Differential effects of casein versus whey on fasting plasma levels of insulin, IGF-1 and IGF-1/IGFBP-3: results from a randomized 7-day supplementation study in prepubertal boys

What Was Tested

This randomized controlled trial paper looks at IGF-1 LR3.

It is, however, unknown which components in milk are responsible for milk's growth-stimulating effect.

Who Took Part

By PubMed's age tags, the people studied were children, men only.

How the Study Was Run

In design terms this was a randomized and double-blind study.

Random assignment meant chance, not the researchers, decided who got IGF-1 LR3 and who got the comparison, which limits bias.

As a double-blind IGF-1 LR3 study, the assignments were hidden from both participants and investigators until the end.

To get closer to the identification of which components in milk that stimulate growth, the researchers have performed an intervention study with 57 eight-year-old boys in which the researchers examined the effects of the two major milk protein fractions, whey and casein, and milk minerals (Ca and P) in a 2 x 2 factorial design on IGFs and glucose-insulin metabolism.

The amounts of whey and casein were identical to the content in 1.5 l skim milk.

What Was Measured

Topics PubMed links to this paper include Calcium, Calcium, Dietary, Caseins, Dietary Proteins, Insulin, Insulin-Like Growth Factor Binding Protein 3 and Insulin-Like Growth Factor I.

What This Means in Plain Language

The paper is a randomized and double-blind study of IGF-1 LR3.

The abstract goes on to report its results in about 5 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2009 (European journal of clinical nutrition), a journal based in England.

More context: the IGF-1 LR3 compound page, all human trials.