Children who drink non–cow’s milk may be shorter than their peers, according to a study published in The American Journal of Clinical Nutrition.

Researchers have found links between lower height and non–cow milk products like those made of soy, rice or almond.

“Our findings may be important for parents, dieticians and physicians when considering the optimal type of milk for children to consume,” authors wrote.

Previous studies found ties between greater height and drinking cow’s milk, so researchers set out to see if other types of milk, which have been gaining in popularity, also were associated with growth.

They studied 5,034 children ages 24–72 months, of whom 92% drank cow’s milk daily and 13% drank non–cow’s milk.

They found children were 0.4 centimeters (cm) shorter than average for their age for every daily cup of non–cow’s milk they drank and 0.2 cm taller than average for each daily cup of cow’s milk.

On average, a 3–year–old drinking three cups a day of cow’s milk was 1.5 cm taller than a 3–year–old who drank three cups of non–cow’s milk daily. Those drinking both types of milk were shorter than average.

Researchers said the height difference may be attributed to non–cow’s milk having less dietary protein and fat. There are about 16 grams of protein in two cups of cow’s milk compared to 4 grams in almond milk, according to the study.

“The lack of regulation means the nutritional content varies widely from one non–cow’s milk product to the next, particularly in the amount of protein and fat,” author Jonathon Maguire, MD, MSc, said.