Question

The paper "Prospective Randomized Trial of Low Saturated Fat, Low Cholesterol Diet During the First Three Years of Life" (Circulation [1996]: \(1386-1393\) ) describes an experiment in which "1062 infants were randomized to either the intervention or control group at 7 months of age. The families of the 540 intervention group children were counseled to reduce the child's intake of saturated fat and cholesterol but to ensure adequate energy intake. The control children consumed an unrestricted diet." a. The researchers concluded that the blood cholesterol level was lower for children in the intervention group. Is it reasonable to conclude that the parental counseling and subsequent reduction in dietary fat and cholesterol are the cause of the reduction in blood cholesterol level? Explain why or why not. b. Is it reasonable to generalize the results of this experiment to all children? Explain.

Short answer

a. Yes, it's reasonable to conclude that the parental counseling and subsequent reduction in dietary fat and cholesterol are the cause of the reduction in blood cholesterol level, assuming no other major changes were made in the children's lifestyle. b. While the research provides useful insights, the results should not be generalized for all children without taking into consideration the constraints of the study.

Step-by-step solution

Evaluate the Causality

From the given data, it's shown that the children who were part of the intervention group had lower blood cholesterol levels. This intervention group's specific change is that they had guidance from counseling to consume a diet low in cholesterol and saturated fat. Therefore, it's reasonable to conclude that there is a cause-and-effect relationship between the change in diet and cholesterol levels. However, this conclusion naturally holds assuming that all other conditions in the lives of the children remain consistent and no other changes were made that could significantly impact cholesterol levels.

Evaluate the Generalizability

Research studies like this, while providing valuable insights, are conducted under controlled conditions and with specific groups of subjects. So the generalization of the results should always be made with caution. In this case, the sample consists of infants, from only one geographic location and up to 3 years old. Therefore, it’s not completely justifiable to extend these results to other age groups, any other geographic locations or with different dietary habits, until similar studies verify the results in those contexts.