How is it possible that the US spends the most money on health care and yet has one of the lowest life expectancy rates of any industrialised country?
Perhaps those of us who work in health care have been looking at it all wrong for too long.
Healthy lifestyles and longevity
Researchers at Harvard’s T.H. Chan School of Public Health conducted an in-depth study on the impact of health habits on life expectancy, using data from the well-known Nurses’ Health Study (NHS) and Health Professionals Follow-up Study (HPFS). This means they had data on a large number of people over a very long period of time. The NHS studied over 78,000 women and followed them from 1980 to 2014, and the HPFS included over 40,000 men and followed them from 1986 to 2014, which is over 120,000 participants, 34 years of data for women and 28 years of data for men.
The researchers looked at NHS and HPFS data on diet, physical activity, weight, smoking and alcohol consumption, collected through regularly administered validated questionnaires.
What exactly is a healthy lifestyle?
These five areas were chosen because previous research has shown that they have a significant impact on the risk of premature death. The following explains how these healthy habits were defined and measured:
- a healthy diet, which was calculated and assessed on the basis of reported intakes of healthy foods such as vegetables, fruits, nuts, whole grains, healthy fats and omega-3 fatty acids, and unhealthy foods such as red and processed meats, sugar-sweetened beverages, trans fats and sodium.
- healthy physical activity, which means at least 30 minutes of moderate to vigorous physical activity per day.
- a healthy body weight, defined as a normal body mass index (BMI) between 18.5 and 24.9.
- smoking, yes, there is no healthy level of smoking. ‘Healthy’ in this context means that you have never smoked.
- moderate alcohol consumption, reported as 5 to 15 grams per day for women and 5 to 30 grams per day for men. Generally, one drink contains about 14 grams of pure alcohol. This is the equivalent of 12 ounces of regular beer, 5 ounces of wine or 1.5 ounces of spirits.
Researchers also looked at data on age, ethnicity and drug use, as well as comparative data from the National Health and Nutrition Examination Surveys and the Centres for Disease Control and Prevention’s comprehensive web-based epidemiological survey data.
Does a healthy lifestyle make a difference?
It turns out that healthy habits make a big difference. According to this analysis, people who met the criteria for all five habits lived significantly longer than those who didn’t: 14 years for women and 12 years for men (if they had these habits by the age of 50). People who did not have any of these habits had a significantly higher risk of dying prematurely from cancer or cardiovascular disease.
The study researchers also calculated life expectancy according to how many of these five healthy habits people had. Only one healthy habit (and it didn’t matter which one) … only one … extended life expectancy for both men and women by two years. Not surprisingly, the more healthy habits people had, the longer they lived. This is one of those situations where I wish I could print out graphs for you because they are so cool.
This is a big deal. And it corroborates previous similar studies – lots of previous similar studies. A 2017 study using data from the Health and Retirement Study found that people over age 50 who were of normal weight, had never smoked, and consumed alcohol moderately lived on average seven years longer. A mega-analysis of 15 international studies in 2012 involving more than 500,000 people found that more than half of premature deaths are caused by unhealthy lifestyles such as poor diet, physical inactivity, obesity, excessive alcohol consumption and smoking. And the list of supporting studies goes on.