Scientists are puzzled by fact that several major medical disorders like colon cancer, heart disease, dementia, etc, have been on the decline in the past 2-3 decades. This observation has been most marked in the wealthy well-developed western countries. While these disorders have not completely disappeared and can still cause significant morbidity and mortality, the numbers of people affected today are much less than in the past.
At least in the USA, it appears that the leading killers like heart disease, cancer and stroke are on the decline. In addition, people are living a lot longer and many have good health till the very end.
In just the past 3 decades, the rates of colon cancer have dropped by 50 percent and no one is able to explain this decline. Some experts claim that screening may be part of the answer but does not explain the entire story because screening is not mandatory and millions of people do not get themselves screened.
Similarly there has been a marked decrease in hip fractures over the past 3 decades. Although newer drugs to strengthen bone have been available for 2 decades, very few people have been taking these medications. So how did these people develop stronger or heavier bones? Experts say perhaps a better diet and exercise may be the explanation but overall the majority of elderly lead a sedentary lifestyle. Again there is no satisfactory answer.
Another disorder that has been declining is dementia. Latest reports indicate that since the 1980s, there has been a 20% decline in dementia every decade. Even though more people are living longer, the rates of dementia have not matched but gotten lower. Scientists believe that this may be due to better management of blood pressure, blood cholesterol, diabetes and heart disease, which also are risk factors for dementia.
Even heart disease, which has been the number one killer for Americans, has been dropping from its perch and has been replaced by cancer.
Finally stomach cancer, which was the number one cause of death in the US until the 1930s is now very rare, and only accounts for 1.8 percent of American cancer deaths. Why has this cancer disappeared? Some believe that perhaps an improved diet and refrigeration of foods may be the explanation.
The exact cause of the decline in these major medical disorders is not known but experts believe that our lifestyle may very well have to do with it. Today people are more aware of their body, and tend to eat healthy and exercise.