Iulia O. Basu-Zharku writes on health and spirituality: “The difficulty in conceptualizing spirituality/religion comes from the multidimensionality of these concepts, and extends to the problem of how exactly spirituality/religion influence health. This, in turn, emphasizes the fact that there are multiple interpretations of how spirituality/religion influences health and a number of pathways through which this happens.
Four most prominent such pathways have been proposed: health behaviors (through prescribing a certain diet and/or discouraging the abuse of alcoholic beverages, smoking, etc., religion can protect and promote a healthy lifestyle), social support (people can experience social contact with co-religionists and have a web of social relations that can help and protect whenever the case), psychological states (religious people can experience a better mental health, more positive psychological states, more optimism and faith, which in turn can lead to a better physical state due to less stress) and ‘psi’ influences (supernatural laws that govern ‘energies’ not currently comprehended by science but possibly understandable at some point by science). Because spirituality/religion influence health through these pathways, they act in an indirect way on health (Oman & Thorensen, 2002).
Moreover, four interpretations of how spirituality/religion influence health have been proposed. The first of these, the ‘any pathway’ interpretation, considers that spirituality/religion can influence health through any of the four pathways noted above (health behaviors, social support, psychological states and psi influences). The second interpretation, the ‘psychobiological’ one, considers that spirituality/religion influence health through psychoneuroimmunological or psychoneuroendocrinological pathways beyond the benefits that religion has through health behaviors and social support.
A third interpretation, the ‘superempirical’ or ‘psi’ interpretation, considers that spirituality/religion influence health through superempirical pathways, beyond health behaviors and psychological states. Finally, the ‘psychobehavioral’ interpretation, stresses that religion can influence health through various psychological conditions such as character, will-power, focused attention or increased motivation beyond pathways such as social support (Oman & Thorensen, 2002).
By emphasizing the conceptualizing of spirituality/religion and by considering the inherent methodological issues of research on spirituality/religion and health, the stage is set for focusing on the research as such. Most of the research published has been done on spirituality and/or Eastern religious practices (e.g., meditation, yoga, relaxation exercises) and health. Other research has looked at Judeo/Christian/Muslim religious practices (in particular, synagogue/church/mosque attendance and/or prayer) and health.
The research investigating the influences of spirituality and various Eastern religious practices, such as yoga or various types of meditation, is extensive (Seeman, Fagan-Dubin & Seeman, 2003). Many of these studies look into the relationship between meditation and various physiological measures. Because the literature is so extensive, only some representative studies will be cited here. The most documented relationship is the influence of meditation on blood pressure (Patel et al., 1985; Sudsuang, Chentanez & Veluvan, 1991; Schneider et al., 1995; Schmidt, Wijga, Von Zur Muhlen, Brabant & Wagner, 1997). In a randomized, longitudinal study, the influence of meditation/relaxation techniques on the incidence of cardiovascular disease (participants were judged as being at high risk for it if they had two or three of the following risk factors: smoking, high blood pressure and high cholesterol) was investigated (Patel et al., 1985).
Results showed that at eight weeks, eight months and four years afterwards, the participants that followed the meditation/relaxation techniques program had a significantly lower blood pressure. A second study involving a randomized design looked at the influence of transcendental meditation and progressive muscle relaxation on blood pressure in a sample of older African American adults (Schneider et al., 1995). The group in the transcendental meditation condition showed reduced systolic and diastolic pressure significantly more (almost twice) than the group in the progressive muscle relaxation, and the group in the life-style education classes. This study is very interesting considering the sample used. Most of the studies usually use White or Asian, male, college students as participants. However, an important issue of these studies is that they did not address meditation as a religious/spiritual practice.
Another study compared a group of individuals from a residential area in Sweden participated in a three-month yoga and meditation training program with a group of individuals from a residential area in Germany that did not participate in the program (Schmidt et al., 1997). The Swedish participants showed decreased blood pressure following the three months program (especially those with elevated levels) compared to the German participants. Finally, a group of male college students that followed a Dhammakaya Buddhist meditation program showed a reduction in systolic and diastolic pressure, compared to a control group of male college students that did not follow the program (Sudsuang et al. 1991).
This last study also showed that the college students following the meditation program had lower stress hormone levels (specifically cortisol) at the end of the program (Sudsuang et al., 1991). Another study that also looked at cortisol levels in a control group of young adults, this same group after 3-4 months of practicing transcendental meditation, and another group, of long-time (3-5 years) practitioners of transcendental meditation (Jevning, Wilson & Davidson, 1978).
For the control group, the levels of cortisol did not change, while for the short-term practice of meditation, the levels decreased but not significantly. For the long-term practitioners, however, the cortisol levels deceased significantly and remained like that after the sessions of meditation. In addition, Walton, Pugh, Gelderloss and Macrae (1995), in a cross-sectional study, investigated the differences in the levels of various hormones and minerals between healthy, young adults who did not practice any stress-reducing technique and a similar group that had practiced transcendental meditation for a long time. The latter group showed lower levels of cortisol, aldosterone and norepinephrine.
One other study analyzed levels of cortisol, β-endorphin and adrenocorticotropic hormone (ACTH) in two groups: one of practitioners of transcendental meditation and another of non-practitioners (Infante et al., 1998). Results showed that the meditation practitioners had no diurnal rhythm for ACTH and for β-endorphin, as compared to the control group. However, a methodological issue of the last three studies is that they did not make use of randomization, relying on data from groups of individuals that had already practiced or not meditation (Seeman et al., 2003). Ironson et al. (2002) found that private religious and spiritual feelings were associated with long survival in HIV-positive and AIDS patients, and the having a general sense of peace was strongly related to lower levels of cortisol, and thus showing that physiological benefits might come from non-organized spiritual beliefs.
The literature on spirituality and Eastern religious practices is extensive. From the studies cited here, some evidence for the existence of a relationship between meditation and health exists. Specifically, the relationship between mediation/relaxation techniques and blood pressure seem to have the strongest evidence (Seeman et al., 2003), while the other relationships between meditation/relaxation techniques and stress hormones, oxidative stress.