We tend to associate meditation practise primarily with benefits to mental health as oppose to physical health (though the two are inextricably linked, good mental health is associated with good physical health and vice versa), so I was interested to read this review of meditation and health by Kok (2013) at the Max Planck Institute for Human Cognitive and Brain Sciences, that explored the links between different meditation practices and their effects on immune function, cardiovascular function and pain perception, all of which are markers of physical health and predictors of longevity.
3 kinds of meditation were considered:
1. Focused attention: as the name suggests, attention is focused on a particular object or sensation, such as the breath, whilst excluding all other distractions.
2. Open-monitoring: in contrast to focused attention, this type of meditation is about moment to moment awareness of internal and external experience as it unfolds, without excluding any particular aspects of experience, all are paid attention to.
3. Kindness and compassion: with this type of meditation, attention is primarily focused on connection with others. Focus can be directed to the self, an individual or a group. Sometimes, there is no target and compassion is elicited without specific reference to anyone. The principal object of this meditation is to cultivate feelings of closeness and goodwill.
To recap, the researchers reviewed studies exploring the effects of meditation on 3 aspects of physical health: immune function, cardiovascular function and pain perception, going on to suggest potential mechanisms that might underpin the effects that they observed.
Immune system effects
A number of studies linking meditation to improved immune functioning were identified such as that by Jacobs (2011), a 3 month long study which looked at the effects of combined open-monitoring and kindness and compassion meditation training on telomerase activity in immune cells (telomerase is an enzyme of which higher levels are associated with lower levels of stress and better health). In comparison to a group of participants matched for age, sex, and BMI (body mass index), the meditation group showed greater immune system telomerase activity at the end of the study. The researchers suggest that open-monitoring meditation may lead to an increased capacity for self-regulation and non-reactivity of thoughts, resulting in more adaptive responses to stress, a beneficial effect given that the immune system can be adversely affected by stress. In regards to kindness and compassion meditation, they purport that an increase in the proportion of positive subjective experiences such as positive emotions and social closeness might be one mechanism behind the improved immune function associated with kindness based meditation practices. Kok quotes research by Fredrickson (2008) in which participants of an 8 week loving kindness meditation training reported a steady increase in daily positive emotions which was linked to increased growth in a range of resources including positive social relationships and self-reported physical health. These effects were observed in comparison to a wait-list control (WLC) group (a group in which the same measures are observed but participants do not engage in the intervention being studied).
Effects on cardiovascular functioning
In regards to cardiovascular functioning, one study quoted is that by Gregoski (2011) in which healthy African-American adolescents participated in 3 months of mindfulness-based stress reduction (MBSR) training. In comparison to life-skills training and health education training control conditions, the MBSR training led to significantly greater reductions in blood pressure. In a publication forthcoming, Kok observed that in comparison to a WLC group, 8 weeks of loving-kindness meditation led to increases in cardiac vagal tone, a measure of efficient parasympathetic functioning (parasympathetic being the aspect of the nervous system responsible for slowing activity in many of the body systems, including heart rate and enabling us to enter relaxation mode). Increased emotional regulation associated with open-monitoring and focused attention meditations (both are practiced in MBSR training) could potentially decrease emotional reactivity to negative events and bring about a speedier recovery to stress therefore leading to better cardiovascular functioning; a research study by Ortner (2007) observed that in comparison to relaxation meditation and a WLC group, mindfulness meditation was associated with decreased emotional reactivity to unpleasant pictures. Kindness based meditation practises may exert their effects by possibly increasing the likelihood of positive emotional experiences and promoting feelings of social closeness, both of which are associated with faster cardiovascular recovery from stress (Frederickson, 1998) and decreased likelihood of cardiovascular disease (Kok, 2010). In Kok’s forthcoming research the effects of vagal tone were mediated by changes in daily self reported positive emotions which in turn predicted changes in daily social closeness ratings. Increased social closeness led to improvement in cardiac vagal tone.
Pain perception
Looking at pain perception, a meta-analysis of 22 studies on chronic pain by Veehof (2011) revealed that open-monitoring meditation led to a reduction of self-reported pain intensity that was comparable to standard treatment. A pilot study exploring loving-kindness meditation reported decreases in pain, moreover participants reported lower pain ratings on the days that they practised loving-kindness meditation. In terms of acute pain, a study by Zeidan (2010) 3 days of 20 mins of mindfulness mediation led to increased pain tolerance relative to pre-training tolerance. The researchers suggest that potentially mindfulness driven emotional regulation may dampen feelings of chronic pain by decreasing the tendency to focus on bodily sensations whilst also anticipating future pain and simultaneously supporting present-focused non judgmental awareness.
The studies I mention above are only a small selection of the research quoted that observed effects of meditation on these 3 physical health factors and all support the notion that the benefits of meditation are multi-dimensional. Kok’s research affords us a greater appreciation for mind-body interactions and the interdependencies that exist between them and how this knowledge might be applied to improve aspects of mental health by bolstering physical health.