Today's adults are less healthy than previous generations
23 April 2013
The adults of today are less "metabolically" healthy than their
counterparts of previous generations, even though they have greater life
expectancy, according to a large population study from the Netherlands.
The study compared generational shifts in a range of well
established metabolic risk factors for cardiovascular disease. The
investigators concluded that "the more recently born generations are
doing worse", and warn "that the prevalence of metabolic risk
factors and the lifelong exposure to them have increased and
probably will continue to increase".
The study, reported in the European Journal of Preventive
Cardiology, analysed data on more than 6,000 individuals in the
Doetinchem Cohort Study, which began in 1987–1991 with follow-up
examinations after six, 11, and 16 years. The principal risk factors
measured were body weight, blood pressure, total cholesterol levels
(for hypercholesterolaemia) and levels of high-density lipoprotein
(HDL) cholesterol, which is considered "protective".
The subjects were stratified by sex and generation at baseline
into ten-year age groups (20–29, 30–39, 40–49, and 50–59 years); the
follow-up analyses aimed to determine whether one generation had a
different risk profile from a generation born ten years earlier —
what the investigators called a "generation shift".
Results showed that the prevalence of overweight, obesity, and
hypertension increased with age in all generations, but in general
the more recently born generations had a higher prevalence of these
risk factors than generations born ten years earlier.
For example, 40% of the males who were in their 30s at baseline
were classified as overweight; 11 years later the prevalence of
overweight among the second generation of men in their 30s had
increased to 52% (a statistically significant generational shift).
In women these unfavourable changes in weight were only evident
between the most recently born generations, in which the prevalence
of obesity doubled in just 10 years.
Other findings from the study included:
- Unfavourable (and statistically significant) generation
shifts in hypertension in both sexes between every consecutive
generation (except for the two most recently born generations of
- Unfavourable generation shifts in diabetes between three of
the four generations of men, but not of women.
- No generation shifts for hypercholesterolaemia, although
favourable shifts in HDL cholesterol were only observed between
the oldest two generations.
As for the overall picture, and based on the evidence of a
"clear" shift in the prevalence of overweight and hypertension, the
investigators emphasise that "the more recently born adult
generations are doing worse than their predecessors".
Evidence to explain the changes is not clear, they add, but note
studies reporting an increase in physical inactivity. What do the
findings mean for public health?
First author Gerben Hulsegge from the Dutch National Institute
for Public Health and the Environment emphasises the impact of
obesity at a younger age. "For example," he explains, "the
prevalence of obesity in our youngest generation of men and women at
the mean age of 40 is similar to that of our oldest generation at
the mean age of 55.
"This means that this younger generation is ’15 years ahead’ of
the older generation and will be exposed to their obesity for a
longer time. So our study firstly highlights the need for a healthy
body weight —by encouraging increased physical activity and balanced
diet, particularly among the younger generations.
"The findings also mean that, because the prevalence of smoking
in high-income countries is decreasing, we are likely to see a shift
in non-communicable disease from smoking-related diseases such as
lung cancer to obesity-related diseases such as diabetes.
"This decrease in smoking prevalence and improved quality of
health care are now important driving forces behind the greater life
expectancy of younger generations, and it's likely that in the near
future life expectancy will continue to rise — but it's also
possible that in the more distant future, as a result of our current
trends in obesity, the rate of increase in life expectancy may well
slow down, although it's difficult to speculate about that."
Hulsegge G, Susan H, Picavet J, et al. Today’s adult generations
are less healthy than their predecessors: Generation shifts in
metabolic risk factors: the Doetinchem Cohort Study. Eur J Prevent
Cardiol 2013; DOI: 10.1177/2047487313485512.