"Good parent-child bonds may be necessary to enforce eating, sleeping and activity routines," said researcher Assistant Professor Matthew A. Andersson at Baylor University in Texas, US.

The study found that if the parent-child relationships are strained or abusive, meals may be less coordinated among the family, and children are more likely to eat sugary or high-fat foods as snacks, even in place of proper meals. 

Sleep and activity routines could also become irregular, keeping children from developing healthy lifestyles and social and emotional skills necessary for successful ageing.

On the other hand, good parent-child bonds in economically disadvantaged homes, might promote health, but do not seem to lessen the negative impact of low socio-economic status as the children age, Andersson said. 

Parents with less education and fewer financial advantages are more apt to threaten or force obedience rather than have constructive dialogue, and that may lessen warm relations. 

In addition, disease rates or inflammation among those children when they become adults have been linked strongly to abuse, mistreatment or lower levels of parental warmth.

"Without adequate parent-child relationship quality to match, socio-economic advantage during childhood may not offer much protection against major chronic disease as children become adults and reach middle age," Andersson stated.

In the study, good health at mid-life was defined as being free from 28 possible conditions -- cancer, circulatory or respiratory disease, endocrine diseases, nervous system diseases, infectious and parasitic diseases, skin and digestive disease and musculoskeletal conditions.

For the study, the team analysed data on disease or poor health of middle-aged adults. They surveyed 2,746 respondents aged 25 to 75 in 1995 about their childhood treatment by parents. 

Surveys were conducted again nearly 10 years later, with 1,692 of the individuals taking part. 

The follow-up analysis revealed that childhood abuse continued to undermine any protection from disease when linked to childhood socio-economic advantage, the researchers concluded, in the paper published in the Journal of Health and Social Behavior.