How does the structure of the brain change with age? What role do factors such as sports, alcohol and smoking play, and what distinguishes normal ageing from pathological changes? Researchers are investigating these and many other questions in the 1000BRAINS study. Scientists from Jülich, Düsseldorf, Essen and Basel have presented their first results.
Different brain regions age differently. The right hemisphere of the brain, in which, among other things, spatial thinking is positioned, apparently deteriorates more in old age than the left hemisphere, in which language is located, for example. This could explain why the spatial orientation and the visual working memory diminish in elderly people, while linguistic competence remains relatively constant throughout their lives. The frontal brain regions, in which conscious control is located, among other things, undergo a comparatively little deterioration. In addition, older people use more brain areas than young people to solve the same task. This is the so-called cognitive reserve. It allows to compensate for ageing processes to a certain degree.
Factors such as social contacts, alcohol consumption, smoking and physical activity leave behind clear traces in the brain. People who live in a busy social environment and also those who are active in sports show a lower volume loss of the brain in old age. This is an indication of a lower loss of nerve cells. High alcohol consumption, on the other hand, is associated with a greater loss of brain volume than would be appropriate for the age and indicates the destruction of nerve cells. The latter is considered to contribute to lower-level performance and flexibility in old age in terms of mental capabilities. Smoking, on the other hand, affects brain function rather than brain structure. The targeted cooperation of brain regions in the resting brain is higher in smokers than in non-smokers, so the brain is always busier. As a result, there is less cognitive reserve available than for non-smokers. For example, if certain brain regions fail due to ageing, smokers have less free capacity to activate other regions for these areas.
Older people are often prescribed B vitamins in order to maintain their memory capacity or to increase it again. These vitamins are intended to improve communication between nerve cells. Apparently, however, the effects and processing routes of B1 and B6 vitamins in the body are different than previously known. The results of the Jülich researchers show: in the case of vitamin B6, there always seem to be positive effects, no matter how high the levels are in the blood. This must mean: “A lot helps a lot.” In the case of vitamin B1, however, the researchers noticed that despite a high vitamin B1 level in the blood, a deterioration of the brain substance had taken place. Vitamin B1 probably does not reach the brain sufficiently in older people, as preliminary studies have shown. The causes of this need to be further researched in the future.
Those who intensively learn an additional language increase their brain volume – especially at the beginning of the learning process and in two specific areas. On the one hand, the changes can be seen in the lower back part of the frontal lobe where our motor speech centre is located. In addition, the lower parietal lobe changes as well. It is also involved in language and, in addition, combines various information into an overall impression. Jülich researchers have now been able to show how the areas age in multilingual people: on the one hand, the volume of the motor speech centre also decreases with age in people who speak several languages. On the other hand, however, it is only at a very old age that the region equals the volume of people who speak only one language. The second sector remains stable even longer. This could explain why multilingual people often stay mentally fit longer in old age.
1,300 clinical trial participants ranging mostly between ages of 55 and 85 have been examined by magnetic resonance imaging at the Jülich Institute of Neuroscience and Medicine since September 2011. Four years later, nearly 500 of them again took part in the examinations.
The brain scans are supplemented by data on the health and circumstances in the lives of the trial patients, including data from the Heinz Nixdorf Recall study on cardiovascular health conducted in Essen.
The dataset of the 1000BRAINS study comprises around 90 terabytes of data – roughly the volume of 90 hard disks of an off-the-shelf home computer. The information contained ranges from genetic data, blood values and brain images to statements about life circumstances. The experts estimate that it will take about ten years to comprehensively analyse this unique data treasure.
The evaluation of the 1000BRAINS study is still in its infancy. For example, the researchers are also investigating how playing musical instruments, nutrition, education or various environmental influences, such as particulate matter and noise, affect the ageing process. In doing this, they can look at several aspects at the same time – for example, whether playing a team sport has a particularly positive effect on the brain. In this way, effects can be discovered that only arise through the interaction of various factors.
“Our research impressively shows that a healthy lifestyle is also anatomically and functionally reflected in the brain.”
Prof. Svenja Caspers,Institute of Neuroscience and Medicine (INM-1)
Photo: Forschungszentrum Jülich/Sascha Kreklau