In the United States, life expectancy at birth is 79. Some people won’t live that long while others will survive much longer. What are the odds you’ll make it to 80? To 100?
From heredity to gender and education to income, scientists have identified a number of basic characteristics that are linked somehow to life expectancy and that may have an impact on how long you live.
To begin with, there’s some truth to the old adage, to live a long life, choose your parents wisely. Research by the New England Centenarian Study (NECS) suggests that extreme longevity seems to run in families. If you have centenarians in your family tree, you have a better chance than most of surviving to a great age and of staying healthy until very late in life.
Nevertheless, according to NECS founder Thomas T. Perls, MD, heredity isn’t everything, even for centenarians. The secret to living a long life is having the right mix of good genes and healthy habits. Scientists estimate that if you’re like most people, heredity determines only about 30 percent of how well you age (and, presumably, how long you live). Your lifestyle and environment have a much bigger impact.
Women Have an Advantage
If you’re a woman almost anywhere on the planet, you’re likely to outlive the men your age. In the United States, the average woman’s life expectancy at birth is about 81, five years longer than the average man’s.
Women in developed countries have been out-surviving men for centuries, despite the risks of childbirth. During the Middle Ages, men complained that this was unnatural because males were stronger and should live longer. Scientists still puzzle over why they don’t; there are many theories, but no one really knows.
Yet according to the Eight Americas study, published in 2008, the gender gap in longevity has shrunk to just five years from almost eight in 1979. In fact, in some parts of the United States, women’s life expectancy is actually dropping. That’s probably because more women smoke today than in the past, and fewer men do.
Life Expectancy Lengthens with Age
The longevity statistic most often quoted is life expectancy at birth. It states how long the average baby, born to a particular group in a specific year, is likely to live. For example, researchers predict that female infants born in 2006 to Asian-American families living in New Jersey will survive to about 91. A population’s life expectancy reflects its general health, so scientists watch those numbers closely.
Most Americans live longer than the national life expectancy of 78, says economist and columnist Ed Lotterman. That’s because when longevity is calculated from birth, stillbirths and deaths during the first few years of life pull down the average.
Life expectancy can be based on any age, and it turns out that the older you are, the longer you’re expected to live—up to a point. If you’re American, once you’re 55, experts predict you’ll survive to about 82.
• At 65, expect to live to about 84
• At 75, to nearly 87
• At 85, to roughly 92
• At 95, to about 98
By the time you reach 100 or more, demographers concede you only another two years, but centenarians often prove them wrong.
One last thing: calculations of life expectancy assume that conditions won’t change much in the future. That means a breakthrough in treating cancer could propel estimates upward while a global pandemic could depress them.
Life expectancy, in other words, is a useful educated guess.
White Americans Don’t Live the Longest
Beyond gender, your racial or ethnic background is linked to your longevity. According to the Centers for Disease Control and Prevention, in the United States, Asian Americans have the longest life expectancy at almost 87 years. These are the life expectancies for other groups:
• Hispanics, 83
• Non-Hispanic whites, 79
• Native Americans, 74
• African Americans, 73
The news that Hispanics generally live longer than non-Hispanics surprised some researchers because Spanish-speaking Americans tend to have less income and education than other ethnic groups. Thirty-six percent of today’s Hispanics were born outside the United States, and experts suggest they have a health advantage because only the hardiest souls immigrate—in fact, US immigrants of every race tend to live about three years longer than people born in America.
Education and Income Make a Difference
If you’ve been to college, whether you graduated or not, you can expect to live longer than someone with just a high school education. Harvard health economist Ellen R. Meara confirmed that in a 2008 study. According to her calculations, 25-year-olds who attended college will likely survive to 82 while those with less schooling have a life expectancy of 75. Meara’s study found that those with less education are more likely to smoke and therefore die earlier. In addition, because those with only a high school diploma tend to earn less, they are more apt to live in substandard housing or a high-crime area and to be without health insurance.
The wealthier you are, the longer you’re likely to live, according to many studies. In 2010, investigators from Wilder Research compared life expectancies, zip code by zip code, in Minnesota’s Twin Cities. They found that the higher an area’s median household income, the longer its residents are likely to survive. Where the annual median income is $35,000 or less, people have a life expectancy at birth of less than 75. Where it is $75,000 or more, residents can expect to survive to about 83.
Even if your income is moderate, just living in those well-to-do zip codes may extend your life, according to sociologist Craig Helmstetter, who co-authored the Twin Cities report on life expectancy. That‘s partly because wealthier neighborhoods offer supermarkets with affordable fresh food and have other residents who consider a physically active lifestyle the norm.
It’s not hard to guess why income is important. If you don’t have much money, your diet is apt to be unhealthy—fast food is cheap food—and you may live a more sedentary life if there’s no safe place in your neighborhood to exercise outdoors. People with low incomes also are more likely to smoke than those who are better off.
In addition, if you’re struggling financially or are unemployed, you may not have health insurance. Without it, if you develop cancer, for example, you’re more likely to be diagnosed at a late stage when the disease may not be curable. Without good medical care, you’ll have more trouble managing a chronic problem such as diabetes.
Still, scientists say access to medical care explains only a small part of the differences in life expectancy in the United States. There’s more and more evidence that your own health habits make a huge difference to how long you’re likely to live. Experts at Harvard say that if Americans refrained from smoking and kept their weight, blood pressure and blood sugar levels down, men would survive about four years longer than they do now and women would extend their lives by five years.
That’s encouraging because unlike heredity, gender, race and even income, your health habits are something you can control.
Flora Davis has written scores of magazine articles and is the author of five nonfiction books, including the award-winning Moving the Mountain: The Women’s Movement in America Since 1960 (1991, 1999). She currently lives in a retirement community and continues to work as a writer.
