Keep the brain fit into old age

Aging Society: How the brain stays fit in old age

01/11/2014

Almost 1.5 million people in Germany suffer from dementia. Worldwide, according to WHO estimates, a total of 35 million are affected. Scientists have long been concerned with mental decline. Although there is no such thing as a miracle cure for brain aging, there are indications as to how the brain can be kept fit even into old age.

The challenge of aging societies
Artists and scholars like Titian, Socrates or Leonardo da Vinci were intellectually very active even at the end of their lives. However, this is far from the case with all seniors. As older people increase, so does their share of the total population in many countries. Degenerative diseases such as dementia are a major challenge for aging societies. According to estimates by the World Health Organization (WHO), around 35 million people around the world suffer from dementia. In Germany almost 1.5 million of them are affected.

Spiritual decay dependent on hereditary factors and life factors
In the journal „Science“ Ulman Lindenberger from the Max Planck Institute for Human Development in Berlin writes, according to a news agency dpa, that it varies greatly when and how strongly a person is affected by mental deterioration. Among other things, this depends on hereditary factors and vital factors such as stress and intellectual demands. In the same magazine, Sarah Harper of the University of Oxford writes that as many as 60 people across the globe in 2050 will already be in the same age group as young people under 15. The proportion of over 80s will multiply by then. In the US alone, about three times as many people will be Alzheimer's disease patients by 2050 as they are today. Researchers at the Rush University Medical Center in Chicago forecast that the number will increase from 4.7 million in 2010 to 13.8 million.

Physical and mental decline
Alzheimer's is the most common form of dementia. Experts predict a doubling in Germany from 1.4 million to around three million people with dementia by 2050, which will result in an immensely increased nursing burden. According to Lindenberger, cognitive performance generally decreases with age. However, today not only physical, but also mental decline begin on average later than in earlier times with lower life expectancy. In addition, there are ways to influence mental decline. „Long-term studies indicate that losing an intellectually challenging, physically active and socially engaged life can reduce losses and increase profits.“ As the expert emphasized, however, should not give the impression that the brain aging is completely under their own control. This is just as wrong as saying that development can not be influenced, not even gradually.

Research still in the beginning
However, research is still at an early stage in terms of which environmental factors and experiences influence how and to what extent on the aging of the brain. But what has already been shown is that the messenger substance dopamine plays an important role. „A number of results from patient studies, animal studies, pharmacological influence, and molecular genetics suggest that dopamine is crucial for mental performance.“ Although there are significant differences from person to person, the amount of gray and white matter decreases with age. „The lateral prefrontal cortex, the prefrontal white matter and the hippocampus are among the regions in which there are particularly large individual differences in age-related brain atrophy“, so Lindenberger. Often, risk factors such as stress affect exactly these regions.

Learn new language and play with grandchildren
According to this, the declining plasticity of the brain, the ability of synapses, nerve cells and entire brain areas to change and adapt to new demands and influences are also among the variables. The Berlin researcher also suspects an interaction of supply and demand as a factor, ie the question of whether the brain still has to master new tasks at all. Sometimes the plasticity can sometimes be partially improved, for example by learning a new language or dealing with lively grandchildren. Norbert Smetak, chairman of the Federal Association of Established Cardiologists (BNK), also announced earlier this year that studies indicate that the brain of senior citizens also benefits from regular endurance sports. Since there is no effective drug against Alzheimer's disease, experts recommend again and again to use existing opportunities for prevention and treatment. For example, it is known that the treatment of diabetes and hypertension reduces the risk of developing dementia.

Research has long focused on decay of the brain
Angela Gutchess of Brandeis University in Waltham, Massachusetts writes in another „Science“-Article that the aging of the brain is as complex and idiosyncratic as the brain itself. Thus, research has long focused on decay - inferior hearing and vision, increasing forgetfulness, slower information processing, and increased difficulty in filtering relevant and irrelevant information. But today we know that even an aging brain maintains a certain degree of plasticity, which also includes the formation of new nerve cells. A promising approach is brain stimulation with targeted current pulses, but the number of such studies with older participants is still low.

Terms are often „on the tongue“
Meredith Shafto and Lorraine Tyler from the UK University of Cambridge explain in „Science“, that the skills little influenced by age included many language processes. Although the vocabulary improves for the better part of life, it declines in old age. In speech production, this is different: it slows and deteriorates among seniors in comparison to younger ones. That terms more and more often „on the tongue“ lie, but are not tangible, is another typical sign of the normal aging process. Mostly, the intellectual strength of a human remains a lifetime. This is also shown worldwide by unique data from Scotland. At the beginning of the 20th century, the government feared that the intelligentsia would be dwindling. Therefore, large-scale intelligence tests were initiated, which took place over decades. In 1997, the results were accidentally rediscovered by researchers around Ian Deary in the basement of the University of Edinburgh, writes „Science“-Author Emily Underwood in another post of the series.

Study participants tracked down after decades
Through letters and advertisements, the psychologist's team tracked down thousands of former participants and asked them to retake the test. As Underwood explains, many of the seniors, however, had no interest in having their dwindling brain activity recorded. However, more than 500 participants in the 1932 test and more than 1,000 in the I47 1947 IQ study returned to the questionnaires from 2003, with a variety of other analyzes. Underwood writes that comparing the results now provides a unique opportunity to track brain aging. The seniors' brains were scanned, their genes analyzed and their habits recorded.

IQ test at the age of eleven years
It is said that the mental faculties in old age can be predicted with one factor better than any other individual feature: the result of the IQ test at the age of eleven. Although there are many exceptions, ie people whose IQ results turned out much better or worse in old age. But overall, the data from Scotland supported a casual „Water tank hypothesis“ quoted theory, as cited by Nicholas Martin of the QIMR Berghofer Medical Research Institute in Herston, Australia. The better a brain functions in childhood thanks to genetic influences and favorable environmental factors, the more cognitive reserves can be lost in old age. „The fuller the tank is at take-off, the longer it takes for it to be empty.“ (Ad)