A new study published in the journal Aging Cell by researchers at Temple University in Philadelphia, Pa., has found the brain mechanisms involved that further link stress to the onset of Alzheimer’s.
The study, led by Domenico Praticò, professor of pharmacology and microbiology and immunology in Temple’s School of Medicine, looked at past research on corticosteroid — a stress response hormone found at levels two to three times higher in the blood of patients with Alzheimer’s disease. Stress is known to be an environmental factor in Alzheimer’s and researchers wanted to add to this knowledge by studying what mechanisms were involved. They discovered early damage happens in the brain before the disease even occurs by finding that corticosteroid uses a brain enzyme called 5-lipoxygenase as a mechanism that damages the connection between neurons, leading to memory decline.
Scientists used triple transgenic mice — mice that contain genetic material transferred from another organism — that develop two brain abnormality signatures (amyloid beta and the tau protein) for the disease. Over the course of a week, one group of mice was injected with corticosteroid each day in order to mimic stress levels.
The mice did not suffer memory loss; however, scientists did find that the tau protein was significantly increased in the mice that received corticosteroid injections. The mice that did not contain 5-lipoxygenase seemed to show no neuronal damage. By inhibiting this 5-lipozygenase enzyme, it is believed to also block the effects of corticosteroid.
The Alzheimer Society of Canada cites stress as a risk factor in developing Alzheimer’s disease or another form of dementia — a disease diagnosed in more than 747,000 Canadians. They suggest reducing stress through meditation, deep breathing, massage and physical exercise.
Symptoms of chronic stress may include the following:
Emotional: depression, tension, anxiety, anger, worry, fear Physical: headache, fatigue, insomnia, sweating Mental: poor concentration, memory loss, indecisiveness, confusion Behavioural: fidgeting, overeating, alcohol and drug abuse
Rebecca Melnyk | 13/06/26 | Last Updated: 13/06/28 10:14 AM ET
The National Post