A new study was
recently published that is so compelling that it deserves its very own feature
article. The study is titled “Impact of healthy lifestyle factors on life
expectancies in the US population” and it was published in the journal Circulation. The authors of this
investigation are the very best of the Harvard School of Public Health’s Department
of Nutrition faculty, which includes Dr. Walter Willett, Dr. Frank Hu and Dr.
Meir Stampfer (Reference 1).
Most nutrition research
focuses on a very specific aspect of lifestyle and its impact on health. For
example, “eating red meat increases incidence of colon cancer” or “eating
oatmeal decreases serum cholesterol”. What makes this study so interesting is
that several lifestyle behaviors are combined so we can see their cumulative
impact on health.
The Article
This investigation
used subjects from both The Nurses’ Health Study and The Health Professional
Follow-up Study for a total of 123,219 men and women. The researchers created 5
lifestyle factors and scored each subject on how well they followed the
behavior. Here is the scoring system:
1) Smoking: If the
subject never smoked they received a score of 1. If they were a current smoker
or had smoked in the past, they received a score of 0.
2) Physical Activity:
If the subject engaged in 30 minutes or more of moderate to vigorous physical
activity each day they received a score of 1. If they did less than this, they
received a score of 0.
3) Alcohol
Consumption: Low risk was considered an alcohol consumption of 5 to 15 grams
per day for women (which equals 2.5-7.5 drinks per week) and 5 to 30 grams per
day for men (which equals 2.5-14 drinks per week). If the subject’s alcohol
consumption was in this range, they received a score of 1, if not they received
a score of 0.
4) Body Mass
Index: Low risk was considered a BMI between 18.5-24.9. If the subject’s BMI
was in this range, they received a score of 1, if not they received a score of
0.
5) Diet: Subjects
received a score of 1 for this variable if their diet was in the top 40% of the
cohort distribution for the Alternate Healthy Eating Index. This diet score is
based on a high consumption of vegetables, fruits, nuts, whole grains,
polyunsaturated fats and long chain omega 3 fatty acids and a low intake of red
and processed meats, sugar sweetened beverages, trans fat and sodium.
Each subject was
given a score for the 5 lifestyle factors. A perfect lifestyle would be a score
of “5”, while adhering to none of the lifestyle factors would yield a score of “0”. Subjects were followed for up to 34 years.
Results
When comparing
subjects who followed all 5 factors to subjects following none:
-Risk of all-cause
mortality was 74% lower in subjects that followed all 5 factors.
-Risk of death
from cancer was 65% lower in subjects that followed all 5 factors.
-Risk of death
from cardiovascular disease was 82% lower in subjects that followed all 5
factors.
Starting at age
50, women following all 5 factors could expect to live another 43.1 years,
while women following none of the factors could expect to live another 29
years.
Starting at age
50, men following all 5 factors could expect to live another 37.6 years, while
men following none of the factors could expect to live another 25.5 years
The researchers
ran an additional analysis with a stricter criterion for the lifestyle score.
Body mass index: A
score of 1 was given to those with a BMI between 18.5 and 22.9.
Physical Activity:
A score of 1 was given to those exercising more than 52 minutes per day.
Diet: A score of 5
was given to those in the top 20% of the distribution for the Alternate Healthy
Eating Index.
The scoring for
smoking and alcohol consumption were kept the same.
Women who followed
this expanded score lived 20.5 years longer than those that followed none of
the lifestyle factors. For men, the number was 19.6 years.
Conclusions And Recommendations
These results are
truly remarkable. To think that by living a healthy lifestyle you could add up
to 20 years to your life is amazing. The coolest part is that this study does
not take into account quality of life, which is much higher if you follow these
habits. If you are able to hit all 5 of these behaviors consistently, you will
notice significant and positive changes in your energy, mood, immune system,
confidence, mental focus/performance and how you handle stress.
The take home
message on this is one is simple. Go through each of the 5 lifestyle factors
and give yourself a score. If you are at 5, you are all set and keep up the
good work. If you are hitting less than 5, do your best to work towards a
perfect score. Will it be easy to attain all 5 of these? Probably not. However,
the effort you put into a healthy lifestyle is paid back to you many times over.
It all begins with making your health a priority.
References
1) Li Y, et al.
Impact of healthy lifestyle factors on life expectancies in the U.S. population
Circulation 2018 DOI: 10.1161/CIRCULATIONAHA.117.032047.