Meditation is an ancient Buddhist tradition that focuses on living in the moment. In recent years, medical research has attempted to document whether meditation techniques, do in fact, have a specific physiological effect on brain tissue.
In modern clinical practice, meditation is often recommended to treat stress, anxiety, depression, and pain. Medical evidence is accumulating to show that meditation does indeed have biological effects on distinct regions of the brain.
Meditation has been shown to affect the brain in the following ways. Meditation quietens the sympathetic nervous system
Several studies have shown that meditation can dampen down the sympathetic nervous system (SNS) – the body’s involuntary nervous system that deals with stress. The stress response functions via a nerve pathway that involves the hypothalamus and pituitary gland, and the neurotransmitter, noradrenaline.
In a small 2005 study, 19 patients with congestive heart failure were split into 2 groups. One group was asked to listen to a meditation audiotape twice a day for 12 weeks and participate in a weekly meeting. Those in the control group went to the meeting only.
At the end of the study, there was a significant reduction in blood levels of noradrenaline, when compared to the control group, as well as improvements in the Living with Heart Failure Questionnaire, along with an improvement in some of the markers of cardiac function.
In another 2012 study, 201 African Americans at risk of heart disease, average age 59 years, were randomly allocated to either a group asked to practice Transcendental Meditation (TM) twice a day, or a control group who had health education advice only. After 9 years, there was a significant reduction in cardiovascular events in the TM group, plus a 4.9 mm Hg reduction in blood pressure.
The authors believed the main reason for the improved heart disease outcomes was due to the fall in blood pressure. They commented on the fact previous studies have shown meditation deactivates the SNS.
In fact, meditation stimulates the complementary pathway - the parasympathetic nervous system (PSNS). When you meditate, this induces feelings of calm and relaxation.
Changes to the frontal cortex
The frontal lobe is regarded as the most highly evolved part of the brain.This is where most of our emotions and thought processes, such as problem-solving, reasoning, and planning, take place. During meditation, the frontal lobes tend to switch off and rest.
In a 2005 study run by American neurologists, MRI scans were conducted on the brains of 20 adults who regularly practised Buddhist Insight Meditation. Certain areas of the frontal cortex were found to be thicker than those of a group of matched controls who did not meditate. These were areas of the brain associated with attention, interoception (how you interpret feelings within your own body), and sensory perception. These differences were most marked in the older age group. As the cortex tends to thin with age, the authors suggested that meditation might help prevent age-related cortical thinning.
The difference in cortical thickness was most pronounced in areas of the right hemisphere, specifically those regions linked to increasing awareness of sensations such as breathing – a feature of meditation. The same areas are involved in emotion and cognition. The authors suggested that regular meditation may be a mechanism to help build coping strategies for life stresses.
Regularly participating in meditation, helps you to feel calmer and not overreact to emotional situations.
Changes to the white matter
The white matter of the brain is situated underneath the grey matter of the peripheral cortex. Although it makes up about half the brain volume, it has been the subject of relatively little research. White matter takes its name because of the white myelin sheath that coats all the white matter axons.
Two studies have shown that meditation increases the volume of the corpus callosum – a vital brain structure where fibres connect one side of the brain to the other. Meditation led to an increased density of white matter in the sagittal stratum, and the corona radiata, and was linked to an improvement in mood.
Another key area of white matter known as the superior longitudinal fasciculus, which connects the front, the sides, and the back of the brain, has also been shown to be larger, in those who regularly meditate. This part of the brain provides attention, motor control, auditory processing, and language, amongst many other functions.
The fact that meditation strengthens these areas of white matter, may explain why meditation can help regulate emotions.
Experts have found that when using a form of automated pattern recognition, the brains of those who meditate regularly look younger than the brains of those who do not.
Meditation may help slow ageing
Telomere shortening is a recognised feature of ageing. Telomeres are DNA segments situated on the ends of chromosomes. The length of telomeres has been found to be associated with cognitive decline and dementia and is hence regarded as a measure of the ageing brain. However, those who practice regular meditation have been found to have increased telomerase activity. Telomerase is an enzyme used to repair damage to telomeres.Perhaps meditation leads to less stress and less brain inflammation. Meditation has been shown to be associated with lowered levels of C reactive protein and interleukin (IL)-6, both markers of inflammation.
Meditation lowers brain inflammation
In addition to lowered levels of C-reactive protein and interleukin (IL)-6, research on regular meditators has shown this to be linked to reduced levels of nuclear factor-kappa B (NF-κB) - a cell-signalling molecule with a major role in the immune response.
Although this may have some benefits and some disadvantages, experts think that overall, this is beneficial, as it results in lowered brain inflammation. It also increases the sensitivity of brain neurons to the stress hormone, cortisol. This means the same effects are achieved at lower concentrations, hence leading to a reduction in cortisol levels. Lowered cortisol levels are linked to less brain shrinkage with ageing.
Final thoughts
There are so many benefits from meditation. As we face old age, if meditation can help keep our brains in good health, help preserve mental functions, support plasticity (the development of new neuronal connections), help us cope with our emotions, and delay brain shrinkage and ageing – it would seem a perfect past-time! After all, it’s drug-free, reduces stress, and is also highly enjoyable.
