“You can’t have any or it’ll stunt your growth,” every well-meaning mom with a Starbucks cup says to her curious kid at some point. “You want to be tall like your brother, right?”
Researchers have studied coffee’s role in your height and bone health from two primary angles: whether it limits children’s growth and whether it causes older adults to “shrink.” It turns out, mom wasn’t totally right on this one—but the science is a little messy.
Let’s back up. A 1994 study concluded that postmenopausal women who consumed higher intakes of caffeine (equivalent to 18 ounces of coffee a day) had greater bone loss than women in the low-caffeine group. That’d be a cause for concern given osteoporosis affects 55 percent of American adults over age 50, according to the International Osteoporosis Foundation. (Learn risk factors for osteoporosis here.)
But hang on: Other studies revealed that coffee drinking affected bone health only for participants on low-calcium diets. For example, when 330 boys were separated into three subgroups based on how much coffee they drank, a 2016 study found no significant difference in their height or body weight, regardless of their calcium intake. Another 1994 study found that daily milk consumption offset any effects of coffee on bone density. In other words, the science doesn’t hold up once you consider other factors.
It’s tough to tell if any bone loss from drinking coffee is directly could be caused by your morning java—or if it’s because coffee drinkers in the studies tend to have diets that are overall lower in calcium, which is found in dairy, leafy greens, and beans. Here are top food sources of calcium to boost bone health.
One other thing to note: Drinking caffeine at night (whether coffee or soda) could affect sleep quality, and depriving yourself of precious snooze time can affect your bone mass and development. A study from Pediatrics found that higher caffeine intake was associated with shorter duration of sleep in American middle school students.
Moral of the story? Your 12-year-old should be okay having a pumpkin spice latte at noon, as long as she’s still able to get nine to 11 hours of sleep later, as recommended for children ages 6 to 13 by the National Sleep Foundation. (Here’s how much sleep you need for your age.)
Most researchers agree that following a bone-healthy lifestyle—like exercising, getting adequate sleep, and eating a high-calcium diet as well as foods rich in vitamin D and high-magnesium foods—ensures that you can have your coffee and drink it, too.