Lifespan or Maximum Lifespan is referred to as the greatest age reached by any member of a given population (or species). For humans, the lifespan is currently between 120 and 125. Life expectancy is defined as the average number of years that members of a population (or species) live. Pre-COVID-19, the World Health Organization (WHO) (2019) reported that the global life expectancy for those born in 2019 was 72.0 years, with females reaching 74.2 years and males reaching 69.8 years. Women lived longer than men around the world, and this gap has remained the same since 1990. Life expectancy ranged from 61.2 years in the WHO African Region to 77.5 years in the WHO European Region. Overall, global life expectancy increased by 5.5 years between 2000 and 2016. Improvements in child survival and access to antiretroviral medication for the treatment of HIV were considered factors for the increase. However, life expectancy in low-income countries (62.7 years) was 18.1 years lower than in high-income countries (80.8 years). In high-income countries, the majority of people who died were old, while in low-income countries almost one in three deaths were in children under 5 years of age.
COVID-19 and World Life Expectancy:
According to a recent WHO report (2022) current estimates indicate that the COVID-19 pandemic is either slowing or reversing the rising trend for life expectancy in the world. The WHO report found that life expectancy in 2020 had fallen in all but three of 37 high income and upper middle income countries compared with 2019, with men experiencing a greater decline in life expectancy. The study estimated that more than 28 million excess years of life were lost in 2020 in those 37 countries.
Woolf et al. (2022) looked specifically at comparing 2020 life expectancy in the U.S. with 21 peer countries. While the 2020 U.S. life expectancy decreased 1.8 years from 2019 to 77 years, the average decrease in life expectancy among the comparison countries was only 0.58 years. No peer country experienced decreases as large as those seen in the U.S. The average life expectancy in the peer countries was 81.50 years, which was 4.5 years higher than the U.S. life expectancy. Outcomes in peer countries ranged from a decrease of 1.43 years in Spain to increases in life expectancies in New Zealand, South Korea, and Taiwan. In Denmark, Finland, and Norway, life expectancy did not change significantly. Given that COVID-19 mortality and excess deaths in the U.S. were among the highest in the world, it is not surprising that the decline in U.S. life expectancy exceeded the declines in other countries, Since 2010, U.S. life expectancy has remained stagnant, and even decreased for three consecutive years from 2014 to 2017. In contrast, life expectancy in other countries continued to increase resulting in a widening life expectancy gap with peer nations. This 2020 preliminary evidence proposes that the gap with other countries increased even further during the COVID-19 pandemic.
World Healthy Life Expectancy:
A better way to appreciate the diversity of people in late adulthood is to go beyond chronological age and examine how well the person is aging. Many in late adulthood enjoy better health and social well-being than average and would be aging at an optimal level. In contrast, others experience poor health and dependence to a greater extent than would be considered normal. When looking at large populations, the WHO (2019) measured how many equivalent years of full health on average a newborn baby is expected to have. This age considers current age-specific mortality, morbidity, and disability risks and is referred to asThe Healthy Life Expectancy. Figure \(\PageIndex{1}\) shows the differences in additional years of healthy aging among the WHO regions.
Figure \(\PageIndex{1}\). Healthy Life Expectancy after age 60 by WHO world region and gender, 2019.
In 2016, the global Healthy Life Expectancy was 63.3 years up from 58.5 years in 2000. The WHO African Region had the lowest Healthy Life Expectancy at 53.8 years, while the WHO Western Pacific Region had the highest at 68.9 years. Similar to overall life expectancy, current estimates from the WHO (2022) indicate that the COVID-19 pandemic is either slowing or reversing the rising trend for Healthy Life Expectancy. It is estimated that the Healthy Life Expectancy has fallen by up to one to two years in some countries and by smaller margins in several others.
COVID-19 and Life Expectancy in America:
COVID-19 has had a significant impact on life expectancy in the U.S. The overall life expectancy for a baby born in 2020 in the United States was 77 years, decreasing from 78.8 years in 2019 (Murphy et al., 2021). The decrease from 2019 occurred for both males, changing from 76.3 years in 2019 to 74.2 years in 2020, and females, changing from 81.4 years in 2019 to 79.9 years in 2020. The difference in life expectancy between the genders was 5.7 years in 2020, increasing from 5.1 in 2019. Figure 9.3 shows the United States life expectancy changes between 2000 and 2020 by gender.
