As transhumanists in the developed world dream of curing or preventing heart and lung disease, the developing world will finally start living long enough to die from them.
The US Census Bureau's An Aging World: 2015 report suggests that the global population older than 65 will double between 2025 and 2050, but notes that a "distinct feature of global population aging is its uneven speed across world regions and development levels."
While life expectancies will continue to get better around the world, those in the developing world will merely increase to be closer to what the developed world already has today. The good news, I guess, is that people in developing countries are dying from infectious diseases less often and are finally dying from regular ol' things like cancer, heart attacks, diabetes, and strokes that tend to affect people at older ages. The bad news is that advanced medical technology isn't reaching these people fast enough to treat these diseases.
The question as to 'whether or not limits to human life span exist' are key to humanity's future
"Deaths and disability from noncommunicable diseases are rapidly rising in less developed countries," the report notes, "and yielding worse outcomes than in more developed countries; some diseases that are preventable or treatable in more developed countries are leading to deaths in less developed countries."
This means that people in wealthy countries will continue to live longer, while people living in Africa will see their life expectancies extend more slowly, especially when they reach older ages. Take two women who turn 65 on January 1, 2050. Statistically, one who is born in Afghanistan will be able to expect to live about to age 80, while one born in Singapore can expect to live to age 95, according to the Census Bureau's projections, which are based on current aging trends and fertility statistics, health care availability and quality, and general population stats.
Given what we know about how access to modern medicine and basic access to things like food, water, medicine, and plumbing, affects mortality rates, it's not shocking that countries that currently have high life expectancies will continue to have the longest lives in the future.
What's clear from the report, though, is that while developing countries will begin to have longer life expectancies, they won't close the gap with developed countries, because doing so would require eliminating infectious disease, expanding basic services and infrastructure that affect life expectancy, solving income inequality worldwide, and finally making modern medical techniques broadly available.
"Life expectancy at different ages for men and women points to considerable heterogeneity and plasticity of aging processes, but also extreme variation and persistent inequality," the bureau wrote. "The very same factors correlated with the dramatic drops in mortality in Western Europe and North America at the beginning of the 1900s, namely water, sanitation, and diet still contribute to mortality rates across many other regions—although with considerable and ongoing progress."
Interestingly, the Census Bureau report wonders openly if there's a limit to how long humans can live. Though the bureau never uses the word "transhumanism," it says that the question as to "whether or not limits to human life span exist" and "whether healthy life expectancy will keep pace with increasing average life expectancy" are key to humanity's future, which are two of the main goals of the transhumanist movement.
As the developed world wonders whether or not humans can live forever, the developing world will have to decide how it will deal with dementia, heart disease, stroke, lung disease, cancer, diabetes, and other ailments that tend to come as noncommunicable diseases start to kill more people than infectious disease.
With history as a guide, there are two main tacks to take (with the ideal being a mix of both, of course). Heart disease, stroke, lung disease, and diabetes—among the most common causes of death in developed nations—are also the "most burdensome conditions" leading to disability at older ages. Broadly speaking, you can delay the onset of these diseases or you can treat them as they come.
A 65-year-old in Norway, which has a generally healthy population for example, can expect to live 16 more years "without activity limitations," while a 65-year-old in Slovakia, which has a generally less healthy population, can expect disability to set in around age 68, according to the Census Bureau.
The data suggests that the developing world should focus more energy on delaying the onset of these diseases with robust antismoking, active lifestyle, and healthy eating campaigns (or at least a focus on achieving the economic equality that enables these lifestyle choices). Time and time again, we've seen that countries with a generally healthy younger population tend to have generally healthy older populations.
This is because we've already found that treating these chronic conditions as a first line of defense doesn't really work. A landmark 2011 review by the National Academy of Sciences found that the United States's life expectancies and healthy life expectancies were falling behind that of the rest of the world despite the fact that the US "spends far more on health care than any other nation in the world."
The paper found that high smoking rates, as well as "obesity, diet, exercise, and economic inequality, also have likely played a role in the current gap [in life expectancy] and divergence between the United States and other countries."
There are surely roles for advanced medicine and advanced technology to play in extending the average useful life of a human, but, in the near-term, the future of longevity for the human race may lie in making sure people in the developing world have access to basic human needs.