What’s the science behind meditation?
Meditation has caught the interest of the scientiﬁc, community sparking considerable excitement as more and more evidence of its beneﬁts are recognised. But what’s the science behind meditation?
The 1990’s, known as the ‘decade of the brain’, saw an increasing amount of scientific evidence supporting the beneficial effects of meditation. It has been shown to have a measurable beneﬁcial effect on both the brain and the body.
The science bit
Neurons transmit brain waves. These change depending on our thoughts, feelings and activity, and can be measured using an electroencephalogram.
Delta waves (1-3 Hz) are low, slow frequency brain waves. They are associated with deep, dreamless sleep. Theta waves (4-8 Hz) are known as the creativity waves. They are highly active in 2-5 year olds, the age at which we are most imaginative. In adults, they are seen in deep relaxation, meditation, dreaming and mental imagery. Alpha waves (9-13 Hz) are seen in relaxed wakefulness and in meditative states.
As a person meditates the waves slow and an increase in alpha waves is seen. Enhanced levels of alpha and theta waves signify relaxed alertness and are conducive to mental health.
Beta waves (14-30 Hz) are seen in awake, alert consciousness. These are fast waves and the more stressed we become, the more intense these beta waves become. Gamma waves (40-70 Hz) are the fastest brain waves. They allow a simultaneous passing of information from different brain areas and rapid processing of information.
As a person meditates the waves slow and an increase in alpha waves is seen. As a deeper state of meditation is reached there is an increase in theta waves. Enhanced levels of alpha and theta waves signify relaxed alertness and are conducive to mental health.
How meditation affects the brain
New neurons develop in the brain in response to experience (this is called neuroplasticity), and meditation has this effect.
MRI studies show that there following meditation there are changes in the areas involved in attention, executive functions and memory. There is better emotional regulation and reduced amygdala (the fear centre) reactivity seen on fMRI.
Numerous studies show that the structure of the brain is altered by meditation. Regional cerebral blood ﬂow is enhanced to the areas of the brain responsible for executive function.
Meditation leads to improved memory, and an enhanced ability to cultivate positive emotions and retain emotional stability.
Meditation has also been shown to slow brain atrophy and increase cortical thickness. Increased grey matter in the the frontal and hippocampal areas of the brain following meditation lead to improved memory, and an enhanced ability to cultivate positive emotions and retain emotional stability.
Wider benefits of meditation
Beneﬁts are also seen within the body, right down to cellular level. Meditation improves overall health and immune system function. A trial measuring the effects of a three month meditation retreat on the activity of the Telomerase enzyme, which is linked with improved cell longevity, conﬁrmed a signiﬁcant greater activity in retreat participants. This essentially means that when we practice meditation we do not age as quickly or become prone to disease so early.
Beneﬁts are seen within the body, right down to cellular level. Meditation improves overall health and immune system function.
Meditation and the immune system
Another trial showed improved immune system function and less stress response in participants. Meditation was even shown to be better than exercise in its ability to improve our immune system against the cold virus!
Mediation, blood pressure and heart function
Blood pressure has also been shown to reduce during a trial comparing an 8 week mindfulness meditation to health education talks. Participants were similar in both groups, but randomised to each intervention. A signiﬁcant reduction in blood pressure was seen in those practicing meditation after 8 weeks.
A statement from the American Heart Association following a study of over 400 trials is that meditation possibly reduces cardiovascular disease risk and so can be added to patient management, given the low risk of harm.
Meditation and mental health
Mental health can be improved with meditation. Stress, anxiety and depression is reduced, resulting in improved quality of life.
There is also a beneﬁt in cancer survivors with a brief meditation program leading to less stress and less inﬂammation response within the body.
Beneﬁts to both mind and body
Meditation appears to have beneﬁts to both mind and body, as well as enhancing a sense of wellbeing and purpose in life.
Given the low cost and low risk of harm, it’s an exciting possibility that this can be implemented in anyone’s life and result in beneﬁt. More research is currently being done, with better quality trials, and so the future is full of promising evidence.
A positive conclusion to a positive practice!
Want to explore meditation? Read my beginner’s guide on How to Meditate.
You can also listen to my free meditations here.