Does a higher protein intake increase cardiac function in healthy infants?

There is compelling evidence that the type of nutrition received in the early periods of an organism’s development may affect the structure and function of body tissues later in life.

It is understood that protein intake may play a key role in modulating body mass and function of various organs and systems – this is because protein increases body mass, which in turn increases the load on the organs. However, until recently, there had been little research into the specific effects of protein ingestion in healthy infants.

In the past, the relationship between protein intake and cardiac function had only been documented in situations where one or the other was grossly altered such as via malnutrition or heart failure. The European Childhood Obesity Project Group, which is made up of researchers based at university hospitals and health institutes in Spain, Germany, Poland and Italy, recently published research into the issue, following secondary analysis from a clinical trial undertaken in Spain between 2004 and 2006. The aim of the recent research was to assess the effect of different protein intakes during the first year of life on cardiac mass and function once the child had reached the age of two.

Protein intake during infancy is one of the key nutritional factors affecting obesity risk and other health consequences later in life. The study tried to determine whether the protein supplied by milk formula during early fast-growth periods could induce changes in cardiac structure, as evidenced by changes in cardiac mass measured by echocardiography.

A sample of infants were divided into three groups: a third were fed a high protein formula; a third were fed a lower protein formula and the remaining third were breastfed. The infants were given blood tests, echocardiographic assessments, blood pressure measurements as well as general recordings of weight, length and head circumference at six months of age, and again when they were two.

While there were no significant variations in weight and height between the three groups, the group receiving high protein formula had significantly higher BMI scores at two years of age compared to those receiving low protein formula. Results also showed cardiac function parameters were modulated by protein intake, whereas cardiac mass did not differ between the feeding groups.

Overall, the study shows that a higher protein intake in infancy is associated with a higher cardiac systolic function at two years of age. An increase in total body surface implies an increase in the cardiac output to fulfill the organism’s higher oxygen processing requirements.

Higher body weight implies higher energy expenditure and energy expenditure is tightly related to cardiac output. In summary, the study demonstrated that a moderate increase in protein intake during the first year of life is associated not only with higher BMI scores but also higher cardiac function parameters at two years of age.

However, no changes were discovered in cardiac mass at this early stage of the child’s development. Further investigation is warranted to elucidate the clinical applications of this nutritional programming effect in infancy.