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The Conundrum of Life Expectancies and Life Spans

Updated: Oct 12, 2023

Written by Alexander P. (KIS ‘23)

━━ Nov 23rd,2020 ━━


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Have you ever thought of “when will I die” or “Why might I die?”. I sometimes just wonder what death is, as we have no scientific research of what happens after death. Moreover, many people tend not to think about the “ending” due to their fears despite all humans being aware that they would die at some point in their lives.

Human beings despite being the longest living primates are a mortal species where each and every human being would face death, whether that time is 10 years away or 100 years away. The inevitable concept of death hasn’t been much thought of but was just accepted as an assured end of human beings. The term to describe how long an individual life is referred to as the lifespan and the term life expectancies refers to the number of years a person can expect to live. Yet, there is a conundrum where this inevitable death strikes individual lives in different times and moments, thus this phenomenon makes a difference in the lifespan and life expectancies of individuals. So what is this factor that ultimately changes the life expectancies of different individuals and groups of people?


Group Life Expectancies


When I look at some statistics showing the world’s life expectancy by region, I always wonder why those living in places like Ethiopia or South Africa tend to have a shorter life expectancy than those living in Japan. Some individuals may be aware that sanitation and the environment one is in drastically affects the life expectancies of individuals. According to the Proceedings of the National Academy of Sciences (PNAS), the lifespan of human beings has doubled again in the 1800s, with improvements in the environment, food, and medicine that minimized mortality at earlier ages.

Democratic researches suggested that during the 19th century, no country in the world had a life expectancy higher than 40 years old as most countries in the world lived in extreme poverty with very little known medical knowledge. During the next 150 years from the 19th century is what started to divide the life expectancy of different groups and countries. Nevertheless, the average life expectancy of 2019 according to the United Nations was 72.6 years which is still higher than the longest expected life expectancy during the 1950s, Norway with 72.3 years.

Yet, in the current world, there are still inequalities within the life expectancies with different countries as poor countries: the Central African Republic had a life expectancy of 53 years in 2019 whereas higher-income countries like Japan have a life expectancy of 30 years higher. According to an experiment obtained by BMC HEALTH in 2018, the results showed that factors such as the mean years of schooling, total fertility rate, physician density, gross national income per capita, health expenditure, economic freedom, carbon dioxide emission rate, freedom of the press, corruption perceptions index and prison population all correlated to the life expectancies of regions. The experiment held different factors for the independent variable such as years in school, prison population, individual freedom, access to sanitation and water sources, etc. Thus, the experiment utilized statistical analysis to describe the situations and findings in the experimental regions. Thus from the experiment held, concluded that for lower and middle-income countries to increase their life expectancies, they must lower the fertility rates, and increase the mean years of schooling, freedom of the press.

As acquired from the experiment, many demographic variables, socioeconomic status, social structural indicators, health-related factors, and environmental issues had significant effects on the life expectancies of countries. It may seem that once these issues are analyzed, it would be easy to just go and resolve these factors and make it fitter to improve the life expectancy as a whole. However, the reason these low-middle income countries are somewhat stagnant when it comes to the increase of life expectancy is due to their marginal income and poor conditions to actually have spare time and resources to care about factors that affect life expectancy.

However, I believe that we should instigate some ideas and solutions which may help increase the life expectancy for lower-income regions as well. Life expectancy is a topic that was studied only for a short period of time mainly researched only from the 20th century. Thus, focused scientific research should take place in the near future to further help solve this inequality issue of life expectancies and try to help bring up the life expectancies for countries that are stagnant.


Individual Life Expectancies


Not only do factors affect the country's life expectancy as a whole. When I look at my past ancestors and relatives, some individuals lived longer than others despite all living in the same region. For instance, some of my relatives lived well past 80 whereas some passed away earlier. The point is, individual choices can also affect the lifespan as well. The ONS (Office For National Statistics) has taken data from the Public Health England and Annual population survey to analyze what impacts had an effect on individual peoples lifespan England. Many different habits turned out to have a general impact on the lifespan of a population.

One of these habits that drastically affect the life spans of individuals is the habit of smoking. According to the ONS, one in six deaths were linked to smoking with 480,000 deaths annually due to smoking. So why is smoking so lethal to the human body? Cigarettes or Cigars are composed of a substance known as tobacco which is obtained from a type of plant. Thus this continuous intake of tobacco can damage one’s heart and blood vessels, specifically the cardiovascular system. According to statistics from NIH (National Institute on Drug Abuse), the intake of tobacco, which includes nicotine, can immediately stimulate the adrenal glands to release the hormone epinephrine (adrenaline). Thus, this stimulates the central nervous system, increasing blood pressure, breathing, and heart rate; further being lethal in the long term run. Not only that but smoking can lead to lung cancer, chronic bronchitis (Inflammation of the Bronchial tubes which carry air from the air sac to the lungs; which can cause irritation and mucus to build up), and emphysema (a condition that causes shortness of breath as the air sacs (alveoli) are damaged). Moreover, smoking is correlated to the increase in the risk of heart disease, which can lead to stroke or heart attack. Smoking has also been linked to other cancers, leukemia, cataracts, Type 2 Diabetes, and pneumonia. Overall, smoking was known as a primary habit that divides those individuals who live 10 years shorter than nonsmokers.

