Children born today in the United States can expect to live nearly 78 years. That life expectancy is a great leap forward from 1900, when the average newborn couldn’t expect to reach age 50. Similar increases have been seen in in developed nations all around the world. In the 20th century, life expectancy increased more than it had in any century since the beginning of human civilization.
And the longer you live, the longer you can expect to live. Average life expectancy for a newborn American is 78 years, while it is 84 years for a 65-year-old and 87 years for a 75-year old.
But extending the lifespan has also increased the burden of diseases such as heart disease, stroke, cancer, arthritis, osteoporosis, macular degeneration, and other conditions that tend to affect older individuals. Most of these diseases, though, aren't inevitable consequences of aging. Instead, many are preventable.
Solid research from long-term studies such as the Framingham Heart Study, the Nurses' Health Study, and others have shown that the combination of not smoking, eating a healthy diet, exercising regularly, and keeping blood pressure, cholesterol, and blood sugar in check can prevent three-quarters or more of these chronic conditions.