The differentiation of key metabolic systems that occurs during
intrauterine life is greatly influenced by environmental nutritional
conditions, which in turn are related to maternal nutritional
status. In postnatal life, childhood exposure to slow-acting
environmental factors, primarily through the diet, will begin to
condition adult susceptibility to diseases. Examples of these
dietary factors are intake of saturated fat, sodium, calcium, etc.
For example, bone calcium accumulation during childhood and
adolescence will be a major determinant of risk of osteoporosis
later in life. Similarly, a high intake of saturated fat during
childhood may promote the process of atherosclerosis in persons with
genetic susceptibility, thus accelerating the clinical
manifestations of coronary heart disease in adult life.
These findings, although still not completely clarified, constitute a
significant opportunity for preventive intervention. While
preventive intervention in adult life may reduce risk, this is
usually difficult and results are often limited. One example would
be obesity. In contrast, interventions early in life, aimed at
reducing these early risk factors, could potentially result in major
reductions in the incidence of several diseases of adults.