Some of the effects of daily habits on health begin to appear as early as age 40 and increase with age. Furthermore, preventive and health promotion interventions aimed at people reaching retirement age come too late. It is imperative to act earlier and adopt a comprehensive, lifelong approach. Midlife is often a period marked by significant transitions and thus presents an ideal opportunity to change one’s lifestyle and thereby avoid physical and mental frailty in old age. The Santé en action report No. 463 presents the current state of scientific knowledge regarding the health status of this population and analyzes, using examples from France and abroad, the effectiveness of interventions to improve the health of people aged 40–55.

Ages 40–55: A Critical Window for Effective Health Intervention

The period around age 40 is a critical and decisive time for comprehensive action in prevention and health promotion. Yet this has not yet been clearly recognized in France.

In fact, the prevailing approach today is most often based on topics such as tobacco, alcohol, physical inactivity, diet, sleep, etc., each of which is considered independently. Yet these factors interact and must be considered together on a daily basis, throughout the life course and especially at midlife.

The combined effect of health-promoting behaviors at this age yields benefits across all domains: cardiovascular, cognitive, mental, etc. Numerous studies show a link between the presence of one or more chronic conditions in midlife (high blood pressure, diabetes, high cholesterol, obesity) and the onset of dementia, dependency, or frailty as people age.

Indeed, it is during this critical period that risk factors and chronic diseases begin to accumulate. An assessment of the health status of the French population aged 40 to 64 highlights numerous concerning indicators linked to the onset of chronic diseases and disabilities in later life. More than a third of people aged 45–54 already have at least two chronic conditions (including low back pain, obesity, hypertension, migraines, peripheral osteoarthritis, anxiety, and thyroid disorders). This is particularly pronounced among people from lower socioeconomic backgrounds, as the social environment also plays a decisive role in health status and the aging process.

It is therefore necessary to address health determinants “in midlife” to delay the loss of independence among vulnerable individuals; all the more so since care for certain chronic conditions has deteriorated for a segment of the population over the past fifteen years.

Taking action in midlife for oneself and for others

Taking action in midlife also improves the health of other generations, due to the numerous interactions adults aged 40–55 have with younger and older people, foremost among whom are their parents and children. These family pillars also constitute the bulk of the working population, hence the importance of promoting the well-being of this age group, which plays a major role for society as a whole.

The social environment plays a major role in the health status of people aged 40–55

Health status and aging processes are strongly influenced by social factors: biological aging is accelerated among socially disadvantaged individuals or those who have experienced social and psychosocial adversity. By the age of 40, this process of decline is already underway among these populations, who have become more vulnerable due to their social environment. It is particularly important, in terms of prevention, to work toward improving material and psychosocial living conditions starting in childhood.