Life expectancy: More complex than genetics

Men vs Women

Historically, and globally, women enjoy longer lives than men. Since the early 1980s, this gap has been closing in the UK and many other developed countries, where male life expectancy has been nearing women’s since the 1980s. But, in some countries, this gap is no longer closing. And in some countries it’s widening.

So…

• What affects life expectancy?
• Why do women live longer?
• Why has the gender gap stopped closing in some countries?
• And why is it growing in others?
• Finally, what can you do to ensure a long and healthy life?

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Around the world

In China, data shows that — while life expectancy is growing — the life expectancy gender gap is in fact widening, having closed in the early 1980s. Russia witnessed a similar convergence in the 1990s with the gap growing again in the recent years. India has seen women overtake men, expecting longer lives since the late 1970s, but as Indians enjoyed longer life expectancy, men’s grew slower than women’s and a gap emerged.

In 2008, American women’s life expectancy dropped for the first time since 1918. This is thought to be caused by the effects of smoking and obesity. Figures from 1989 to 2009 show the life expectancy of US males grew by 4.6 years while lifespans for American women rose by 2.7 years, but women can still expect to live for six more years than men (76.2 years versus 81.3 years). 2016 figures indicate that this gap is still closing as men catch up on their female counterparts.

Having enjoyed longer lifespans since the 1960s, in 2016, US life expectancy fell due — in part — to an explosion of drug overdoses (up 21% in 2016).

African countries have also enjoyed a surge in life expectancy, between 20-42% since 2000, and the gender gap remains low.

The numbers

Lowest life expectancy

• 183) Sierra Leone – M49 | F50 | Gap1
• 182) Angola – M51 | F54 | Gap3
• 181) Central African Republic – M51 | F54 | Gap3
• 180) Chad – M51.7 | F54.5 | Gap3
• 179) Cote D’Ivoire – M52 | F54.4 | Gap2.4

Mid-table nations’ life expectancy

• 84) Jordan – M72.6 | F76 | Gap3.5
• 80) Bulgaria – M71 | F78 | Gap7
• 70) Thailand – M72 | F78 | Gap6
• 67) Brazil – M71.4 | F79 | Gap7.6
• 62) Iran – M74.5 | F76.5 | Gap2

Highest life expectancy

• 1) Japan – M80.5 | F87 | Gap6.5
• 2) Switzerland – M81 | F85 | Gap4
• 3) Singapore – M80 | F86 | Gap5
• 4) Australia – M81 | F85 | Gap4
• 5) Spain – M80 | F85.5 | Gap5.5

Sources: J Bradford DeLong ‘Estimating World GDP, One Million BC-Present cited on Kruse Kronicle; Wikipedia.com

1818 – James Blundell performs the first successful transfusion of human blood

1857 – Louis Pasteur identifies germs as cause of disease

1867 – Joseph Lister develops the use of antiseptic surgical methods

1879-1897 – Vaccines developed for cholera, anthrax, rabies, bubonic plague and typhoid

1943 – Selman A. Waksman discovers the antibiotic streptomycin

1953 – James Watson and Francis Crick work on the structure of the DNA molecule

1978 – First test-tube baby is born

1996 – Dolly the sheep becomes the first clone

Compare these developments to the rise in life expectancy.

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The late rise of developing nations is often explained by the costs of medicine and technology being reduced over time — filtering down to ‘poorer’ countries later.

Specific examples show how the effect of governments (often aided by external donors such as the Bill & Melinda Gates Foundation), have been able to improve African health systems and the wellbeing — from medicines to education.

Yvonne Mhango, sub-Saharan economist at Renaissance Capital and a native of Malawi, told the Financial Times: “When I was growing up in the 1980s and 1990s, HIV/Aids killed a lot of the working-age population. It hasn’t been eradicated but the introduction of antiretroviral [drugs] that are affordable and accessible to low-income people has helped to lengthen their lives. They are able to work and look after their families. That has made a big difference.”

Some conditions affect only men or only women, but both sexes have benefitted from most of the medical breakthroughs of the past 200 years.

The death of war

Despite regional wars still filling the news, the global death rate from war fell from 22 per 100,000 people in 1945 to 0.3 in 2011. This decrease affected mainly men, but they are not the only sex to suffer in war.

https://ourworldindata.org/war-and-peace/

Famine

Innovations in agriculture — from irrigation to mechanisation — combined with increased and proliferating knowledge of biology have reduced famine to a rarity, not a norm. Robert Lacey and Danny Danziger’s The Year 1000 describes an England in which famines killed thousands as frequently as every 7-10 years.

Once synonymous with famine, Ethiopia’s cereal production doubled between 2004 and 2014, giving them increased immunity from recent droughts. This rise corresponds with a rise in life expectancy from 55 to 64.5 — ten years in ten years.

This change has affected both sexes.

Health and health care

One of the biggest factors is lifestyle — changes made by individuals. Better sanitation, improved public health, refrigeration and vaccination combined with education plays a key role in expanding life expectancy. It’s not just having access to an improved diet, it’s knowing that it’s important, how to use it and why. The 20th century’s growing individualism in the West has fuelled an obsession with the self, and this has been a driver for understanding how to make oneself healthier. This has been further facilitated by the commercialisation of health and the internet — putting information at people’s fingertips.

This has led to improved diet, the rise of the gym and reduced alcohol intake and the decline of habits like smoking. This in turn has resulted in longer life.

While the gender differences may be genetic, we can maximise our own life expectancy by the choices we make in our life.

