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When Buddha was still Prince Siddharta, he often slipped out of the palace where his father had shut him away to look around the neighbourhood. During one outing he saw a white-haired, toothless hunchback with a wrinkled face who was grumbling. He was amazed and the coachman explained to him that he was an old man. ‘What a disgrace’ exclaimed the prince ‘that weak and ignorant people, full of their own youthful pride do not see old age! Let’s go home immediately. What value do games and pleasures have if I am the home of future old age?’
In our society it is impossible ‘not to see’ old age given that in the second half of the 20th century an increase of over 100% was recorded in the population between 60 and 79 years of age and about 300% in those over 80 years old. Average life expectancy is now 75 years for men and 80 for women and this is likely to rise in the next few years, so much so that now a fourth age is being talked about. But what does ageing mean?
From the biological point of view, there are two opposing hypothesis groups. One states that ageing is a passive process caused by the accumulation of toxic products in the organism, a kind of organism exhaustion. The other states that ageing is an active process, a kind of programmed self-destruction in which the organism accumulates damaging changes and self-destructs. All the same, it is difficult to define what normal ageing is, notwithstanding the fact that the threshold for the onset of this stage in life is conventionally fixed at 65 years of age.
How people age varies greatly from person to person - even more when speaking of cerebral ageing, in which life history and environmental influences predominate. A series of changes occur in the brain through ageing: Its volume decreases and its weight and the blood vessels that bring nutrients to the brain alter. When the brain of an old person is seen under the microscope, fewer cells in the nervous system (neurons) are seen.
Above all, this occurs in two well-defined areas. The hippocampus, a structure in the brain that resembles the form of a sea-horse, is very important for the memory, and an area at the back of the brain is also very important for paying attention to something. Furthermore, the production of particular substances called neurotransmitters in the elderly brain also changes. By using these substances the neurons communicate between each other, as if in a relay race. The function of some neurons is to excite the nervous system and others to inhibit the nervous system. The strongest-acting substances are acetylcholine, important for the memory; noradrenalin, for emotional sensitivity and attention; dopamine, for controlling movement and emotions; serotonin, which is important for moods and the regulation of sleep; and GABA, which has an inhibitory action on the brain.
Ageing of the brain is therefore a very complex phenomenon. All these changes bring about areduced ability to learn, particularly of recent information, and in being attentive. Elderly people can have considerable difficulty concentrating and difficulty doing more than one thing at a time. In addition, ageing brings a slowing down of speech and a certain amount of difficulty in retrieving words and in planning a speech. There are great variations in these changes from one elderly person to another because they depend on educational level and lifestyle.
Thanks to the ability of the brain to modify itself as a result of training and its ability to process the same information in many ways, the normal processes of ageing can be slowed down and prevented. However, a good lifestyle is needed, composed of physical exercise, a balanced diet, stress release and daily exercises for the brain.
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