Why has life expectancy increased in developed countries?

Answer 1

A variety of reasons could explain this. As medical technology advances, people live longer. Drugs and medications are created to help fight illness which further increases health. More knowledge is known on how to live longer and healthier as well. A lot just has to do with advances in technology.

AnswerThe #1 reason that people live longer in developer countries is something very simple: reliable, clean drinking water. The #2 reason is also very simple: very high levels of public hygiene, particularly good sewage systems and universal access to clothes and personal washing (i.e. clothes washers and showers). These two factors account for the vast majority of increased life expectancy vs the developing world. Well afterward is good nutrition in the pre-natal, infant, and childhood periods. Next would be almost universal vaccination to all common diseases. Next would be the significant increase in quality and timely access to trauma care (i.e. the ability to save people from common accidents). A very last on that list is the myriad of new drug treatments for various chronic conditions.

Here's the breakdown: a person in the developed countries lives about twice as long as one in the developing world (80+ years vs 40+). So, on average, a developed world person has a bit more than 30 additional years due to the above factors.

About 20 of those years are due to pure drinking water and good sewage. About 8 more are due to either better nutrition or universal vaccination. Another 2-3 or so come from better accident/emergency treatment (which includes common emergency illnesses, like appendicitis). Finally, maybe 1-2 comes from new drugs.

For the most part, new drugs DON'T increase life expectancy. However, they do significantly improve quality-of-life. This is due to most new drugs not curing things, but rather treating things. That is, most modern medicine is palliative, not curative.

Much of the reason behind this is economics: we're already discovered cures for those diseases which were cheapest to cure, and the research for cures for the remaining diseases is massively expensive and difficult. In addition, a treatment for a disease gives recurring revenue to the treatment creator (i.e. you get $$ per does of the treatment, for a potentially very large number of treatments), while curing a disease results in a single (or few) number of payments for the cure. Thus, the revenue stream for treatment is significantly better than cures. So, profit-driven companies look for treatments instead of cures, as it's a far better economic bet for the company.

Answer 2

That's mainly the result of reduced infant mortality. Only a relatively small part of the growth
in actuarial, statistical life expectancy is the result of prolonging life at the other end.