You know that getting exercise, eating vegetables and quitting smoking are good for you. A new study shows just how good they are, in terms of the number of years they can add to your life.
American women who followed five "healthy lifestyle factors" lived about 14 years longer than women who followed none of them, according to a report published Monday in the journal Circulation. For men, the difference was about 12 years.
The five healthy lifestyle factors identified in the study should come as no surprise to anyone: eating a nutritious diet, exercising at least 30 minutes a day, maintaining a healthy weight, not smoking, and drinking in moderation.
The only surprise might be just how much these healthy choices can pay off.
The biggest benefits were seen by those who adhered to all five factors. But following any one of them was associated with extra years of life –- and the more of them people followed, the longer they lived.
Researchers quantified these benefits by analyzing data on 78,865 women who enrolled in the Nurses' Health Study in 1976 and 44,354 men who joined the Health Professionals Follow-Up Study in 1980. By 2014, 42,167 of these men and women had died, including 10,689 who died of cardiovascular disease and 13,953 who succumbed to cancer.
The risk of death was not evenly distributed among study participants. After accounting for factors such as age, ethnicity, vitamin use and family history of certain diseases, the researchers saw a strong correlation between the lifestyle choices people made and their chances of being alive in 2014.
Men and women who were 5-for-5 on the lifestyle factors were 74% less likely to die during the study period than their counterparts who were 0-for-5. In particular, they were 65% less likely to die of cancer and 82% less likely to die of cardiovascular disease, the researchers found.
At age 50, the women who had the healthiest lifestyles could expect to live until age 93, 14 years longer than women who had the least healthy lifestyles. Among 50-year-old men, the healthiest could expect to live until age 87, 12 years longer than their least-healthy counterparts.
However, only 8% of American adults were meeting all five criteria for a healthy life as of 2006, the study authors noted. Being overweight or obese was the primary obstacle, they added.
Altogether, about half of the premature cancer deaths and nearly three-quarters of the premature deaths due to cardiovascular disease could be blamed on a failure to maintain a healthy lifestyle, the researchers found. But it doesn't have to be this way.
"Prevention should be a top priority for national health policy, and preventive care should be an indispensable part of the healthcare system," the researchers wrote.
Here's a closer look at each of the five factors:
People with a body mass index in the "normal" range — between 18.5 and 24.9 — were considered to have a healthy weight.
Women who didn't follow any of the healthy lifestyle factors had an average BMI of 29.8, just shy of the border between overweight and obesity. Men who scored 0 out of 5 on the lifestyle factors had an average BMI of 28.2. In general, the healthier a person's overall lifestyle, the lower his or her BMI.
Compared to a reference group of people with a BMI at the high end of the normal range (between 23 and 24.9), those with a BMI in the overweight range (between 25 and 29.9) were 5% more likely to die for any reason during the course of the study. Obese people with a BMI in the 30-to-34.9 range were 25% more likely to meet this fate, and the risk was 67% higher for those with a BMI above 35.
Being obese was associated with a 12% to 24% increased risk of dying of cancer during the study period, the researchers found. But the bigger health hazard was cardiovascular disease. Compared to the reference group, those who were overweight were 16% more likely to die of this disease during the study period. For those with a BMI between 30 and 34.9, the risk was 66% higher, and for those with a BMI over 35 the risk was more than double.
Getting at least 30 minutes of moderate or vigorous exercise each day qualified as having a healthy amount of physical activity.
People who met this goal were 56% less likely to die of any cause during the study period compared to people who got no exercise at all. In addition, their chances of dying of cancer were 45% lower and their chances of dying of cardiovascular disease were 61% lower.
Any amount of exercise appeared to reduce all of these risks. For instance, those who got between 3.5 and 5.9 hours of moderate to vigorous exercise per week were 50% less likely than total couch potatoes to die for any reason. People who exercised 1 to 3.4 hours per week saw their risk fall by 44%. Even those who exercised for less than 1 hour per week were 35% less likely to die of any cause while they were being tracked.
The healthiest people on this score were the ones who had never smoked. Compared to this group, people who smoked at least 25 cigarettes per day were nearly three times more likely to die of cancer, cardiovascular disease or any other cause during the course of the study.
Current smokers who smoked fewer cigarettes per day were still at least twice as likely as never-smokers to die during the study period.
Among former smokers who had quit, the risk of death due to cancer was 50% higher during the study period, and the risk of death due to cardiovascular disease and for any cause was about 40% greater than for never-smokers.
A healthful diet was one that scored in the top 40% based on the Alternate Healthy Eating Index. Under this criteria, high scores go to people who eat at least five servings of vegetables and four servings of fruit per day, along with at least one serving of nuts or legumes, no red meat or sugary drinks, and a minimum of sodium, among other things.
Compared to men and women whose AHEI scores landed them in the bottom 20%, those in the top 20% were 37% less likely to die for any reason during the study period. Those in the second-highest group were 30% less likely to meet this fate.
Compared to the baseline group with the lowest AHEI scores, those in the top group were 30% less likely to die of cancer and 33% less likely to die of cardiovascular disease during the course of the study. People in the second-highest group saw these risks fall by 24% and 25%, respectively.
To be considered a moderate drinker — the healthful choice — women had to consume between 5 and 15 grams of alcohol per day. For men, the ideal range was between 5 and 30 grams per day.
Men and women who drank more than 30 grams of alcohol daily were 25% more likely than their moderate peers to die of any reason while they were being tracked. In addition, their risk of dying of cancer was 21% higher and their risk of dying of cardiovascular disease was 17% higher.
Interestingly, men and women who abstained from alcohol altogether were 27% more likely than the moderate drinkers to die of any cause during the study period. That was similar to the risk for the heaviest drinkers.
Among the teetotalers, the increase in all-cause mortality seemed be fueled by their increased risk of death due to cardiovascular disease, which was 49% higher than for moderate drinkers during the study period.
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This story has been updated with additional information about the risks and benefits associated with each of the five lifestyle factors.