Five common myths about aging of the brain and body
The world's population is aging. The number of people over the age of 65 is growing, as well as the proportion of the population represented by them. At the same time, there are a number of myths among the people concerning what happens to the human brain and body as it ages.
1. Dementia is an integral part of aging
The incidence of dementia increases with age. Thus, the older a person is, the higher his chances of getting a diagnosis of dementia. However, if you managed to live to an advanced age, this does not mean at all that you suffer from dementia. Dementia is a clinical diagnosis characterized by impaired cognitive or cognitive functions (the ability to think) and functional abilities (allowing a person to live independently).
The main type of dementia is Alzheimer's disease, but there are many more types of this pathology, such as vascular dementia (caused by changes in the vessels of the brain, such as stroke), frontotemporal dementia (atrophy of brain tissue, most pronounced in the frontal and temporal lobes of the cerebral cortex), dementia with Lewy bodies (associated with the formation of specific protein aggregates known as Levi's corpuscles) and mixed dementia, which is a complex of different forms of the disease.
At the age of 65-69, less than 2% of people are diagnosed with dementia, but at the age of 90 and older, this figure increases to more than 30%. The flip side of this coin is that almost 70% of people aged 90 and older do not suffer from dementia.
2. Cognitive functions begin to fade after 20 years
The concept of "cognitive functions" extends to a person's ability to think, but in reality there are many parameters of thinking. For example, the speed with which a person reacts to information (the speed of information processing), the ability to memorize objects (general memory) and knowledge of words and their meanings (vocabulary). These components of cognitive functions demonstrate different patterns of change throughout adult life.
The speed of information processing and general memory really fade after 20 years, which means an increase in reaction time to various stimuli and an aggravation of forgetfulness. However, this pattern does not apply to vocabulary. On average, the vocabulary reaches its maximum after 60 years and subsequently practically does not decrease. A lot of studies have shown that the older a person is, the better results he demonstrates when solving New York Times crosswords.
3. The risk of dementia cannot be changed
According to statistical estimates, up to 30% of dementia cases worldwide can be prevented by lifestyle correction. According to existing data, factors of heart disease development that occur in middle age, especially diabetes mellitus, high blood pressure, obesity and lack of physical activity, increase the risk of developing dementia in old age. Depression, smoking and low level of education play the same role.
Therefore, to reduce the risk of developing dementia, it is necessary to reduce the impact of risk factors for heart disease, for example, increase the amount of physical activity and, if necessary, normalize body weight. It has been established that participation in cognitive-stimulating activities, such as formal (for example, university) and informal (short-term courses) education, as well as social events, reduces the risk of developing dementia.
These data are in perfect agreement with the results of recent studies conducted in Europe and the United States, which demonstrated that the risk of developing dementia has decreased over the past 20 years. Why? Apparently, today's elderly people are healthier both physically and in terms of cognitive functions than their predecessors.
4. If my parents had dementia, I can't avoid it either
Late-life dementia, diagnosed after the age of 65, is only to a very small extent due to genes inherited by a person from his parents. A total of 9 genes have been identified that increase or decrease the risk of developing dementia. The most influential is the apolipoprotein E gene. The presence of a combination of two E4 alleles in the genome increases the risk of developing dementia by 15 times compared to the more common E3E3 combination. All other genes have a negligible effect, increasing or reducing the risk of developing the disease by 20%. When viewed in a broad context, genetic risks are less pronounced than each of the lifestyle factors mentioned above. So, dementia is more likely to be caused by obesity (the probability is 60% higher) or a low-activity lifestyle (the probability is 80% higher). These comparisons are not accurate, since the genes associated with dementia may also be associated with the listed lifestyle factors, but they demonstrate the power of these factors.
5. Body weight should be constant
According to the elementary physical laws of energy conservation, if the amount of calories consumed corresponds to the amount of energy burned, the body weight will remain more or less constant. Most people believe in this simple and truthful food dogma, but do not take into account the significant impact of aging on energy metabolism.
As we age, the composition of body tissues changes. In particular, there is a reciprocal change in the amount of fat (increase) and muscle tissue (decrease), and different models of these changes are characteristic for women and men. Men are characterized by a more dramatic decrease in muscle mass, which causes a decrease in total energy costs by about 3% over a decade.
In women, the rate of these changes is slightly less than in men (by about 2% per decade). In simple words, this means that if you do not change your diet and training regime, with age it will lead to an increase in body weight, mainly due to fat deposits.
Aging is not a passive biological process. We should better understand our body and the changes that occur with it, which will allow us to maintain good health and prevent the development of age-related diseases, such as dementia.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of The Conversation: Five common myths about the aging brain and body.
09.02.2017