More people live longer as life expectancies grow over the decades. For example, in 1900, the worldwide average life expectancy (defined as the average number of years remaining) was 32 years. By 2024, it is now 73.3 years. A commonly-asked question is how much life is left for those of us aged 80 and above?
Leaving aside personal subjective guesses, the following are broad indicators of our life expectancy at age 80:
- Generally, an 80-year-old man in any affluent country has about 7 more years to live (Women have more – 9.1 years).
- Men have a 50% chance of living to age 83 (women have 50% chance of living up to 86 years). This is particularly so in Australia where the average life expectancy is 83.2 years.
- Most 80-year-old men have only a 30% chance of making it to their 90th birthday. But for women, it is a 50% chance, especially for women in Japan.
- Most 90-year-old have just about another 3-5 more years of life.
- A 92 or 93-year-old man has only an overall 6.0% chance of surviving to 100. For women, it is almost double that chance (11.4%).
- A 92-93-year-old man with an active mental state has 21.7% chance of surviving to 100; for a woman, her chances are 50% higher at 32.2%.
What has to be factored in are four main factors known to greatly influence our actual individual life expectancy, viz 1. Our genes; 2. The environment we live in; 3. Our life style, and, 4. Falling risks.
1. Our genes
A lucky few have good longevity genes from parents. In 2015, 4279 people in Australia were 100 years or older. That’s out of a total Australian population of 23.8 million at the time. However, studies suggest genetic factors account for only about 25% of one’s longevity. In other words, people with good longevity genes still depend on other factors for much of their actual longevity.
2. Our living environment
The living environment has a large influence on our longevity. This is shown in how people in affluent countries tend to live much longer (up to about 30 years) than people in poor countries. In other words, being 80 years old may be seen differently when account is taken of the country one lives in. Thus, whilst the average life span in Chad and in Nigeria is about 53.6 years (64.3 year in the African continent), it is about three decades more in affluent countries.
For example, it is 84.8 years in Japan, 82.9 years in Singapore, 83.2 years in Australia, 82.7 years in New Zealand, 82.6 years in South Korea, 82 years in the UK, 81.5 years in the European Union and 81.3 years in Canada. Somewhere in between are, for example, 78.5 years in China, 77.4 years in the US, 76.2 years in Malaysia, 71.2 in the Middle East and 67.7 years in India.
The effect of affluence is confirmed in research (led by epidemiology professor, Dr Paola Zaninotto at University College London) which found that being wealthy adds 9 years to a healthy life expectancy.
3. Healthy lifestyle
A healthy lifestyle can also increase average life expectancy by 7.6 years [6.5 years in women]. Indeed, a 2024 study published in JAMA shows living a healthy life style can help 80-year-old people reach 100.
Overall, 11 studies show regular physical exercise alone can increase life expectancy by 0.4 to 4.2 years, as for example, by having 150-300 minutes of aerobic exercise weekly. As found in a major UK study (The Biobank project), this is even for those with multiple medical conditions. However, the life expectancy gain for them is slightly less: 6.3 years in men and 7.6 years in women.
On the other hand, an unhealthy lifestyle is linked to obesity and a potentially shortened life expectancy. A 2022 report in Lancet shows obesity caused loss of life expectancy of nearly 2·4 years. Also, a National Cancer Institute study found extreme obesity can cost loss of up to 13.7 years of life expectancy. In contrast, Japan’s highest life expectancy in the world is linked to its low mortality rate of obesity (4.8% men; 3.7% women).
4. Falling risks
The elderly can die from bad falls, either immediately or not too long thereafter. Many old people fall because they falsely assume they are still as fit, agile and have as good a sense of balance as in their younger years. Unfortunately, falling once doubles chances of falling again. And quite rightly, falls also cause fear of more falls.
Statistics show about 27% of older people fall each year. In Australia, it is about 30%. The awful truth is that oldies cannot tolerate a fall and recover from trauma like a 20-year-old because they tend to be malnourished, their bones, muscles, and organs are all less effective and they also have weaker immune responses. For them, fall injuries can lead to home confinement with consequential loss of much essential mobility. In short, falling can shorten their life expectancy. One study found the average mortality rate for people who had more than one fall in three months was 16.4% compared to 8.5% for those who did suffer a fall.
To sum up, someone in his or her early 80s can live up to 90 [and even possibly 100 years] provided he or she is affluent, retains relatively good health, consistently has a physically active life, and takes extra care to avoid falls.
Gim Teh
Gim Teh is a retired Australian law academic and a former member of the Victorian Civil and Administrative Tribunal. He has an interest in misinformation and imperialism and has written about US-Australia-China relationship.
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