The death rates of some of the world’s deadliest disease killers are declining and doctors and researchers are at a loss to fully explain it. As much as we want to pat our doctors and medical researchers on their collective backs for their work it doesn’t completely explain what’s going on, according to an article in the New York Times.
Major diseases including colon cancer, dementia and heart disease are declining in wealthy countries and improved diagnosis and treatment doesn’t fully explain it. It appears we are starting to make progress against some of the major diseases associated with aging. They still kill millions of people but they are occurring later in life so people are generally living longer.
Colon cancer is one example. Overall cancer death rates have been falling since the 1990’s but the colon cancer death rate cut (50%) is especially sharp and the reasons why aren’t clear. As best as researchers can figure out improved and increased screenings count for about half of the decline of the death rate.
This has happened with other diseases in the past. In the 1930’s stomach cancer was the leading cancer killer of Americans, now it’s down to 1.8% of cancer deaths. We are eating less foods preserved by salting and smoking and we use antibiotics that kill a bacteria that can cause it, but it looks like something else is going on.
Other diseases (for developed nations, anyways) that aren’t nearly the threat they used to be include tuberculosis (in the early 20th century one out of every 170 Americans lived in a tuberculosis sanitarium, or the equivalent of about two million Americans today) and heart disease (which became the top killer after tuberculosis faded but cancer is expected to soon kill more Americans than heart disease).
It’s not just particular diseases are become less threatening, it’s all chronic disease as a whole. If you group together all chronic diseases the overall death rate is falling. All of those diseases are linked to aging. There may be fundamental changes going on with the cellular process of aging resulting in a slow, overall improvement in the length of our lives.