Casein, whey and how cow's milk affects children's growth
What it found
Cow's milk appears to boost height growth in children, but scientists do not yet know which parts of milk cause this.
Whey protein may have a slightly higher quality than casein based on its amino acid makeup.
What they found
Studies in people
Milk and height growth
Studies in children show that drinking cow's milk is linked to greater height growth. This was seen in both low-income and high-income countries.
Whey and muscle mass
Research, mostly from sports medicine, suggests whey protein may help build muscle. It is not clear whether whey improves body shape more than other milk proteins.
Other findings
Whey versus casein quality
Some measures based on amino acid makeup rate whey protein as slightly higher quality than casein. Both are considered high-quality cow's milk proteins.
How milk might work
Milk may stimulate growth by raising levels of a hormone called insulin-like growth factor-I. It might also increase insulin release.
What the authors conclude
- They say there is strong evidence that milk boosts height growth in children.
- They note the exact way milk does this is not yet clear and call for more trials to find out which milk components are responsible.
- They point out that the effects of milk on height and adult size could have both positive and negative long-term consequences.
How it was done
Many countries recommend that children drink cow's milk, and studies suggest it helps them grow taller. Scientists wanted to find out which parts of milk might be responsible for this effect.
The authors looked at past observational and intervention studies on milk drinking and growth in children. They examined research from both low-income and high-income countries. They also reviewed work on milk proteins like whey and casein.
What it can’t tell you
- We summarised it from the abstract only.
- This work pulls together many different studies rather than running a new trial.
- It cannot prove exactly which part of milk causes growth or how it works.
- The long-term effects of extra height from milk drinking are also unknown.
Who paid
- Authors work at
- University of Copenhagen, Denmark
The paper
- Title
- Milk and growth in children: effects of whey and casein
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Mølgaard C, Larnkjær A, Arnberg K, Michaelsen KF (2011). Milk and growth in children: effects of whey and casein. Nestle Nutrition workshop series. Paediatric programme. doi:10.1159/000325576PubMed 21335991DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error