Tuesday, January 22, 2013

Stress and Disease



 Cancer and Stress
The relationship between cancer and stress is not well-defined. Price et al. (2001) found no independent relationship between women and their stressful life experiences, but those who lacked an adequate social support system showed a higher risk for breast cancer. Michael et al. (2009) did not find strong enough evidence to link stress with this type of cancer. One study found care giving roles for women were protective for breast cancer, likely because the stress decreased the women's amount of female hormones (Kroenke et al., 2004). These same hormones, when found in excess are thought to contribute to breast cancer (Kroenke et al., 2004). In a study that evaluated over 11,000 women over nine years, Surtees, Wainwright, Luben, Khaw, and Bingham (2010) found no association between stressful events and the development of breast cancer. This study is perhaps more significant than other studies because the authors considered the individual differences, such as coping skills, that can mediate the overall effects of the stressors.

Brown et al., (2010) found a relationship between adverse childhood experiences and the initiation of smoking behavior, which contributed to an increased risk of lung cancer. Brown et al. suggested the stress incurred in childhood encouraged self medicating (with nicotine) but also found the stress affected parts of the brain that mediate responses to stress. Simply stated, these same processes contribute to sustained inflammation, which has been shown to contribute to the risk of cancer development (Brown et al., 2010). Perhaps the most interesting finding in Brown et al. was that they believed there were other unidentified reasons for premature death from lung cancer that were not explained by smoking. I found this extremely interesting because many alternative practitioners such as naturopaths and acupuncturists, believe an association exists between diseases of the lung and grief and sadness. This concept is based is based on the ancient Chinese 5-element theory.

Although there exists a common lay belief in an association between stress and the risk of cancer, Bergelt, Prescott, Grønbæk, Koch, & Johansen (2006) found a definitive correlation between stress and the development of unhealthy lifestyles, but no significant association between stress and the development of cancer. Further, no link was found between cancer development and depression and other psychological issues, life stressors, or personality traits (Bergelt et al., 2006). Both stress and the development of cancer have become commonplace in contemporary life. Perhaps studies will develop other, more specific means of measuring this relationship that will eventually determine an association between the two.

Stress and Infectious Disease
Ample research suggests a relationship exists between the immune system and stress (Deckers, 2010; Murray, Marks, Evans, & Estacio, 2011). The field of psychoneuroimmunology has long held the belief that psychological insults to the nervous system directly affect the immune system. Cohen and Williamson (1991) found a positive relationship between stress and upper respiratory illness, a suggestive, but inconclusive relationship between stress and herpes viruses, and a generally consistent association between stress and bacterial infections. Additionally, stress increased susceptibility to colds and respiratory infections (Cohen, Tyrrell, & Smith, 199; Cohen & Williamson, 1991).

In a study that examined all Danish children born between 1977 and 2004, Nielson, Hansen, Simonsen, & Hviid, (2012) found increased stress during childhood contributed to a biological susceptibility to infectious disease. Decreased immunity seems to render individuals more susceptible to a host of diseases, although even under extreme conditions, not all individuals become susceptible (Herbert & Cohen, 1993). Although an abundance of evidence suggests stress affects immunity which can lead to disease, a missing component may be that individual differences are the significant determinates of risk factors. Understanding the specifics of individuals (such as coping styles, personality type, and genetics) may lead to effective treatment designs as well as personalized strategies for circumventing illness overall (Buckley, 2011; Schmidt, Sterlemann, & Müller, 2008; Zozulya, Gabaeva, Sokolov, Surkina, & Kost, 2008).

References

Bergelt, C. C., Prescott, E. E., Grønbæk, M. M., Koch, U. U., & Johansen, C. C. (2006). Stressful life events and cancer risk. British Journal Of Cancer, 95(11), 1579-1581. doi:10.1038/sj.bjc.6603471

Brown, D. W., Anda, R. F., Felitti, V. J., Edwards, V. J., Malarcher, A., Croft, J. B., & Giles, W. H. (2010). Adverse childhood experiences are associated with the risk of lung cancer: A prospective cohort study. BMC Public Health, 10(1), 20. doi: 10.1186/1471-2458-10-20

Buckley, R. (2011). Infectious Disease Genomics: Individual Variability, New Opportunities. MD Conference Express, 4-5.

Cohen, S., & Williamson, G. M. (1991). Stress and infectious disease in humans. Psychological Bulletin, 109(1), 5-24. doi:10.1037/0033-2909.109.1.5

Cohen. S,. Tyrrell, U. & Smith, A. (1991). Psychological stress and susceptibility to the common cold. New England journal of Medicine,325, 606-612.

Deckers, L. (2010). Motivation: Biological, Psychological, and Environmental, (Chapter 8), (3rd ed.). Boston: Pearson/Allyn & Bacon

Herbert, T. B., & Cohen, S. (1993). Depression and immunity: A meta-analytic review. Psychological Bulletin, 113(3), 472-486. doi:10.1037/0033-2909.113.3.472

Kroenke, C. H., Hankinson, S. E., Schernhammer, E. S., Coditz, G. A., Kawachi, I., & Holmes, M. D. (2004). Caregiving stress, endogenous sex steroid hormone levels, and breast cancer incidence. American Journal of Epidemiology, 159, 1019–1027.

Marks, D. F., Murray, M., Evans, B., & Estacio, E. V. (2011). Health Psychology: Theory, Research, and Practice (3rd ed.). London: Sage.

Michael, Y. L., Carlson, N. E., Chlebowski, R. T., Aickin, M., Weihs, K. L., Ockene, J. K., & ... Ritenbaugh, C. (2009). Influence of stressors on breast cancer incidence in the Women's Health Initiative. Health Psychology, 28(2), 137-146. doi:10.1037/a0012982

Nielsen, N., Hansen, A., Simonsen, J., & Hviid, A. (2012). Stressful life events in childhood and risk of infectious disease hospitalization. European Journal Of Pediatrics, 171(1), 173-179. doi:10.1007/s00431-011-1498-2

Price, M. A., Tennant, C. C., Butow, P. N., Smith, R. C., Kennedy, J. S., Kossoff, M. B., et al. (2001). The role of psychosocial factors in the development of breast carcinoma: Part II. Life event stressors, social support, defense style, and emotional control and their interactions [Abstract]. Cancer, 91, 686–697.

Schmidt, M. V., Sterlemann, V., & Müller, M. B. (2008). Chronic Stress and Individual Vulnerability. Annals Of The New York Academy Of Sciences, 1148174-183. doi:10.1196/annals.1410.017

Surtees, P., Wainwright, N., Luben, R., Khaw, K., & Bingham, S. (2010). No evidence that social stress is associated with breast cancer incidence. Breast Cancer Research And Treatment, 120(1), 169-174. doi:10.1007/s10549-009-0454-6

Zozulya, A., Gabaeva, M., Sokolov, O., Surkina, I., & Kost, N., (2008). Personality, coping style, and constitutional neuroimmunology. Journal Of Immunotoxicology, 5(2), 221-225.doi:10.1080/15476910802131444



No comments:

Post a Comment