Abstract 
 
 Background—Americans have a shorter life expectancy compared with residents of almost all other high-income countries. We aim to estimate the impact of lifestyle factors on premature mortality and life expectancy in the US population. 
 
 Methods—Using data from the Nurses' Health Study (1980-2014; n=78 865) and the Health Professionals Follow-up Study (1986-2014, n=44 354), we defined 5 low-risk lifestyle factors as never smoking, body mass index of 18.5 to 24.9 kg/m2, ≥30 min/d of moderate to vigorous physical activity, moderate alcohol intake, and a high diet quality score (upper 40%), and estimated hazard ratios for the association of total lifestyle score (0-5 scale) with mortality. We used data from the NHANES (National Health and Nutrition Examination Surveys; 2013-2014) to estimate the distribution of the lifestyle score and the US Centers for Disease Control and Prevention WONDER database to derive the agespecific death rates of Americans. We applied the life table method to estimate life expectancy by levels of the lifestyle score. 
 
 Results—During up to 34 years of follow-up, we documented 42 167 deaths. The multivariable-adjusted hazard ratios for mortality in adults with 5 compared with zero low-risk factors were 0.26 (95% confidence interval [CI], 0.22-0.31) for all-cause mortality, 0.35 (95% CI, 0.27-0.45) for cancer mortality, and 0.18 (95% CI, 0.12-0.26) for cardiovascular disease mortality. The population-attributable risk of nonadherence to 5 low-risk factors was 60.7% (95% CI, 53.6-66.7) for all-cause mortality, 51.7% (95% CI, 37.1-62.9) for cancer mortality, and 71.7% (95% CI, 58.1-81.0) for cardiovascular disease mortality. We estimated that the life expectancy at age 50 years was 29.0 years (95% CI, 28.3-29.8) for women and 25.5 years (95% CI, 24.7-26.2) for men who adopted zero low-risk lifestyle factors. In contrast, for those who adopted all 5 low-risk factors, we projected a life expectancy at age 50 years of 43.1 years (95% CI, 41.3-44.9) for women and 37.6 years (95% CI, 35.8-39.4) for men. The projected life expectancy at age 50 years was on average 14.0 years (95% CI, 11.8-16.2) longer among female Americans with 5 lowrisk factors compared with those with zero low-risk factors; for men, the difference was 12.2 years (95% CI, 10.1-14.2). 
 
 Conclusions—Adopting a healthy lifestyle could substantially reduce premature mortality and prolong life expectancy in US adults. ||||| This crawl of online resources of the 115th US Congress was performed on behalf of The United States National Archives & Records ||||| (CNN) Want to prolong your life expectancy by more than a decade? A new study suggests that you can do just that by following these five healthy habits: never smoke, maintain a healthy body-mass index, keep up moderate to vigorous exercise, don't drink too much alcohol, and eat a healthy diet. 
 
 Adhering to those five lifestyle factors at age 50, compared with not adhering to any of them, was associated with 14 additional years of life expectancy among women and 12.2 additional years among men in the study, published in the journal Circulation on Monday. 
 
 Each of those factors is significantly associated with a reduced risk of dying from the top two killers in the United States, cardiovascular disease and cancer , according to the study. 
 
 About 610,000 people die of heart disease in the US each year, which is about one in every four deaths, according to the US Centers for Disease Control and Prevention 
 
 About 609,640 Americans are expected to die of cancer this year, according to the American Cancer Society 
 
 JUST WATCHED Life expectancy on the rise Replay More Videos ... MUST WATCH Life expectancy on the rise 01:22 
 
 "These are some of the leading causes of premature death, so by preventing or reducing the incidence of those diseases, it promotes longevity, and it also improves survival after diagnosis of those diseases," said Dr. Meir Stampfer, a professor of medicine at Harvard Medical School and professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health , who was a co-author of the study. 
 
 "We can do so much better for having a long healthy life by pretty simple minimal changes in our behavior, and only 8% of adults in our country are adhering to these," he said. "The main take-home message is that there's huge gains in health and longevity to be had just by simple changes in our behavior pattern, and as a country, I think we need to make it easier for ourselves to do this by promoting tobacco cessation, by providing better environments for physical activity and so on." 
 