Figure \(\PageIndex{2}\). Trends in U.S. life expectancy by gender between 2000 and 2020. Image source.
In 2020, life expectancy at age 65 for the total U.S. population was an additional 18.5 years, but this was a decrease of 1.1 years from 2019 (Murphy et al., 2021). For males, life expectancy at age 65 decreased 1.2 years from 18.2 in 2019 to 17.0 in 2020. For females, life expectancy at age 65 decreased 1.0 year from 20.8 in 2019 to 19.8 in 2020. The difference in life expectancy at age 65 between females and males increased 0.2 year, from 2.6 years in 2019 to 2.8 in 2020 . Figure 9.4 documents the changes in life expectancy between 2019 and 2020 for both genders at birth and at age 65.
Figure \(\PageIndex{3}\). U.S. life expectancy at birth and age 65, by gender: 2019 and 2020. Image source.
Ethnic Differences in Life Expectancy
Declines in U.S. life expectancy in 2020 varied greatly by race and ethnicity (Woolf et al., 2022). Life expectancy in the Hispanic population showed the largest decline as there was a decrease of 3.70 years from 81.86 years in 2019 to 78.16 years in 2020. The non-Hispanic Black population experienced a decrease of 3.22 years from 74.76 years in 2019 to 71.54 years in 2020. In contrast, life expectancy in the non-Hispanic White population decreased by 1.38 years. Using data from January 2020 through June 2020, Figure \(\PageIndex{4}\) shows the decreases in life expectancy based on the intersectionality of both gender and ethnicity.
Figure \(\PageIndex{4}\). U.S. life expectancy decreases from January to June 2020. Image source.
Although all the U.S. data for 2021 have not been verified, the hope was that widespread distribution of effective vaccines would reduce racial/ethnic disparities in 2021. Andrasfay and Goldman (2022) used estimates based on provisional COVID-19 deaths for 2021, and found that racial/ethnic disparities continued to persist in 2021. The corresponding reductions in life expectancy estimated for Black and Latino populations are 1.3–1.9 times that for Whites, suggesting smaller disparities than those in 2020, but still evident of overall racial/ethnic inequities in life expectancy.
Ethnic Disparity Causes:
Data indicate that the percent of Hispanic/Latino, non-Hispanic Black, non-Hispanic American Indian, and Alaska Native people who died from COVID-19 in 2020 was higher than the percent of these racial and ethnic groups among the total U.S. population (CDC, 2021). Several factors have been identified for their higher COVID-19 death rates including that these groups were disproportionately represented among essential workers, including working in health care, security, retail, farming, factories, warehouses, food processing, food service, construction, grocery stores, and transportation (Mahr, 2021). In contrast, people who were in jobs that enabled them to work remotely were less likely to become infected. Racial and ethnic minorities were also disproportionately represented in settings with higher COVID-19 outbreaks, including correctional facilities, homeless shelters, long-term care facilities, and living in multi-generational homes (CDC, 2021). Additionally, disparities in medical care and underlying health conditions such as diabetes, hypertension, and heart disease disproportionately affect minorities. Entrenched racial discrimination has been identified as a contributing factor to all the disparities. The COVID-19 pandemic demonstrates the need to promote the health and well-being of racial and ethnic minorities (Mayo Clinic, 2021).
Gender Differences in Life Expectancy
Biological Explanations:
Biological differences in sex chromosomes and different pattern of gene expression is theorized as one reason why females live longer (Chmielewski, Boryslawski, & Strzelec, 2016). Males are heterogametic (XY), whereas females are homogametic (XX) with respect to the sex chromosomes. Males can only express their X chromosome genes that come from the mother, while females have an advantage by selecting the "better" X chromosome from their mother or father, while inactivating the "worse" X chromosome. This process of selection for "better" genes is impossible in males and results in the greater genetic and developmental stability of females.