This graph shows the rise and fall of smoking in the US. Mirroring it — with a lag of some 20 years — is the lung cancer death rate showing smoking’s decline resulted in a decline of lung cancer. A perfect example of individuals affecting their own life expectancy.

Source: ourworldindata.org

This graph represents how regular physical exercise affects longevity. Those with sedentary lifestyles are far more at risk from related diseases and die earlier.

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Culture and education clearly play a role in longevity for both sexes as many studies reveal, with the more educated in societies enjoying longer lives. This is particularly evident in developing countries as taboos and superstition are replaced by modern medicine. The middle of the last century saw the governments of many Western nations roll out mass immunisation initiatives and lifespans have grown as a result. More recently, The Hindu Times reported that educating women was helping to reduce maternal and child mortality in Bangladesh.

Expat life expectancy

Expats are a complex issue. People who may fit into their national statistics then change their lifestyle — and therefore, their life expectancy. For example, moving from a peaceful European nation with access to a good diet and health care to a war-torn developing nation with poor health care and a limited diet. One study found that Dutch expats die 20 years younger on average.

It is important for those living away from home — many in less developed nations — to set themselves up for success in a new country: a healthy lifestyle and access to good health care. Read: Relocating internationally — the value of pre-trip planning.

Why do women live longer than men?

Various theories for this have been given through the many years it has been observed. One hypothesis suggests men worked themselves into an early grave through hard labour and more hazardous professions. This includes violence and higher consumption of tobacco and alcohol.

The University of Alabama conducted a study to investigate causes of this gender disparity. They found that women have a robust survival advantage over men, whereas men have a robust health advantage over women.

Culture

This common-sense theory has been refuted by the increased number of men in office-based jobs and more women in work. This major western cultural shift did not affect life expectancy.

And this is reflected across the world with huge disparity in cultures and lifestyles yielding similar results. As one Swedish study states:

“This [pattern of women outliving men] is seen in every country in every year for which reliable birth and death records exist. There may be no more robust pattern in human biology.”

Evolution

Evolutionary theory suggests that women live so long past reproductive age (rare in the animal kingdom) because of the benefits to primitive human and proto-human societies: offering childcare to the youngest generation allowing parents to hunt and gather, as well as the usefulness of knowledge to early human cultures. In our evolutionary past, men’s usefulness is diminished when they are unable to hunt.

This may play a role in why female chimpanzees, gorillas, orangutans and gibbons also consistently outlive males.

In the genes

Some scientists have suggested that testosterone is the key. Korean scientist Han-Nam Parkcompared the ages of death of 81 19th-century eunuchs, whose testicles had been removed before puberty. He found that the eunuchs lived for an average of 20 years longer than other men. In fact they were 130 times more likely to reach 100.

David Gems at University College London found similar results for castrated patients in American sanitariums in the early 20th century — but only if they had been sterilised before the age of 15. So, while testosterone makes the male body stronger in the short-term it makes men more vulnerable to heart disease, infections and cancer later in life. Tom Kirkwood, from Newcastle University, UK, says: “The welfare of offspring is intimately connected with welfare of the maternal body. The bottom line is that it matters more for the children that the mother’s body should be in good shape, rather than the father’s.”

Experiments on animals show that females lacking oestrogen tend not to live so long. “If you remove a rodents’ ovaries,” says Kirkwood, “then the cells don’t repair against molecular damage quite as well.”

The female sex hormone oestrogen is an antioxidant, helping to combat poisonous chemicals that cause cells stress.

How long can we live?

Harari’s Homo Deus explores the next steps for humans. With the battle against disease and famine all but won, is the next goal immortality?

While immortality itself might be out of reach, life expectancy is still going up, and, as Professor Majid Ezzati, from the School of Public Health at Imperial College states: “We repeatedly hear that improvements in human longevity are about to come to an end. Many people used to believe that 90 years is the upper limit for life expectancy, but this research suggests we will break the 90-year-barrier. I don’t believe we’re anywhere near the upper limit of life expectancy — if there even is one.”

In 2017, the World Health Organisation predicted another increase in life expectancy in 35 industrialised countries by 2030. They predict that life expectancy in South Korea will reach 90.

Tips for a longer life

We’re not just prisoners of our DNA. We can influence how long we live — and how healthy that life is — by the decisions we make.

1. Don't smoke — find out more about how smoking damages your organs
2. Do physical activities every day
3. Eat a healthy diet — read: how to eat a healthy diet abroad
4. Maintain a healthy weight and body shape
5. Challenge your mind — read: 5 ways to safeguard your mental health
6. Follow preventive care and screening guidelines
7. Floss, brush, and see a dentist regularly
8. Ask your doctor if medication can help you control the potential long-term side effects of chronic conditions such as high blood pressure, osteoporosis, or high cholesterol.

What does the future hold?

Global health care costs are rising rapidly as populations age, not least because subsequent chronic conditions become more prevalent and demand for health care services outpaces supply. Consumers, employers and brokers are bearing the brunt of this rise through increased health insurance premiums and out-of-pocket costs. This is exacerbated by international disparities in the health care systems making quality care harder to access for many.

At Aetna International, we take a two-pronged approach:

• raising awareness of critical health challenges facing the world; and
• promoting effective, value-based care solutions that could help others combat and prevent the worsening of some of the world’s most serious health care problems.

With more than 1.2 million medical providers in the US and more than 165,000 outside it, 19 offices around the world and 160-year heritage, we’re a health care benefits partner with a global footprint who understands health care at a regional level. We understand that a healthy individual is a productive individual. Productivity makes people happy by enabling them to be socially, spiritually, economically and physically fulfilled.

For more information on international health care for you and your family, contact one of our expert sales consultants.

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