Video and presentations of the Lifebrain webinar are now available
On June 10, 2020, the Lifebrain consortium and the Norwegian Brain Council jointly organized a webinar to present latest research findings on the impact of loneliness, depression and sleep on brain health. The webinar is available for replay. Links to the presentations from the webinar are provided below.
Anette Storstein from the Norwegian Brain Council opened the webinar by reiterating the importance of brain health for living an independent, socially active and fulfilling life. She reminded us that 1 of 3 European citizens will develop a brain disease some time during life. Dementia and stroke are major causes of death as well as mental disorders. She highlighted that mental and neurological disorders are interdependent and cannot be separated from each other. Maintaining a good brain health in populations is the next global health challenge.
PRESENTATION 1: Loneliness and memory change across Lifebrain European samples, Professor David Bartrés-Faz
Loneliness is a subjective state of psychological distress, associated with the feelings of being left out. Loneliness impacts at least 30 million people in Europe. According to previous studies, lonely people usually follow less healthy lifestyles, have worse sleep patterns, higher substance use, and poorer health than the general population. Depression, anxiety, cardiovascular diseases, obesity, and dementia can also impact perceived levels of loneliness via the immune system and stress hormones.
Using data from the Lifebrain cohorts mainly in Germany and Sweden, we found that loneliness may slightly accelerate memory decline in advanced age although its effect on age-associated memory decline is moderate. These results need to be interpreted with caution, as the underlying causality relations are not yet fully known. From our design we cannot say or know if loneliness causes memory decline with advanced age or that individuals that have more marked memory decline with age are then - as a consequence of greater cognitive impact - those that feel more lonely. We also found that it is persistent loneliness (feeling lonely for a longer period of time, constantly) but not temporary increase of loneliness related to sudden life events (for e.g. death of a partner) that seem to have an impact on memory and its age-associated decline.
Cultural differences could impact how loneliness is perceived. Some data from a European survey conducted on more than 100.000 individuals suggest that, given the same level of social isolation (i.e. people with few social contacts or living alone), countries of Southern-Europe (i.e. Italy, Spain) have greater ratings of perceived loneliness than in Northern Europe. Being “alone” may be experienced as more difficult in Southern Europe than up North. We have not yet been able to investigate if this cultural difference may associate with a distinct effect on cognition in the Lifebrain cohorts.
PRESENTATION 2: Associations of depressed mood and lifestyle with brain structure, PhD candidate Julia Binnewies
Previous research has suggested that depression and an unhealthy lifestyle, such as alcohol consumption, smoking, lack of physical activity, too much or too little sleep and higher BMI, may negatively impact brain structure. However, there is also a relation between depression and lifestyle as persons with depression often have an unhealthier lifestyle. Therefore, it is still unclear whether depression and lifestyle are indeed both independently associated with brain structure or whether these associations are driven by one of these factors. It is also known that a decrease in brain volumes is related to normal aging. However, we do not know precisely how depression and lifestyle affect brain changes over time.
The Netherlands Study of Depression and Anxiety (NESDA) is a member of the Lifebrain consortium. The NESDA researchers followed people with or without depression for 9 years. They could confirm that depression and BMI are associated with a lower thickness of certain prefrontal brain regions. The associations of depression and BMI on brain structure were independent of each other, so they were not driven by one of the factors. The researchers also found that moderate alcohol consumption is related to higher thickness of some prefrontal brain regions. However, this may also be related to the fact that non-drinkers might not be the healthiest population (“sick-quitter”): they may be persons who stopped smoking due to severe illnesses. No negative association between heavy alcohol consumption and brain structure was found. However, this could be explained by the small number of participants drinking heavily in the sample. Surprisingly, no associations were found between sleep duration, physical activity, and smoking, and brain structure.
Also, no associations of depression and lifestyle with change in brain structure over up to 9 years were found. Only trends were found for higher BMI and lower physical activity being predictive of more subsequent decrease in brain structure over time.
The potential causality of the relations described above are still unclear. More research will be conducted, including data from other Lifebrain cohorts, to investigate whether a healthy lifestyle and less depressive symptoms give a healthy brain later in life.
PRESENTATION 3: How are sleep and the brain related? Professor Anders M. Fjell
There has been a worry for a long time in modern society that people are sleeping too little. The National Sleep Association in the USA recommends a quite high number of hours of sleep for each night, however we do not know if and how sleep duration and sleep quality actually impacts brain health. Or is the causality the other way around, that people with not optimal brain health tend to get sleep problems?
In Lifebrain, we wanted to investigate how sleep quality and hippocampus changes are related over time. This is because hippocampus is a crucial brain area for memory. We found that those subjects who self-reported good sleep on average lost less hippocampus volume than those with bad sleep. This relation seems to be quite stable across life. Interestingly, sleep duration – the number of hours spent sleeping each night – is very weakly related to brain volume and does not seem to have a large negative impact on the brain in the long run. Brain volume only seems to be negatively affected when people sleep too much (more than 10 hours per night) or too little (less than 5 hours).
We also found that self- reported sleep problems are related to more amyloid in the brain – the main biomarker for Alzheimer’s Disease – but the relationship is not strong. We should however note that changes in sleep are normal in aging in general. More research will be needed to better understand the relationship between sleep and brain health across the lifespan.
PRESENTATION 4: Professor Christian A. Drevon on biomarkers of brain health
We know that what is healthy for the body is good for the brain. Factors related to lifestyle such as levels of physical activity, plasma concentration of cholesterol and glucose, blood pressure, alcohol consumption, smoking habits, sleep, diet and involvement in social networks all have an impact on brain health.
It is possible to use biomarkers to learn more about brain health, for instance:
- Vitamin D (25-hydroxy vitamin D3): low plasma level is associated with thinner cortex in certain parts of the brain
- Cholesterol: is associated with vessel health
- Omega-3 and Omega-6 fatty acids: influence brain structures and signals
- HbA1c: is a marker of diabetes mellitus
- Cytokines: signals from or to the brain like brain-derived neurotrophic factor (BDNF), Inflammation: e.g. interleukin 6 (IL6), c-reactive protein (CRP)
- Lipids: screening and heart health. Specifically, diacylglycerol with two double bonds (DAG 36:2) is reduced with sleep loss.
Lifebrain researchers are currently searching for more specific markers of brain health and potential candidates are DAG and BDNF. These biomarkers will be measured in more than 1700 dried blood samples (DBS) from the Lifebrain cohorts. The DBS data gained from these analyses will enrich the various other Lifebrain studies on brain and cognition.