Disability is commonly defined as "difficulty or
dependency in carrying out activities essential to independent living".
With the number of disabled people expected to increase in coming years,
researchers feel there is a need to define preventive strategies and slow this
Previous research has shown that unhealthy behaviours (such
as physical inactivity, poor diet, smoking) have an adverse effect on health.
For instance, the risk of obesity, diabetes, cancer, poor cognitive function,
stroke, sudden cardiac death and mortality increases with the number of
Researchers from France and the UK therefore carried out a
study to investigate the relationship between unhealthy behaviours and the risk
of disability over a 12 year period.
They used data from the Three-City (3C) Dijon cohort study.
Between 1999 and 2001, the study included community-dwelling older people (more
than 65 years old) from the city of Dijon (France). Participants were
interviewed at that time about their lifestyle, including information on
smoking, diet, physical activity, and alcohol drinking. They were then followed
for the incidence of disability over 12 years.
Three levels of
Three levels of disability were assessed: mobility,
instrumental activities of daily living (IADL) and basic activities of daily
living (ADL). Mobility assessed the ability to do heavy work around the house,
walk half a mile, and climb stairs. IADLs included the ability to use a
telephone, manage medications and money, use public or private transport, and
do shopping, and, additionally for women, to prepare meals and do housework and
laundry. ADLs included bathing, dressing, toileting, transferring from bed to
chair and eating. Participants were considered disabled if they could not
perform at least one activity without any given level of help.
Low or intermediate physical activity, consumption of fruit
and vegetables less than once a day, smoking (current or having quit smoking
less than 15 years ago), and no (abstention or former) or heavy consumption of
alcohol were all considered as unhealthy behaviours. Characteristics were also
identified that may influence the relation between unhealthy behaviours and
disability such as cardiovascular disease, diabetes, depression, high BMI and
During the follow-up, 1 236 out of 3 982 (31%) participants
developed disability. The incidence of disability increased with age, from
3.4/1000 person-years in those aged 65-70 years to 288/1000 person-years in
those over 90 years of age. 922 participants died, of whom 702 were not
Participants who developed disability were older, more
likely to be women, and less educated than participants without disability, and
they had a worse health profile.
Participants reporting low or intermediate physical activity
had a 72% increased risk of disability, independently of the presence of other
unhealthy behaviours; similarly, the increased risk was 24% for people who
consumed fruits and vegetables less than once a day and 26% for current or
Participants with all three unhealthy behaviours were twice
as likely to develop disability. There was no association between alcohol
drinking and disability. About 30% of the association between unhealthy
behaviours and disability was explained by higher body mass index, lower
cognitive function, depressive symptoms, traumatisms, chronic conditions, and
Unhealthy behaviours also played a role in people who developed
disability more than four years after the beginning of the study. Thus, the
relation between unhealthy behaviours and disability is not due to persons who
became disabled shortly after the beginning of the study and changed their
lifestyle as a consequence.
In conclusion, "an unhealthy lifestyle, characterised
by physical inactivity, unhealthy diet, and smoking, is associated with a
greater hazard of disability" which increased with the number of unhealthy
behaviours. Researchers say, however, that these are "potentially
modifiable" and that these findings are in favour of "the potential
benefit of multi-behaviour interventions compared to single-behaviour