The finding came from new research that was conducted on mice and led by Sara Bengtsson, a PhD student at Umea University in Sweden. Similarly, a prior study conducted at the University of Gothenburg, Sweden indicated that psychological stress in middle age could cause dementia later in life, especially Alzheimer's disease.
The new study examined the association between levels of stress hormones in the brains of the animals and their memories. Bengtsson discovered that the mice that were more stressed did not remember as well as the animals which were less stressed. Results also showed that highly stressed mice had larger amounts of proteins known as beta-amyloids in their brains, which are associated with Alzheimer's disease.
Beta-amyloids were linked to Alzheimer's disease in a 2007 study presented the 54th Annual Meeting of SNM, the world's largest society for molecular imaging and nuclear medicine professionals.
"Beta-amyloid is associated with brain dysfunction - even in apparently normal elderly individuals - providing further evidence that it is likely related to the fundamental cause of Alzheimer's disease," said Christopher Rowe, director of the nuclear medicine department and Centre for PET at Austin Hospital in Melbourne, Victoria, Australia.
High levels of beta-amyloids are known to lead to the malfunction of brain synapses, resulting in memory problems and other symptoms of Alzheimer's, which affects about 500,000 people in Britain.
It is crucial to remember that this study was not conducted in humans, Dr Simon Ridley, head of research at the charity Alzheimer's Research UK, pointed out:
"Some research has already highlighted a possible link between chronic stress, cognitive decline and the development of Alzheimer's, and further study in people is needed to fully investigate these links.
If we can better understand the risk factors for Alzheimer's we can also empower people to make lifestyle changes to reduce their risk."
However, there is strong evidence showing that the likelihood of developing Alzheimer's disease lowers when people use their brain intensively throughout life, for example:
- having an intellectually demanding job
- being bilingual
Written by Sarah Glynn