Greater Life-Expectancy among Females Than Males - Assignment Example

Greater Life-expectancy among Females than Males al Affiliation Greater Life-expectancy among Females than Males It is a universal fact that men possess particular physical advantages over women. For instance, on an average, men are faster, taller, physically stronger, and less likely to be overweight. However, none of these features matter over the long-run. Such physical advantages are not found helpful in context of life expectancy. Over the years, various researches and studies on human lifespan have regularly shown that females tend to enjoy greater life-expectancy than males. In all developed states and majority of developing and third world countries, women outlast men almost by a difference of as much as 9-10 years. The mortality rates for women are less than those for men at all ages (Perls & Fretts, 1998). There is a widespread debate over potential causes of greater life-expectancy among women than men. Even though there are not yet solid answers, findings of most of the researches and studies implicate biological as well as behavioral differences between the genders, differences in the impact of medical technologies, as well as psychological and social factors for existing margin in lifespan of men and women. The purpose of this paper is to investigate potential reasons behind significant life-expectancy gap between males and females on the basis of available data and research findings. Trends in Life-expectancy Life –expectancy rates remarkably changed in the 20th century. The margin in lifespan between educated and non-educated, whites and non-whites, rich and poor has steadily decreased. However, the life-expectancy gap among the genders has become even wider. Both the genders have experienced huge but unequal rise in lifespan at birth over the last century. Between 1901 and 2005, US male life expectancy increased from 46.2 to 75.3 years, and US female life expectancy increased from 48.2 to 80.5 years (Rogers et al., 2010, p. 555). In the US, the gender margin in life expectancy at birth was merely a year in 1920 which slowly rose to a peak of 7.9 years between 1975 and 1980. But, since 1980, the gender gap in lifespan at birth in the US has regularly declined to 5.3 years in 2005, marking the lowest level in the last 70 years (Rogers et al., 2010, p. 555-556). The research of Wingard (1983) on the basis of Alameda County statistics showed that females aged 30-70 had a 52% lower risk of death compared to males from the similar age-group over the 9-year study period. After adjusting for risky behaviors such as alcohol consumption, smoking, and social behaviors such as marital status, and healthy behaviors such as diet, physical activities, the research further found that relative risk of mortality among males further increased from 52% to 72% (Rogers et al., 2010, p. 556). According to the 2005 reports of the National Center for Health Statistics (NCHS), males had greater age-adjusted mortality rates for 12 out of 15 major causes of death (Rogers et al., 2010, p. 556-557). The 2002 health report of the World Health Organization (WHO) reported that female life-expectancy surpassed male life-expectancy in all over the world except, Botswana, Nepal, Bangladesh, Zimbabwe, Swaziland, and Lesotho (Barford et al., 2006, p. 808). The 2004 report of the WHO stated that the life-expectancy trend in all 6 countries reversed, but 2 other countries namely, the Maldives and Qatar, reported the greater life expectancy of men than women (Barford et al., 2006, p. 808). However, the 2006 report of the US Central Intelligence Agency (CIA) updated the latest trend in life-expectancy all over the world which clearly showed that the women from the Maldives and Qatar overtook men in lifespan gap. Furthermore, the year 2006 was marked as the first year in human history when the female life-expectancy exceeded the male life-expectancy in all over the world (Barford et al., 2006, p. 808). Major Causes of Greater Life-expectancy among Females Biological Causes From the very early years of life, in the absence of any external influence that could impact on the mortality of individuals, male mortality is noted 25 to 35% higher than the female mortality, giving the genetic advantage to women. Genetically, women possess two chromosomes; while men have only one X chromosome (men have an X chromosome and Y chromosome) (Blue, 2008). When cell suffer from damage and aging, they have a variant in context of genes, either on 1 X chromosome or the other. In a way, if 1 set of variations of genes gives a survival advantage for such damaging and aging cells versus other sets of variations of genes, then these cells adopt advantageous set of variations of genes on X chromosome, leading to the greater number of cells with better variation of genes on the 2nd X chromosome (Blue, 2008). As men don’t have a luxury of 2nd X chromosome, aging process is faster in them than that in females. In other words, the genetic difference between males and females is linked with a better resistance to biological aging (Scientific American, 2004). Further, according to many scientists, including researchers of Imperial College School of Medicine in the UK, women may possess greater lifespan than men due to their relatively stronger immune mechanism (Hope, 2014). They found that women generate higher number of infection-resistant white blood cells than men of the same age. The research team led by Dr. Jeffary Lopez and Dr. Richard Aspinal tested particular new white cells, i.e., T-cells, in 50 healthy women and men aged between 20 and 63 (Hope, 2014). In both genders, the thymus gland, which develops T-cells, produced fewer cells with growing age. Yet women still had significantly greater number of new T-cells than men from the same age-group. When researchers compared the data for deaths in the UK from influenza and pneumonia between 1992 and 1999, they found more men than women died from the diseases (Hope, 2014). According to Dr. Aspinal, during older ages, when old T-cells are not as active and effective, capability of replacing higher number of old T-cells with new-ones proved to be advantageous for women (Hope, 2014). Furthermore, the role of women in reproduction and the female hormones have been associated with greater life-expectancy. For