Doctoral dissertation research investigated how the family environment in childhood affects health in midlife. The study showed that only children have a more unfavourable profile of risk factors for cardiovascular disease throughout their lives. Furthermore, exposure to parental smoking had a negative impact on cardiovascular health and cognitive performance even in middle age.
Cardiovascular disease and cognitive decline remain leading causes of morbidity and mortality worldwide. Several risk factors have been identified for these diseases, but they do not fully explain the disease burden.
MD Jukka Pihlman, specialist in internal medicine and a doctoral researcher at the University of Turku in Finland, investigated in his doctoral dissertation whether family-related factors experienced in childhood affect health even decades later.
The research data were derived from the population-based Cardiovascular Risk in Young Finns Study, which has followed the participants from childhood for over 30 years.
The participants’ health was studied by examining cardiovascular risk factors, the structure and function of the heart using ultrasound, early signs of atherosclerosis, i.e. hardening of the arteries, and cognitive performance in middle age using standardised tests.
Passive smoking has an impact even in middle age—as does being an only child
The key research findings showed that exposure to parental smoking during childhood was linked to changes in heart structure and poorer cognitive performance in middle age. In particular, episodic memory, i.e. autobiographical memory, as well as working memory and learning were weaker in individuals who had been exposed to tobacco smoke during childhood.
Furthermore, the study found that the number of siblings was associated with risk factors for cardiovascular and metabolic diseases throughout the course of life. Only children had a less favourable profile of risk factors for cardiovascular disease even in childhood, such as a higher body mass index and lower levels of physical activity. Furthermore, they were found to have higher rates of obesity and high blood pressure in adulthood.
The research provides new information about how the effects of family environment may extend considerably further than previously understood:
“Although the harmful effects of passive smoking during childhood are well known, the results of our study suggest that these effects may still be evident in the structure of the heart and cognitive function in middle age. Furthermore, the study shows that family size and the number of siblings may be associated with later cardiovascular and metabolic health, regardless of several other known socio-economic and lifestyle factors,” Pihlman states.
The findings highlight the importance of protecting children and young people from exposure to second-hand smoke. They also suggest that factors relating to family structure could be utilised in identifying children and young people who may be at a higher risk of developing health problems later in life.
The study reinforces the view that the foundations of people's health are laid in early childhood and that preventive measures targeting early-life circumstances may potentially reduce the risk of cardiovascular disease and cognitive decline later in life.
