Stress Affects Brain Function and Structure

Echouffo-Tcheugui et al., from Harvard Medical School, recently published a paper studying the effects of stress on brain function and structure in over 2000 middle-aged participants from the Framingham Heart Study. They measured early morning serum cortisol as an indicator of stress levels. They found that “higher cortisol was associated with worse memory and visual perception, as well as lower total cerebral brain and occipital and frontal lobar gray matter volumes. The association of cortisol with total cerebral brain volume varied by sex (p for interaction = 0.048); higher cortisol was inversely associated with cerebral brain volume in women (p = 0.001) but not in men (p = 0.717)“.

The authors commented on the importance of finding ways to manage stress, “such as getting enough sleep, engaging in moderate exercise and incorporating relaxation techniques into their daily lives“.

Relaxation For Health And Well-Being

The word ‘stress’ has become ubiquitous, but what exactly does it mean? It’s probably in the 1920s that it was first used in its present context. Walter Cannon used it to describe the process where external factors disturbed the body’s natural equilibrium. Around the same time, Hans Selye described stress as the non-specific response of the body to any demand placed upon it. Still confused?

Let’s put things a little more clearly. To ensure our survival we must either be in ‘protection mode’ or in ‘growth mode’. Protection mode ensures our short-term survival i.e. running away from or slaying a sabre-toothed tiger, moving out of the way of an oncoming car, etc. Growth mode ensures our long-term survival i.e. taking in nutrients by eating and digesting a meal, recharging our batteries by sleeping, wound-healing, having sex and reproducing, etc. Protection mode is more commonly known as ‘fight-or-flight’ and growth mode as ‘rest-and-digest’. They are like two sides of the same coin…it’s either one or the other…we’re either in ‘fight-or-flight’ or we’re in ‘rest-and-digest’. You may be more familiar with ‘fight-or-flight’ or the stress response as it’s also known.

The stress response kicks in as soon as we sense a threat. Things start off in the amygdala deep inside our brains. Other areas of the brain (hypothalamus, pituitary gland) also become involved as does the sympathetic nervous system. The adrenal glands then release adrenaline and cortisol. The aim is to quickly prepare the body for vigorous muscle activity by releasing fats and glucose into the blood stream, increasing the heart rate and breathing rate, dilating blood vessels in muscles, increasing blood pressure and increasing muscle tension. All this helps get us immediately primed for action without having to go through any mental preparation or physical warm-up! It sounds too good to be true and it’s helped us survive and thrive through time. Fortunately nowadays, we don’t often face the type of physical emergency the fight-or-flight system was designed for…but our brains still perceive lots of threats out there…traffic jams, time pressures, bad bosses, financial worries, difficult partners, noisy kids, not to mention 24/7 connectivity, contactability and accountability with the advent of new technology! All this ends up firing off our stress response in a completely different context than that for which it was designed. Rather than a sporadic short blast, it’s now more of a constant slow simmer…without the physical activity required to reset the system. Almost like preparing for a battle that never arrives…revving a car that never goes anywhere.

This ongoing low-level stress response has negative consequences. According to the Mayo Clinic, if left unchecked, “stress can contribute to health problems such as high blood pressure, heart disease, obesity and diabetes”. They cite the following common effects of stress:

What’s the solution? The key is to find a way of getting ourselves back into ‘rest-and-digest’ mode. In 1968 Herbert Benson, a cardiologist from Harvard Medical School, fortuitously stumbled across something whilst studying blood pressure. He had been approached by a group of transcendental meditators claiming they could lower their blood pressures through the use of their minds! Initially sceptical and reluctant to study them, he eventually succumbed and discovered what he called the ‘relaxation response’. Benson described the relaxation response as the opposite of the ‘fight-or-flight’ or stress response, it’s essentially the ‘rest-and-digest’ mode mentioned earlier. He characterised it by:

• Decreased metabolism, heart rate, blood pressure and rate of breathing
• A decrease or calming in brain activity
• An increase in attention and decision-making functions of the brain
• Changes in gene activity that are the opposite of those associated with stress

Research has found that the relaxation response can be effective in treating the following complaints:

Additionally, research shows that mind-body techniques can also be effective in treating the following:

In summary, any symptom or disease caused or exacerbated by stress can be helped by relaxation. Happily, there are lots of ways to evoke the relaxation response such as relaxation techniques (progressive relaxation, passive muscular relaxation, Mitchell method, breathing exercises, etc.), meditation, prayer, yoga, tai chi, exercise, cognitive behavioural therapy and hypnosis.

Hypnosis is a personal favourite of mine. It can combine the immediate relaxing effects of relaxation techniques with a change in thinking, mood and behaviour such as can be obtained using CBT. Better still, because it uses the power of the unconscious mind, these changes take place effortlessly…as if by magic!

Give it a go (click on the icon to go directly to the shop)!

Relax and enjoy better physical health and mental well-being.

Exercise Prevents Stress

A lot of us know from experience that exercise is a great stress buster. Elizabeth Gould (Professor of Psychology at Princeton) and her associates have clarified the process. Their research was published in the March issue of the Journal of Neuroscience.

Their experiments were performed on mice. The mice were divided into 2 groups:

• Sedentary group: no running wheel
• Active group: free access to a running wheel (mice run about 4 km per day when given a running wheel!)

Six weeks later the mice were exposed to a stressor (cold water). The sedentary group showed an increase in ‘immediate early genes’ (short-lived genes that turn on rapidly when neurons fire). Whereas the active group showed no presence of these genes suggesting no neuronal excitation secondary to the stressor. In the active group, inhibitory neurons were more active and more gamma-aminobutyric acid (GABA) was released in the brain. GABA is a neurotransmitter that calms down neural excitement.

Gould concluded that “the results suggest that running improves anxiety regulation by engaging local inhibitory mechanisms in the ventral hippocampus”. In layman’s terms, this means that exercise prevents stress and anxiety by suppressing brain agitation.

Stress Management Could Help Decrease Pain

A recent study by Dr. Pierre Rainville and Étienne Vachon-Presseau from the University of Montreal has shed some light on the relationships between stress, the brain and pain. Their study compared 16 patients with chronic back pain with a control group of 18 healthy subjects. They found that back pain patients had higher levels of cortisol than subjects from the control group. Cortisol is produced by the adrenal glands and is secreted in response to stress. It’s a steroid hormone that increases blood sugar levels, suppresses the immune system, and may decrease bone formation; so an excess, particularly when maintained over a long period, is detrimental to health. The higher cortisol levels were associated with smaller hippocampal volumes. The hippocampus is a part of the brain that is involved in learning, memory and regulation of emotion. People with depression and post-traumatic stress disorder have been found to have hippocampal atrophy. The subjects with chronic back pain had stronger responses to pain stimuli in a brain region involved in anticipatory anxiety in relation to pain. Brain activity in response to the painful stimulus partly reflected the intensity of the patient’s current clinical pain condition.

The findings can be summarised in the following flow chart.

The authors suggest that stress management techniques such as relaxation and meditation should be used to complement medical treatments in patients with pain. They believe this can help to decrease the impact of pain and perhaps even prevent chronicity.

Acupuncture Helps Reduce Stress

An article in today’s Mail Online reviews research carried out on the effects of acupuncture on stressed rats. The results show that acupuncture can reduce the levels of a protein linked to stress. Apparently this is the first study to show molecular proof of the benefit of acupuncture on stress.