instance, estrogen, a female hormone, triggers the elimination of unhealthy cholesterol, offering protection against cardiovascular diseases till a certain level (Rogers et al., 2010, p. 559). High concentrations of C-reactive protein (CRP) lower the body’s capability to fight viruses and heal wounds, and are linked with both biological and behavioral risk factors such as low levels of physical activities, smoking, diabetes, heart attack, obesity, stroke, and high blood pressure. A meta-analysis of data about the CRP levels in both sexes found lower levels of CRP in women than men, reducing the risk of death from sever diseases like, cardiovascular diseases, certain cancers, diabetes, arthritis, and Alzheimer’s disease among females (Rogers et al., 2010, p. 559). Also, iron-deficiency compared to males is considered as one of the major reason for delay in development of cardiovascular diseases among women. Iron plays a vital role in the reactions in cells that generate damaging free radicals, which impair cell DNA and membranes, and may result into aging the cell (Blue, 2008). In women, by means of menstruation process, irons are regularly eliminated from the body, lowering the levels of iron in women than men. Consequently, compare to men, women have biological advantages in terms of effective immune mechanism to sever diseases and aging process (Blue, 2008). Socio-economic and Behavioral Causes Besides biological factors, socio-economic and behavioral factors play a crucial role in lifespan gap among both sexes. According to many researchers, male mortality patterns are often influenced by the male sex hormone, testosterone. As testosterone hormone has been linked with libido, competitiveness, and puberty, some experts link the male mortality from accidents, risky behaviors, violence, daredevil acts, and unhealthy habits to ‘testosterone toxicity’ (Perls & Fretts, 1998). According to majority of researches, the mortality margin between the unmarried and the married has been larger for men than that for women. This is referred to unmarried men’s unhealthy and risky lifestyles and dangerous activities and relatively healthier and safer lifestyle of women of all marital statuses (Scientific American, 2004). Also, women usually tend to show more religious participation than men. Involvement in religious activities is noted with lower levels of substance abuse, addiction, and more pervasive and positive social connections (Rogers et al., 2010, p. 557-558). Also, women show active social integration and family ties that provides them required emotional, instrumental, and social support. Compare to women, men are more susceptible to psychological problems like, depression and suicidal thoughts due to poor social lifestyle (Rogers et al., 2010, p. 557-559). Also, compare to women, men are more likely to be engaged in unhealthy and risky lifestyle such as, illegal drug use, drunken driving, violence, unhealthy eating habits, and other life-threatening acts (Lemaire, 2000, p. 2-5). Besides it, the greater involvement of men in the labor forces and risky jobs make them more prone to occupational hazards, reducing the overall lifespan of men (Lemaire, 2000, p. 5-7). Survival of the Fittest Many researchers and exports acknowledge the reasoning of Darwinian theory in explanation of human longevity and aging. Gender gaps in lifespan have been examined in other animal species too, and in fact, in almost all observed animal species, females possess greater life-expectancy than males. For example, female sperm whales live an average of 30 years longer than males, while female macaques surpass their male counterparts in longevity by an average 8 years. It is found that a species’ longevity is approximately related with the length of period that its offspring remain dependent on their parents (Perls & Fretts, 1998). Consequently, when long-term contribution of energy is needed to ensure the survival of young, evolution favors lifespan longevity, especially female longevity as females are more involved in nourishing and well-being of young-ones (Perls & Fretts, 1998). Conclusion In conclusion, there are many theories and assumptions about the potential causes of greater life-expectancy among females than males. However, majority of researches and studies have highlighted specific biological, behavioral and socio-economic factors that are closely associated with the greater longevity of women. Sex hormones such as, testosterone and estrogen, genetic factors, level of CRP, menstruation and menopause process, role in reproduction, social roles and duties, physical and psychological health, lifestyle, and habits are vital attributes in determining the longevity and ageing process. However, there is still scope for further research and studies to investigate further reliable and strong evidences that would determine the causes of greater life-expectancy among females than males. References Barford, A., Dorling, D., Smith, G. D., & Shaw, M. (2006). ‘Life expectancy: women now on top everywhere’. British Medical Journal (BMJ), vol. 332, no. 7545, p. 808. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1432200/?report=classic Blue, L. (2008, August 6). Why do women live longer than men? Time. Retrieved from http://content.time.com/time/health/article/0,8599,1827162,00.html Hope, J. (2014). Why women live longer than men. Daily Mail. Retrieved from http://www.dailymail.co.uk/health/article-72255/Why-women-live-longer-men.html Lemaire, J. (2000, November 13). Why do females live longer than males? www.actuaries.org, pp. 1-20, PDF document. Retrieved from http://www.actuaries.org/ASTIN/Colloquia/Washington/Lemaire.pdf Perls, T. & Fretts, R. (1998). Why women live longer than men. www.cmu.edu. Retrieved from https://www.cmu.edu/CSR/case_studies/women_live_longer.html Rogers, R. G., Everett, B. G., Saint Onge, J. M., & Krueger, P. M. (2010). ‘Social, behavioral, and biological factors, and sex differences in mortality’. Demography, vol. 47, no. 3, pp. 555-578. Retrieved from http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3000060/?report=classic Scientific American (2004, August 30). Why is life expectancy longer for women than it is for men? Scientific American- A Division of Nature America. Retrieved from http://www.scientificamerican.com/article/why-is-life-expectancy-lo/ Read More