Stress and Alzheimer’s Disease

By Ram Rao, Ph.D., Principal Research Scientist for Apollo Health

We live in a hyper-competitive and stressful world thanks to global urbanization, competition, and the spread of technology. Stress comes from a multitude of reasons, including but not limited to financial problems, workplace tensions, job stability, relationship problems, domestic issues, school/college, social media, among others. Add to that list the COVID pandemic, and you will notice that stress has encapsulated the very fabric of humanity. If one were to compare the statistics of stress and its effects worldwide, it is interesting to note that the numbers are nearly similar worldwide. Within the USA, nearly 33% of Americans live with extreme stress. While acute short stress is good and has a positive impact, many Americans report chronic stress severely impacts relationships and work productivity. Finances and work are the two leading causes of stress; 48% of Americans believe that their stress has increased over the past five years, 72% of adults report that finance is their single cause of stress, 50% of Americans report that stress has a negative impact on both their personal and professional lives. Nearly 50% of adults report that they are not doing enough to manage their stress.

Chronic stress affects every aspect of people’s lives, from work to personal relationships to sleep patterns and eating habits. This has a toll on people’s health — contributing to numerous physical, psychological, and behavioral problems. The adverse effects of stress at the physical and mental level include:

● effects on lung capacity and function and episodes of hyperventilation leading to asthma and panic attacks
● hypertension
● failure of liver’s metabolic and detoxification functions leading to metabolic disorders like Type-2 diabetes and obesity
● irregular menstrual cycles and decreased libido
● improper digestion and absorption of nutrients leading to malabsorption and other inflammatory conditions in the gut
● insomnia and/or fatigue
● chronic anxiety or depression
● weakened immune system
● unexplained systemic pain

Furthermore, recent studies suggest that chronic stress may be one of the factors involved in the development of Alzheimer’s disease (AD) and could be due to a dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, a pathway in the brain that is responsible for stress responses. There is an intimate interplay between exposure to chronic stress and the brain’s immune system that is regulated by the HPA axis. In addition to modulating chronic stress, the HPA axis via several hormones regulates other bodily processes, including digestion, mood, emotions, libido, metabolism, energy, and the immune system. One of the hormones regulated by the HPA axis is cortisol which is released in response to stress. Low levels of the hormone have beneficial effects such as protecting the body from stressful situations, providing more energy, increasing physical and mental performance and memory recall. However, sustained high levels of cortisol, as seen during chronic stress, damage the brain’s memory centers and reduces the ability to learn and retain new information. Both dysregulation of the HPA and elevated cortisol levels are commonly seen in people with AD.

People should not think that having high-stress levels means they will develop AD, since stress alone may not cause AD. Still, it is one among many factors that determine whether AD symptoms will manifest earlier or later if someone is already going to get the disease. Patients with high levels of stress may have less of an ability to cope with the pathological changes of AD, and their symptoms may accelerate compared to those without high-stress levels. 

Health status is affected among those who manage their stress life very poorly. Stress management techniques vary among the general public. It is common to see stressed individuals overindulging in unhealthy habits, including poor eating habits and dietary choices, smoking, poor quality sleep, seeking out sedentary activities, etc., all of which affect the brain further. Interestingly, literature searches on stress management unanimously describe the positive impact of mindfulness, meditation, guided relaxation, Qigong, Tai Chi, and Yoga in alleviating stress. These activities also serve as the foundation of the Bredesen Seven.

Scientific studies have demonstrated numerous benefits, including rejuvenating the body and mind from any of the above-mentioned stress management techniques. Participants not only showed improvement in their physical parameters, but short sessions daily added a cognitive boost as well. The reasoning is simple: Stress management techniques destress the mind and body through numerous mechanisms including, 

(a) releasing brain chemicals that contribute to a feel-good response and ward off anxiety and mental stress, 
(b) normalizing blood pressure and stabilizing the heart
(c) reducing anxiety and depression
(d) improving the ability to sleep by de-activating the hypothalamic-pituitary-adrenal stimulus (HPA) and lowering the hyperarousal phenomenon,

Making the commitment to take care of yourself by incorporating stress management techniques daily may seem to be a huge undertaking, but remember, not only does it empower you — it keeps your brain active and free from the mercy of stressful forces.