Is the significant rise in life expectancy finally slowing down? Why?

A new study of expected lifespans between 1990 and 2019 shows that the sharp increase in life expectancy over the past century is finally slowing down and will stop when the average life expectancy reaches 87.

Gerontologist Jay Olshansky and several other co-authors conducted the study, which was published last week in Nature Aging, and found that over the past 30 years, the rate of decline in life expectancy has slowed significantly.

It looked at data on life expectancy at birth collected between 1990 and 2019 from the eight countries with the highest life expectancies – Australia, France, Italy, Japan, South Korea, Spain, Sweden and Switzerland. Additionally, it looked at the lifespans of Americans and Hong Kong.

Prior to 1990, Olshansky, who is now professor of epidemiology and biostatistics at the University of Illinois in Chicago, conducted research that led to the new study. The world as a whole has an average life expectancy of 72 years.

In 1990, Olshansky claimed that there was only a certain distance medicine could travel before we would start to age and that the world was about to end. His most recent study provides stronger proof for this assertion.

Why has life expectancy increased so dramatically over the past ten years?

About 100 years ago, in the late 19th and early 20th centuries, the average life expectancy was approximately 50 years. By 1990, this had risen to about 70 – and was as high as the mid-80s in richer countries – following what researchers call a “longevity revolution”.

The first longevity revolution saw a dramatic increase in life expectancy for both men and women because women and children who had previously died early were now living to a “normal” age thanks to advances in medical care that prevented infant deaths and women’s deaths during childbirth.

“You can save children only once, and once you’ve done it, these children who ordinarily would have died at much younger ages, are now living much, much longer than would have been the case”, Olshanksy explained.

Since the end of the 20th century, the medical industry has turned its attention to diseases and disorders that have become more prolific because we are living longer, including heart disease, cancer, stroke and Alzheimer’s disease. Improved medicine is now allowing people to survive these conditions.

What is revealed by the new study?

The study looked at data collected between 1990 and 2019 regarding life expectancy. This year, the study purposefully stopped to remove any artificial dampening brought on by the COVID pandemic.

In some of the wealthier nations studied, the “upper average” life expectancy is already 85 for women and 82 for men, respectively.

According to the new study, some nations are already on the verge of reaching the maximum life expectancy, which is 84 for men and 90 for women. After that, however, the average age at death would stop rising.

The study’s focus was “life table entropy,” which suggests that there are limitations to the length of the longevity revolution.

“When you live out to these later and later ages, into your 70s, 80s, 90s, 100, you run into a problem”, says Olshansky. “That problem is the biological process of ageing itself, the ageing of our cells, tissues, organs, organ systems that we call senescence.

The rise in life expectancy must slow down when you push survival into a window where they are subject to an immanent force of biological ageing.

In the end, the study concluded that the only way to prolong life is to stop the process from happening right away.

Can we slow the ageing process?

Life expectancy will most likely increase as a result of advances in medical technology, but there is still a cap due to natural ageing. Therefore, the next step to continuing the” longevity revolution “is to slow the process of ageing itself, something Olshansky says he is” confident “could happen. It is undoubtedly something being studied.

According to the study, “There is reason to be optimistic that a second longevity revolution is on the verge of bringing about a second chance for humanity to alter the course of human survival,” given the rapid advancements that are currently taking place in geroscience.

Geroscience is the study of the biological process of ageing, in short, what makes our bodies age.

Researchers can also examine the underlying factors and environment that have affected their long lives, such as healthy centenarians (those over 100 years) and supercentenarians (those over 110 years).

Some people who live to be older may have a particular genetic signature, which might help answer the question of what causes longevity.

According to Olshanksy, there are likely to be specific genes in their bodies that make them resistant to the things that kill the rest of us when we are younger.

Other animals with long lifespans may gain insight from their studies. One of the reasons scientists are interested in studying other long-lived species is because of this. How is a 210-year-old bowhead whale able to survive? How is a Greenland shark able to live for 500 years? “he added.

What was the study’s research on individual nations?

Additionally, the study found results that were particular to each country. Although the cause of this discovery is still unknown, Hong Kong is seeing a stronger uptick in life expectancy than most nations.

According to the study, Hong Kong has the highest population-specific likelihood of surviving to 100, with 14.4% of males and 12.8% of females expected to reach 100 in their lifetimes, based on life tables starting in 2019.

The most recent World Bank data from 2022 shows that Hong Kong’s average life expectancy is 84 years, whereas the world averages 72 years.

A life table in the study displays the variation in a population’s chance of surviving or dying.

According to the study, smoking bans and economic prosperity that were implemented between 1990 and 2000 contributed to the increase in life expectancy in Hong Kong.

However, in all countries, including Hong Kong, China’s self-governing territory”, the most recent decade of change in life expectancy is slower than it was in the last decade of the 20th century”, the study concluded.

Of the 10 countries studied, the US showed the slowest improvement in life expectancy. According to 2022 World Bank data, the average life expectancy in the US is 77 years.

Why is life expectancy slowing in the US particularly?

Olshanksy attributes the lack of access to affordable healthcare to some of the slowing down in life expectancy in the US. The US operates an insurance-based system of healthcare, unlike the vast majority of Western countries, where healthcare is mostly funded by taxation and accessible by all. In the US, there is a sharp division between those who have access to high-quality healthcare and those who don’t. Due to disparities in quality healthcare, one subpopulation of the population is thus lowering the US’s overall average.

Source: Aljazeera