In his posting, Dr. Saint Cyr specifically addressed how childhood factors play a large role in future health. This can not be emphasized enough!

The background research on early child development for this WHO report (see Early Child Development: A Powerful Equalizer) was led by Dr. Clyde Hertzman, Director of the Human Early Learning Partnership (H.E.L.P.). Some of his findings on the topic were summarized in a recent issue of the BMJ.

What we learn is that not only do factors like quality of time and care provided by parents and the physical conditions of the child’s surrounding affect developmental outcomes, but also safe neighbourhoods and decent housing. While these factors may not appear all that dramatic and unexpected, their effects are far reaching.

Early (i.e. under age 5) child development has been unequivocally demonstrated to influence obesity and stunting, mental health, heart disease, competence in literacy and numeracy, criminality, and economic participation, to name but a few dimensions.

This importance of early childhood development is due in large part to a multitude of sensitive periods in brain development as illustrated for the first seven years of life in the following graph. The dark grey section on the left represents the first five years, which is when sensitivity is highest:

Dr. Hertzman explains (4:08 minute video) the importance of these periods with an example: “The visual systems are connecting to the deep structures in the brain that are associated with emotional control; that means that children who have a consistent set of human faces that they see early on in life going through a wide range of emotions develop the neurobiological ability to decode emotion and to develop a sense of belonging. Those children who are neglected or grow up in environments that are violent or emotionally barren develop a completely different style of coping early on in life and a different set of biological connections which do not work so well adaptively later on.”

Teenage issues and adult problems that can now be tracked back to the first five years of life include not only hypertension, depression, diabetes and even memory loss but dysfunctional behaviors too.

In essence, writes Dr. Hertzman and his team, “The environmental conditions to which children are exposed in the earliest years literally “sculpt” the developing brain.” Much research is ongoing to understand the biological, chemical, hormonal and other pathways that can explain this.

In the meantime, enough is already known about the first five years of life and how this period clearly impacts multiple other “determinants of health” such as education and employment and income and social status.

As such, perhaps we can say indeed say that determinant #6 is more important than the others… So why don’t we all go and find a book to read to a child we know?