduction of risk of Alzheimer's disease, dementia and other forms of cognitive decline. Exercise increase increases circulation, including circulation to the head area and therefore increases blood flow and nutrition to the brain. It has been demonstrated that vigorous exercise is most beneficial to mental function, however, even low intensity exercise such as walking can be helpful. A 1995 study found that the distance required to provide benefit from walking is approximately 1.6 km or 1000 steps.
Most research indicates a strong genetic component to Alzheimer's disease and other dementias, however, there are factors that certainly contribute to the incidence of the condition that are avoidable.
Minimisation of exposure to environmental pollutants - brain tissue is particularly susceptible to damage from free radicals.
Avoidance of head trauma - history of head trauma in addition to genetic predisposition to Alzheimer's generates a ten fold risk of the condition.
Avoidance of medications associated with dementias eg sleep aids, sedatives, antidepressants.
Minimisation of chronic emotional stress. Research has demonstrated that poor stress coping mechanisms are associated with atrophy of the part of the brain responsible for memory acquisition and accelerated cognitive deterioration.
Studies indicate that considerable oxidative damage is present in Alzheimer's disease. It is thought that antioxidant nutrients, particularly vitamin E, may slow neurodegeneration and delay or even aid prevention of the disease.
Infancy and childhood is a crucial period for the development of the brain and nervous system. Nutrients play an important role during development and deficiencies during this time may lead to children not achieving their full mental potential.
Adequate dietary iron levels are important for children and aid proper mental development.
Intake of DHA - found in breast milk and fish oils - during pregnancy and the first 6 months of life (via the breast milk) aids the brain and visual development of infants.
Supplements Can Help
Where risk factors or known deficiencies are present, the use of supplements may be helpful to support brain health. Vitamin E helps reduce damage from free radicals and has been clinically trialled and found to attenuate the progress of Alzheimer's disease at doses of 2000 IU per day. Essential fatty acids: DHA is an important component of the brain tissue and is prone to oxidation. Use of fish oils which contain DHA may be helpful. Iron: Iron deficiency anaemia can contribute to reduced mental development of infants and children. In some populations supplementation with iron is recommended. Ginkgo biloba: Is a herb which has been extensively trialled for cognitive problems linked to vascular insufficiency and memory loss. Ginkgo biloba may help slow progression of age related memory loss when used at doses of 120-150mg of concentrated extract per day.