“Caffeine stunts growth.”

The belief that caffeine can stunt a child's growth is a widely held notion, yet it lacks scientific backing. This persistent myth likely has a few roots. One theory points to early 20th-century advertising campaigns, particularly by Postum, a coffee substitute, which actively promoted the idea that coffee was detrimental to children's development and could "hamper proper development and growth." These influential advertisements may have ingrained the misconception into public consciousness. Another contributing factor might stem from older research that suggested a link between coffee consumption and osteoporosis or bone loss, leading to the assumption that it could affect height. However, later studies clarified that this perceived link was often due to coffee drinkers consuming less calcium, a vital nutrient for bone health, rather than caffeine itself directly causing bone weakening.

Scientifically, there is no evidence to support the claim that caffeine directly impacts a child's final height. A person's stature is primarily determined by genetics, with various environmental factors like nutrition and general health also playing a role. While caffeine can slightly increase calcium excretion, this effect is considered negligible and easily offset by adequate dietary calcium intake. For example, the calcium in just one tablespoon of milk is enough to counteract the minimal calcium loss from an eight-ounce cup of coffee. A six-year study following adolescents found no correlation between daily caffeine intake and bone growth or density, further debunking the myth.

People commonly continue to believe this myth because it became a piece of "common knowledge" passed down through generations, often as a cautionary tale from parents to children about avoiding coffee. While pediatricians do advise limiting or avoiding caffeine for children, this recommendation is due to other potential effects such as sleep disruption, anxiety, increased heart rate, and acid reflux, not because it will make them shorter. The real concerns about excessive caffeine intake in children are related to these immediate health impacts, not a permanent alteration of their growth trajectory.