Since the middle of the XX, life expectancy at birth has risen on average by 3 months a year in Francee century, from 66 years in 1950 to 82 years in 2018. However, progress has slowed in recent years: life expectancy has risen on average since just one and a half months a year. one month a year for women.
Where does this delay come from? Is it cyclical or is it a new underlying trend? Should we expect a decline in life expectancy in a few years' time, as in the United States?
The effect of influenza epidemics
Seasonal influenza epidemics have been particularly fatal in recent winters: since 2014, three of them have been characterized by excessive mortality of around 15,000 deaths from influenza, each time, mainly among the elderly.
Seasonal flu epidemics, however, are not new. When they are deadly like those of recent years, they reduce life expectancy at birth from the year from 0.1 to 0.3 years, but the effect is cyclical, without affecting the underlying trend. The effect of influenza epidemics appears to be delayed by other causes. To understand the situation, it is useful to place recent developments in the context of changes in the longer term.
The huge growth in life expectancy since the middle of the XXe century – it has increased by 16 since 1950 – is mainly due to successes in the fight against adult mortality, especially in the high ages in which more and more deaths are concentrated. Infant mortality has reached levels so low in recent decades that its evolution has little impact on life expectancy at birth.
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Cancer the first cause of death in cardiovascular disease
In the middle of the XXe In the last century, infectious diseases were still the cause of a large number of deaths among adults and the elderly, and their decline has led to a significant increase in adult life expectancy. But the share of these diseases in total mortality has fallen considerably and the profits that must be made with the continuation of their decline are low.
Cardiovascular diseases and cancer are now the leading causes of death. And it is the successes in the fight against these diseases that have made it possible for life expectancy to continue to rise in recent decades (figure opposite).
Mortality due to cardiovascular disease has decreased considerably in the last half century, thanks to the & # 39; cardiovascular revolution & # 39; progress in prevention and treatment in this area. With regard to cancer mortality, which had increased, it is now decreasing thanks to earlier diagnoses, improved treatments and the reduction of risky behaviors such as smoking.
The delayed effects of smoking on death
The slower progress of life expectancy over the past decade may be a sign that the benefits of the cardiovascular revolution have run out. And future progress may increasingly depend on the fight against cancers that have become the leading cause of death. If successful, the benefits in terms of life expectancy so far have been less spectacular than those related to the cardiovascular revolution.
Cancer mortality has decreased significantly in men and continues to decline. In women, where it is lower than men, it has slowed down and even stopped in recent years. One of the reasons is the rise of smoking in the 1950s to 1980s in the generations of women 50 or older today. They suffer the consequences a few decades later, in the form of an increase in cancer related to tobacco.
French women still well placed in Europe
A similar delay in life expectancy is observed in the countries of Northern and Western Europe (figure below). Just as in France, it is more pronounced among women than among men. The delay is old among the Swedes. While the latter enjoyed one of the highest life expectancies in Europe in 1980, they were caught and then defeated by the French, Spaniards, and Italians who took the lead.
The reason that women in the Nordic countries experienced the delay earlier than the others is partly because they started smoking earlier and therefore had more consequences in terms of increased child labor. death from tobacco-related cancers.
With more than 87 years of life expectancy, the Japanese today hold the record. They show that margins of progress still exist before limits are reached. The French, in turn, are still poorly located, despite their strong growth.
The United States is increasingly distancing itself
In the United States, progress in life expectancy has not only slowed down, but in recent years has made way for both men and women to fall. Here too there is an increase in tobacco-related mortality. In addition, there are various health problems, such as the frequency of obesity and an epidemic of deaths from overdose with opioids in adults. Another aggravating factor is that the health system in the United States is uneven, making it difficult for poor people to gain access to care.
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While life expectancy in the United States reached one of the highest levels in the world, this country was overtaken and then doubled by many other developed countries. It is now being further removed, especially by European countries. In 1980 the life expectancy of men was identical in the United States and France. The benefit of the French women was then no more than 1 year compared to the Americans; in 2017, the life expectancy of the latter is more than 4 years behind that of French women, and the gap has been on the men's side for more than 3 years.
It is not at all certain that Europe, and in particular France, will in turn be affected by a fall in life expectancy, as their health systems are more protective and more even than those of the United States. However, in order to further increase life expectancy in France in the coming years, cancer-related mortality in men must continue to fall and decrease again in women.
In the longer term, the benefits of advances in the fight against cardiovascular disease and cancer will eventually be exhausted, as was the case with advances in the fight against infections. New battlefields, such as neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, etc.) and medical and social innovations can then take over the task and open a new phase of health progress. Which could not lead to immortality, old dream inaccessible, but delayed the calculation of a life expectancy progression.
This text is based on the article "Why does life expectancy in France increase less rapidly? Published in nr. 564 of Population and Societies.