It's an article of faith among most 21st-century humans that life is getting longer. In the last three decades, the average life span at birth has increased from about 60 years to 67 years worldwide, a remarkable achievement.
But in two dozen countries, human life spans are shortening for one of the few times since the bubonic plague swept through Europe and elsewhere in the 14th century. One expert calls the situation a "shortgevity" crisis.
The greatest setback has been in sub-Saharan Africa, swept by the HIV/AIDS epidemic. In all, 10 African countries have seen projections for their average life span fall below 40 years of age. The good news is that in Russia and in some of its close neighbors, the decline seems to have been reversed. Such trends are key to future prosperity.
"We talk a lot about the inequality of wealth [between the developed and developing worlds], and it seems to me we don't talk enough about the inequality in length of life, because connected with that of course is education, vigor, productivity," says Robert Butler, founder and chief executive of the International Longevity Center in New York and professor of geriatrics at Mount Sinai Medical Center there.
The world should care about what he calls shortgevity for self-interested reasons, he adds. "If we really are serious about the concept of global trade, then we'll realize that those other nations have to be given a fighting chance to be productive as well. And if they're not, they are not going to have the money to buy all our wonderful products and exchange goods with us."
For Russians and other members of the former Soviet bloc, the situation looked bleak a few years ago. The fall of the Soviet state in 1991 left "a degree of disorder that was disadvantageous to health," says Kenneth Hill, a demographer and director of the population center at the school of public health at Johns Hopkins University in Baltimore.
While infant mortality didn't rise significantly, self-destructive behaviors by adults did, including alcoholism. A clear social structure, based on party loyalty, had collapsed, and nothing had replaced it.
"It wasn't so much that the healthcare system worsened, but that the people's general spirit worsened," Dr. Hill says. That feeling of helplessness was associated with high mortality. "There's some evidence that being depressed isn't just bad for your mental health, it's bad for your physical health as well," he says.
Today illicit drugs and alcoholism are still major social ills in the region. But the outlook has begun to improve as those countries stabilize socially and economically, though longevity rates have still not returned to their peak levels of the 1980s.
In sub-Saharan Africa, the picture remains alarming. Experts attribute much of the problem to the HIV/AIDS epidemic there, which accounts for 25 million of the 40 million cases of HIV/AIDS in the world. According to the latest United Nations Human Development Report, life expectancy in Zimbabwe plummeted from 56 years in 1970-75 to just 33.1 today. Zambia went from 49.7 years to 32.4 in the same period, Lesotho from 49.5 to 35.1, and Botswana from 56.1 to 39.7.
"With the onset of HIV/AIDS we have seen a lot of the work we have done, and the gains we have achieved, being eroded," says Wilfred Mlay, who directs African operations for World Vision, a privately funded Christian relief and development organization at work in 25 sub-Saharan countries. Consequently, Dr. Mlay says by phone from Nairobi, Kenya, World Vision now is working hard to help African governments provide AIDS education and assist the most vulnerable, teaching both sexual abstinence outside marriage and the use of condoms. Some 99 percent of HIV infections in Africa in 2001 were caused by unsafe sex practices, according to a study by the World Health Organization (WHO) released in 2002. That leaves hope that lifestyle changes can lower infection rates.
World Vision also supports people with AIDS by giving them nutrition and medications. Keeping parents healthy and alive longer means fewer orphans who must be cared for. "We are beginning to see some minor changes" in behaviors, Mlay says.
"If you were to take AIDS away, I think you would see gains [in longevity] everywhere," says John Bongaarts, vice president for policy research at the Population Council in New York. "Overall, the developing world is a success story."
Based on current UN projections, HIV/AIDS is expected to be the source of so many fatalities that by 2025 these countries will have 14 percent fewer people than they would have otherwise. Projections of HIV/AIDS fatalities in China and India suggest a difficult battle ahead for those two countries as well.
The burden on families will be "staggering," the report says. But it adds: "The course of the HIV/AIDS epidemic is by no means predetermined. The eventual course of the disease depends on how individuals, communities, nations, and the world respond to the HIV/AIDS threat today and tomorrow."
Still, the cost of caring for those already sick and their families can be overwhelming. In the United States, it costs about $10,000 per year to treat a person who is diagnosed with HIV, Dr. Bongaarts says. "In many of these sub-Saharan countries, the governments spend less than $10 per year per capita on health. So there's not much you can do with that money to treat people." Generic versions of AIDS drugs can substantially cut the cost. "But even so, that is an enormous expense," he says.
Every year of life expectancy gained is estimated to raise per capita gross domestic product in a country by about 4 percent. That's prompted some researchers to question whether development aid to Africa, only about 10 percent of which is aimed at improving health, is being properly spent. It's in everyone's interest "to overcome what I call the 'longevity di- vide,' " Dr. Butler says.
While the per capita GDPs of sub- Saharan countries have not dipped as dramatically as their longevity rates, that measure can be deceiving, Hill says. The deaths of young adults have reduced the labor force, but that has allowed survivors to pick up extra work and boost their own earnings. Thus, the fall in per capita GDP doesn't look so bad.
Longevity is one of several measures the UN uses to determine a population's well-being, rather than simply tracking wealth per capita. Its Human Development Index also includes school enrollment, literacy, and income to produce a broader picture. "People are the real wealth of nations," concludes a report last July by the UN Development Program.
To attack Africa's health problems, not only money but new ideas are needed, Butler says, such as a vaccine to protect against malaria, which is linked to more than 1 million deaths a year worldwide. Some $2.5 billion a year - 10 times what is being spent now - is needed to combat malaria in Africa, the WHO said this week. Also needed is a way to get vaccines to remote villages without spoiling.
Though vaccines are seen as important, traditionally researchers cite rising incomes, better education, healthier lifestyles, and cleaner environments as the major keys to increasing longevity.
Residents of developed nations usually live longest, experts believe, because they have access to basic amenities such as clean drinking water and modern sanitation. Places with the longest life expectancy at birth are:
Country Life expectancy*
1. Japan 81.5 years
2. Sweden 80.0
3. Hong Kong 79.9
4. Iceland 79.7
5. Canada 79.3
6. Spain 79.2
7. Australia 79.1
(tie) Israel 79.1
(tie) Switzerland 79.1
10. France 78.9
*for a child born in 2002
Source: UN Development Program