A cup of non-cow's milk a day was associated with 0.4 centimeters lower height than average
Children who drink dairy alternatives are shorter than their peers who drink cow's milk, according to a new study.
The study, published in the American Journal of Clinical Nutrition, found that each daily cup of non-cow's milk consumed was associated with 0.4 centimeters (0.15 inches) lower height than average for a child's age.
The study was a cross-section involving 5,034 healthy Canadian children ranging in age from 2 to 6 years old. The subjects were on average 38 months of age, with 51% being male, and were recruited from nine family and pediatric health-care practices from December 2008 to September 2015.
Of those participating, about 5% drank exclusively non-cow's milks, and about 84% drank only cow's milk; about 8% drank both and about 3% drank neither.
"We found that children who are consuming non-cow's milk like rice, almond and soy milk tended to be a little bit shorter than children who consumed cow's milk," said Dr. Jonathon Maguire, the study's lead author and a pediatrician and researchers at St. Michael's Hospital in Toronto.
"For example, a 3-year-old child consuming three cups of non-cow's milk relative to cow's milk was on average 1.5 centimeters shorter [...] That's over half an inch difference, which Maguire said is "not a tiny difference when you're 3 years old."
The research also suggests the discrepancy varies depending on individual consumption.
"It's not like if you're not consuming cow's milk, you're a little shorter. It's more like if you are consuming non-cow's milk, with each cup that a child consumes, that child on average appears to be a little bit smaller, a little shorter. That's a bit surprising."
Researchers have yet to establish if children's height correlates with height going into adulthood.