 Photos: The countries where people live longest Photos: The countries where people live longest Italy – The Italian diet, combined with a climate that promotes outdoor activity, is thought to play an important role in healthy aging among Italians. Hide Caption 1 of 11 Photos: The countries where people live longest Japan – Japan has the longest-living population in the world, with the average 60-year-old going on to live until age 86. Experts say this is due to good diets, active lifestyles and supportive family structure. Hide Caption 2 of 11 Photos: The countries where people live longest Spain – Spain's version of the Mediterranean diet combined with strong family networks is believed to enhance life expectancy among its population. In Spain, average life expectancy at age 60 is 85. Hide Caption 3 of 11 Photos: The countries where people live longest France – France also tied second with the other countries in southern Europe with, those over 60 living to the age of 85, on average. Pictured, a couple sit on a bench in Cannes. Hide Caption 4 of 11 Photos: The countries where people live longest Andorra – Diet and outdoor lifestyle in Andorra help to keep the country's elderly population healthy. Hide Caption 5 of 11 Photos: The countries where people live longest Australia – The universal health care system in Australia, combined with Australians' outdoor lifestyle, help people live longer, according to experts. Pictured, a war veteran during ANZAC Day. Hide Caption 6 of 11 Photos: The countries where people live longest New Zealand – The outdoor lifestyle and health infrastructure are credited with keeping New Zealanders healthy and living longer. Hide Caption 7 of 11 Photos: The countries where people live longest Switzerland – Switzerland's wealth and health care system are credited with boosting the nation's longevity. Hide Caption 8 of 11 Photos: The countries where people live longest Singapore – After Japan, Singapore has Asia's highest life expectancy at age 60. Hide Caption 9 of 11 Photos: The countries where people live longest Monaco – The extensive wealth of the residents of Monaco is likely to be the main factor supporting health in the elderly. Hide Caption 10 of 11 Photos: The countries where people live longest San Marino – Like many of the other long-lived countries, San Marino's strong economy and infrastructure are thought to be the reason for its long-lived residents. Hide Caption 11 of 11 
 
 Globally, the US ranks 43rd when it comes to life expectancy at birth, with an average life expectancy of 80, according to 2017 data from the Central Intelligence Agency's World Factbook 
 
 The three countries ranked highest for life expectancy at birth are Monaco , with 89.4 years; Japan , with 85.3 years; and Singapore , with 85.2 years, according to those data. 
 
 The countries with the lowest life expectancy at birth, based on that data, are Chad , with 50.6 years; Guinea-Bissau , with 51 years; and Afghanistan , with 51.7 years. 
 
 The 'surprising' impact of behaviors on longevity 
 
 For the new study, researchers measured the association between those five lifestyle factors and premature death using data from the national Nurses' Health Study and the Health Professionals Follow-Up Study . The data came from 1980 to 2014 and included more than 122,000 people combined. 
 
 Then, the researchers used data from the National Health and Nutrition Examination Surveys to estimate the distribution of those modifiable lifestyle factors among adults in the United States. Those data, from 2013 to 2014, consisted of 2,128 adults, 50 to 80 years old. 
 
 The researchers also derived death rates of US adults using the CDC's Wide-Ranging Online Data for Epidemiologic Research database. 
 
 After analyzing the data, the researchers found that, in 2014, the overall projected life expectancy at age 50 was to live 33.3 more years for women and 29.8 more years for men. 
 
 Yet among the adults who reported that they adopted all five healthy lifestyle factors, the researchers found, they lived 43.1 more years among women and 37.6 more years among men. 
 
 Among those adults who reported that they adhered to none of the five healthy lifestyle factors, the researchers found that they lived only 29 additional years among women and 25.5 additional years among men. 
 
 "To me, the surprising outcome was how strong it was: what a big impact these simple behaviors could have on life expectancy," Stampfer said. "I was surprised that it was that pronounced." 
 
 Among the women, on average, about 30.8% of the life expectancy at age 50 that they gained from adopting five, versus zero, of those lifestyle factors was attributed to a reduced risk of cardiovascular disease death; 21.2% was attributed to a reduced risk of cancer and 48% to other causes of death. 
 
