Kaare Christensen, from the University of Southern Denmark, and colleagues have completed a review of aging and its impact on healthcare systems, finding that “If the pace of increase in life expectancy in developed countries over the past two centuries continues through the 21st century, most babies born since 2000 in France, Germany, Italy, the UK, the USA, Canada, Japan, and other countries with long life expectancies will celebrate their 100th birthdays.”  The team’s specific findings include that:
• Since the 1950s, and particularly since the 1970s, mortality in people 80 and older has declined. In 1950 about one in 10 80-year-old women died before 81. About 50 years later, the rate was 1 in 20.
• Improvements in health in developed countries will likely continue for the foreseeable future.
• Disease trends are mixed. Some evidence suggests rates of disease and chronic conditions have increased in older individuals. On the other hand, survival among patients with potentially fatal illness has improved (notably cancer and heart disease). Obesity poses a major threat, but effective therapies exist to modify the consequences of obesity (such as hypertension and hyperlipidemia).
• Most studies have shown improvement or no change in mobility and function.
• Life expectancy in perceived good health has increased, life years without disability have increased, and life years with severe disability have declined.
While the growing population of very old individuals will challenge nations' healthcare resources, the team submits that recent trends suggest the strain on society will be manageable, noting that: "The 21st century could be a century of redistribution of work … spread[ing] work more evenly across populations and over the ages of life. Individuals could combine work, education, leisure, and child-rearing in varying amounts at different ages."