Not only smoking, but another factor that affects individual life span is the diets individuals choose. Eating is a necessity for us human beings, yet, the division of those who live longer than another group is brought by what their diet consists of. Primarily, according to the Jackson Laboratory, research dating back to 1930 conducted by C. M. McCay, Mary F. Crowell, and L. A. Maynard, using rats and inbred mice, found that there was a correlation between restricting the number of calories consumed with the extended life span. Thus, what you intake also significantly affected the lifespan of individuals. Many different diets take place including keto, paleo, vegan and etc. However, the Mediterranean diet is a key example of a diet that extended life expectancies compared to many other choices of food. The Mediterranean diet is a diet that was in general, a diet high in vegetables, fruits, legumes, nuts, beans, cereals, grains, fish, and unsaturated fats such as olive oil. It usually includes a low intake of meat and dairy foods. Found by NHS, the Mediterranean diet decreased the risk of death by any cause by a staggering 14%. Moreover, in the current world, many more individuals are investigating diets that may reduce or increase life spans: information such as how excessive saturated fats can build up too much cholesterol, increasing the chance of stroke or heart attacks (MedlinePlus). Moreover, according to the ONS, individuals who had a better diet in Rutland lived an overall 13 years longer than those of Liverpool who had a less ideal diet.

Lastly, another obvious factor that affects an individual's lifespan is physical activity. The appropriate recommendation for moderate physical activity is 150 minutes every week. Thus, according to research done by C. D. Reimers, G. Knapp, A. K. Reimers, physical activity reduces many major mortality risk factors including arterial hypertension, diabetes mellitus type 2, dyslipidemia, coronary heart disease, stroke, and cancer. Moreover, all-cause mortality is decreased by about 30% to 35% in physically active as compared to inactive subjects. With regular physical activity, the research found that human lifespan increases around 0.4 to 4.2 years only from physical activity.


So What Now?


Many individuals are aware of the concept of life expectancies and understand that human beings will die one day. However, not many people are aware that human lifestyle and habits can drastically alter one’s lifespan. The following article I created discussing the possible factors that can affect human life expectancies aims to be a kick-off for what's to come on further research of life expectancies. The human species’ have been around for around 200,000 years. During our presentation, we have generally increased our life spans gradually. Through the time period of 2000- 2016, global life expectancy increased by 5.5 years. I believe that the topic of life expectancy isn’t focused so much on compared to other scientific fields such as computer sciences, and it is time that the fields of life expectancy should be accentuated. Therefore, with further research and development, I am confident this linear trend in life expectancy can continue.


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Credits:

“Facts about Saturated Fats: MedlinePlus Medical Encyclopedia.” MedlinePlus, U.S. National Library of Medicine, medlineplus.gov/ency/patientinstructions/000838.htm.


Finch, Caleb E. “Evolution of the Human Lifespan and Diseases of Aging: Roles of Infection, Inflammation, and Nutrition.” PNAS, National Academy of Sciences, 26 Jan. 2010, www.pnas.org/content/107/suppl_1/1718.


Islam MS, Mondal MNI, Tareque MI, et al. Correlates of healthy life expectancy in low- and lower-middle-income countries. BMC Public Health. 2018;18(1):476. Published 2018 Apr 11. https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-018-5377-x


National Institute on Drug Abuse. “Cigarettes and Other Tobacco Products DrugFacts.” National Institute on Drug Abuse, 24 July 2020, www.drugabuse.gov/publications/drugfacts/cigarettes-other-tobacco-products.


Peterson, Joyce Dall'Acqua. “Exploring the Diet-Life Span Connection.” The Jackson Laboratory, www.jax.org/news-and-insights/2017/november/diet-and-longevity.


Reimers, C D, et al. “Does Physical Activity Increase Life Expectancy? A Review of the Literature.” Journal of Aging Research, Hindawi Publishing Corporation, 2012, www.ncbi.nlm.nih.gov/pmc/articles/PMC3395188/.


Roser, Max, et al. “Life Expectancy.” Our World in Data, 23 May 2013, https://ourworldindata.org/life-expectancy


“Tier 1-Life Expectancy and Wellbeing-1.19 Life Expectancy at Birth.” Department of Health | Tier 1-Life Expectancy and Wellbeing-1.19 Life Expectancy at Birth, www1.health.gov.au/internet/publications/publishing.nsf/Content/oatsih-hpf-2012-toc~tier1~life-exp-wellb~119.


“What Affects an Area's Healthy Life Expectancy?” What Affects an Area's Healthy Life Expectancy? - Office for National Statistics, Office for National Statistics, 28 June 2017, https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/healthandlifeexpectancies/articles/whataffectsanareashealthylifeexpectancy/2017-06-28


#spectra#spectrapublications #lifeexpectancies #life #death




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