 Among the men, those percentages were 34.1% attributed to a reduced risk of cardiovascular disease death, 22.8% attributed to a reduced risk of cancer and 43.1% to other causes. 
 
 The study had some limitations, including that the data on adherence to the five lifestyle factors were all self-reported, making outcome vulnerable to measurement errors. 
 
 Also, the data analysis did not include measures of certain health conditions that are risk factors for a shorter life expectancy, such as diabetes or high blood pressure. 
 
 That limitation, however, "is both a strength and a limitation, in a way ... because what we're estimating here is the prolongation of life expectancy just based on behaviors," Stampfer said. 
 
 "Obviously, it's much better to do these healthy behaviors from childhood, really, but if you're beyond age 50, beyond age 60, beyond age 70, it's not too late," he added. 
 
 The factor that was seen as more 'powerful' 
 
 The findings should encourage and motivate people to adopt a healthier lifestyle, said Dr. Douglas Vaughan, chairman of the department of medicine in Northwestern University's Feinberg School of Medicine , who was not involved in the study. 
 
 Though the study highlighted how the combination of all five lifestyle factors could help prolong life expectancy, Vaughan pointed out how each individual factor also was tied to a reduced risk of premature death. 
 
 JUST WATCHED Why your BMI matters Replay More Videos ... MUST WATCH Why your BMI matters 01:17 
 
 "It looks like cigarette smoking has a more powerful effect than the other lifestyle changes or behaviors. Certainly, maintaining a reasonable body-mass index is a great way to protect oneself against the development of diabetes," Vaughan said. 
 
 Body-mass index, a calculation derived from a person's weight and height, is used as a screening tool for body fatness. A normal or healthy body-mass index is typically said to be between 18.5 and 24.9. 
 
 "So, in aggregate, we see the effect on longevity, but you can imagine it's largely through effects on cardiovascular risk and metabolic risk," Vaughan said. "It suggests potentially at a defined point in life, say age 50, if you adhere to a healthy paradigm like this, you can have an impact on your longevity and on your health span." 
 
 Follow CNN Health on Facebook and Twitter See the latest news and share your comments with CNN Health on Facebook and Twitter. 
 
 Dr. Jack Der-Sarkissian, a family medicine physician and assistant area medical director of Kaiser Permanente Los Angeles Medical Center , called smoking "the least-debated health risk factor." 
 
 "Beyond cancer risk, smoking contributes to lung disease, heart disease and diabetes. The study shows that even minimal smoking -- from one to 14 cigarettes a day -- is associated with increased death due to cancer and heart disease," said Der-Sarkissian, who was not involved in the new study. 
 
 As for some of the other lifestyle factors, "getting weight below a BMI of 30 appears to help considerably, according to the study. A higher body weight is linked to increased risk of diabetes and cancer, among other obesity-related conditions," he said. "The study suggests physical activity of at least 30 minutes a day of moderate or vigorous activities, including brisk walking."
– Harvard researchers say five things will help you live longer, and the list isn't all that surprising: exercise, eat a healthy diet, maintain a healthy body weight, don't drink too much, and don't smoke. More surprising is just how much of an effect those five combined factors have on longevity—an extra 14 years for women and 12 for men, according to the study in Circulation. Researchers looked at about 30 years of data on more than 78,000 women and 44,000 men and found that those who were five-for-five on the aforementioned list had a significantly better life expectancy at age 50 than those who didn't abide by any of the healthy habits. For women, it meant an additional 43 years for the healthiest group, compared to 29 years. For men, it meant an additional 37.6 years, compared to 25.5 years. “When we embarked on this study, I thought, of course, that people who adopted these habits would live longer," says co-author Meir Stampfer, per the Guardian. "But the surprising thing was how huge the effect was." The two big factors: Those with the healthiest lifestyles were less likely to get cancer or heart disease, notes CNN. The Harvard Gazette provides some specifics: Researchers defined regular exercise as 30 minutes or more per day of moderate to vigorous physical activity; moderate drinking is roughly one 5-ounce glass of wine per day for women and up to two for men; and the target body-mass index is between 18.5 and 24.9. Scientists say they undertook the study to better understand why the US has a shorter life expectancy (79.3 years) than most high-income countries. (Another study says it's all about eating smaller portions.)