It's getting harder to live longer in the U.S.

For all societies, life expectancy is a very basic quality-of-life measure. After all, if you aren’t alive, you don’t have any quality of life. And during the 20th century, industrialized nations added 30 years to life expectancy at birth across a broad spectrum of their populations. It’s one of humankind’s greatest achievements.  

Unfortunately, evidence is accumulating that in the 21st century, additional gains in life expectancy might accrue more narrowly and affect just the more wealthy and educated citizens. Let’s see why.

Much of the 20th century’s life expectancy gains resulted from more efficient sanitation and waste-disposal practices, cleaner water, the development and implementation of vaccinations, a more reliable supply of food, and the development of electricity and refrigeration to keep food fresh. 

These advances were broadly available to most citizens of industrialized nations, and they enabled many children and young adults to avoid acute illnesses that, in prior generations, would have prevented them from surviving to older ages.

Since many more people are surviving to later ages, future gains in life expectancies will come from preventing, mitigating and treating the chronic diseases associated with old age, such as heart disease, cancer, diabetes, strokes and dementia. Unfortunately, many elements of 21st century society actually hinder living long, healthy, financially secure lives.

For example, we’re bombarded with persuasive advertisements to eat -- and overeat -- unhealthy food and drink. These eating habits have been shown to contribute to obesity, diabetes and heart disease. Many of our poor eating habits can be attributed to the unhealthy food that’s marketed and sold to the majority of Americans.

Additionally, many of us don’t get enough exercise, and that fact, combined with the modern diet, results in many Americans becoming obese. That means many will most likely live shorter, sicklier lives.  

We’re also encouraged to be spenders, not savers, urged by companies to fork over all of our money -- even go into debt -- to buy the latest fashions or the newest gadget or car. This attitude of consumption is one reason retirement savings are so low, leading many people to not have enough money for even essential expenses during their retirement years. Several studies establish a correlation between low levels of wealth and income to shorter life expectancies.

So, it should be no surprise that future gains in life expectancies might not accrue broadly across the population but instead only to the subset of the population who are fortunate enough to have health insurance and have the knowledge and discipline to eat healthy foods and get enough exercise. Financial security will also accrue to those who earn a living wage and have the knowledge and discipline to make wise spending and savings decisions.

A number of studies have documented the growing divergence of life expectancies between socioeconomic groups, a phenomenon that started in the last half of the 20th century and continues to this day. 

The latest evidence comes from a recent study published by Lancet that compares life expectancies in 35 developed nations around the world. It shows that life expectancy at birth in the U.S is already lower than most other high-income countries and is projected to fall even further behind. For example, in 2030, life expectancy at birth for men in the U.S. is projected to be 79.5 years, similar to the Czech Republic. Life expectancy at birth for women is projected to be 83.3 years, similar to Croatia and Mexico.

Why is this? Contributing factors include the fact that the U.S. has the highest child and maternal mortality, homicide rate and body-mass index of any high-income country. The U.S. is also the only country in the Organization for Economic Cooperation and Development (OECD) without universal health coverage, and it has the largest share of unmet health care needs due to financial costs.

This is just the latest in a string of recent studies that document differences in life expectancies by educational attainment or income level. Another, from the National Academy of Sciences, shows that for the bottom quintile of earners, the remaining life expectancy in the U.S. at age 50 dropped by half a year for men born in 1960 compared to men born in 1930. For the top-quintile earners, remaining life expectancy increased by 7.1 years when comparing men born in 1930 vs. 1960.

The changes in life expectancies when comparing 1930 and 1960 births were more extreme for women in the bottom quintile of earners. For that group, remaining life expectancy at age 50 dropped by four years for women born in 1960 compared to women born in 1930. For the top-quintile earners, remaining life expectancy increased by 5.5 years when comparing women born in 1930 vs. 1960.

Smoking and obesity account for a large share of these disparities because such habits are more prevalent in lower-income, lower-educational-attainment groups than in higher-income, higher-educational-attainment groups.

While 20th century gains in life expectancy can be attributed to broad-based public health measures, 21st century gains will need to address tougher behavioral aspects of modern life -- what we eat, how much we exercise, how much we earn and how we spend our money. These reports show much work needs to be done to help all Americans live long, healthy, financially secure lives.

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    Steve Vernon helped large employers design and manage their retirement programs for more than 35 years as a consulting actuary. Now he's a research scholar for the Stanford Center on Longevity, where he helps collect, direct and disseminate research that will improve the financial security of seniors. He's also president of Rest-of-Life Communications, delivers retirement planning workshops and authored Money for Life: Turn Your IRA and 401(k) Into a Lifetime Retirement Paycheck and Recession-Proof Your Retirement Years.