In terms of developmental biology, women are the "default" sex, which means that the creation of a male individual requires a sequence of events at a molecular level. According to Chmilewski et al. (2016):
These events are initiated by the activity of the SRY gene located on the Y chromosome. This activity and change in the direction of development results in a greater number of disturbances and developmental disorders, because the normal course of development requires many different factors and mechanisms, each of which must work properly and at a specific stage of the development. (p. 134)
Men are more likely to contract viral and bacterial infections, and their immunity at the cellular level decreases significantly faster with age. Although women are slightly more prone to autoimmune and inflammatory diseases, such as rheumatoid arthritis, the gradual deterioration of the immune system is slower in women (Caruso et al., 2013; Hirokawa et al., 2013).
Looking at the influence of hormones, estrogen levels in women appear to have a protective effect on their heart and circulatory systems (Viña et al., 2005). Estrogens also have antioxidant properties that protect against harmful effects of free radicals, which damage cell components, cause mutations, and are in part responsible for the aging process. Testosterone levels are higher in men than in women and are related to more frequent cardiovascular and immune disorders. The level of testosterone is also responsible, in part, for male behavioral patterns, including increased level of aggression and violence (Martin et al., 2011; Borysławski & Chmielewski, 2012). Another factor responsible for risky behavior is the frontal lobe of the brain. The frontal lobe, which controls judgment and consideration of an action's consequences, develops more slowly in boys and young men. This lack of judgment affects lifestyle choices, and consequently many more boys and men die by smoking, excessive drinking, accidents, drunk driving, and violence (Shmerling, 2016).
Lifestyle Factors:
Certainly not all the reasons women live longer than men are biological. As previously mentioned, male behavioral patterns and lifestyle play a significant role in the shorter lifespans for males. One significant factor is that males work in more dangerous jobs, including police, fire fighters, and construction, and they are more exposed to violence. According to the Federal Bureau of Investigation (2014) there were 11,961 homicides in the U.S. in 2014 (last year for full data), and of those 77% were males. Males are also more than three times as likely to commit suicide (CDC, 2016a). Further, males serve in the military in much larger numbers than females. According to the Department of Defense (2015), in 2014 83% of all officers in the Services (Navy, Army, Marine Corps and Air Force) were male, while 85% of all enlisted service members were male.
Figure \(\PageIndex{5}\). Men have more dangerous jobs. Image source.
Additionally, men are less likely than women to have health insurance, develop a regular relationship with a doctor, or seek treatment for a medical condition (Scott, 2015). As mentioned in the middle adulthood chapter, women are more religious than men, which is associated with healthier behaviors (Greenfield et al., 2009). Lastly, social contact is also important as loneliness is considered a health hazard. Nearly 20% of men over 50 have contact with their friends less than once a month, compared to only 12% of women who see friends that infrequently (Scott, 2015). Overall, men's lower life expectancy appears to be due to both biological and lifestyle factors.
Figure \(\PageIndex{6}\). Men benefit from a relationship with a doctor. Image source.
American Healthy Life Expectancy:
To determine the current United States Healthy Life Expectancy (HLE), factors were evaluated in 2019 to determine how long an individual currently at age 60 will continue to experience good health (WHO, 2022). An additional 16.4 years was average, with males having an additional 15.6 years and females an additional 17.1 years. Looking at the years 2007–2009, the highest HLE was observed in Hawaii with 16.2 years of continued good health (CDC, 2013). Overall, the lowest was among southern states. Females had a greater HLE than males at age 65 years in every state and DC. HLE was greater for whites than for blacks in DC and all states from which data were available, except in Nevada and New Mexico.
Children born in America today may be the first generation to have a shorter life span than their parents. Much of this decline has been attributed to the increase in sedentary lifestyle and obesity. Since 1980, the obesity rate for children between 2 and 19 years old has tripled, as 20.5% of children were obese in 2014 compared with 5% in 1980 (American Medical Association, 2016). Obesity in children is associated with many health problems, including high blood pressure, type 2 diabetes, elevated blood cholesterol levels, and psychological concerns including low self-esteem, negative body image and depression. Excess weight is associated with an earlier risk of obesity-related diseases and death. In 2007, former Surgeon General Richard Carmona stated, "Because of the increasing rates of obesity, unhealthy eating habits and physical inactivity, we may see the first generation that will be less healthy and have a shorter life expectancy than their parents" (p. 1).
