The Life Span of Early Man:
Until recently, little information existed about how long prehistoric people lived. Having access to too few fossilized humans remains made it difficult for historians to estimate the demographics of any population.
In an article published in 2011 in Scientific American, Caspari calls the shift the “evolution of grandparents,". It marks the first time in human history that three generations might have co-existed.
Ancient Through Pre-Industrial Times:
Life expectancy estimates that describe the population as a whole also suffer from a lack of reliable evidence gathered from these periods.
The average life spans in ancient Greek and Roman times as short at approximately 20 to 35 years, though he laments these numbers are based on “notoriously unrepresentative” graveyard epitaphs and samples.3
Moving forward along the historic timeline, Finch lists the challenges of deducing historic life spans. It causes death in this information vacuum.
As a kind of research compromise, he and other evolution experts suggest a reasonable comparison. It can be made with demographic data from pre-industrial Sweden (mid-18th century). It is certainly contemporary, small, hunter-gatherer societies in countries like Venezuela and Brazil.
Finch writes that judging by this data the main causes of death during these early centuries would most certainly have been infections. It could be whether from infectious diseases or infected wounds resulting from accidents or fighting
From the 1800s to Today:
From the 1500s onward, till around the year 1800, life expectancy throughout Europe hovered between 30 and 40 years of age.
Since the early 1800s, Finch writes that life expectancy at birth has doubled in a period of only 10 or so generations. Improved health care, sanitation, immunizations, access to clean running water, and better nutrition are all credited with the massive increase.3
Though it’s hard to imagine, doctors only began regularly washing their hands before surgery in the mid-1800s. A better understanding of hygiene and the transmission of microbes has since contributed substantially to public health.
The disease was still common, however, and impacted life expectancy. Parasites, typhoid, and infections like rheumatic fever and scarlet fever were all common during the 1800s.
Even as recently as 1921, countries like Canada still had an infant mortality rate of about 10%, meaning 1 out of every 10 babies did not survive. According to Statistics Canada, this meant a life expectancy or average survival rate in that country that was higher at age 1 than at birth—a condition that persisted right until the early 1980s.
In the Future:
Epidemiologists and gerontologists such as S. Jay Olshansky warn that in the United States. It is where two-thirds of the population is overweight or obese—obesity and its complications. Diabetes could very well reduce life expectancy at all ages in the first half of the 21st century.
In the meantime, rising life expectancy in the West brings both good and bad news. It’s nice to be living longer, but you are now more vulnerable to the types of illnesses that hit as you get older. These age-related diseases include coronary artery disease, certain cancers, diabetes, and dementia.
While they can affect the quantity and quality of life, many of these conditions can be prevented. At least delayed through healthy lifestyle choices like following an anti-aging diet, maintaining a healthy weight, exercising regularly, and keeping stress hormones like cortisol at bay.