From the upcoming November 2014 issue of Food, Nutrition & Science.
The majority of U.S. children, including preschoolers, consume caffeine, although intake is on the decline, according to a recent report from the Division of Health and Nutrition Examination Surveys, National Center for Health Statistics, CDC and published in The American Journal of Clinical Nutrition. The report, which looked at caffeine intake in 3,280 children and youth aged 2 to 19 years old who participated in a 24-hour dietary recall as part of NHANES (National Health and Nutrition Examination Survey), found that 71% of U.S. children consumed caffeine on a given day during 2009 to 2010.
When the researchers started this study, published findings on caffeine consumption were available from older national data. Thus, they wanted to provide updated national estimates of dietary caffeine intake in U.S. children 2 to 19 years of age, both in absolute amounts (mg) and in relation to body weight (mg/kg). They chose to look at intakes in both of these ways because of Health Canada’s dietary recommendations on the daily maximal amounts of caffeine intake as well as daily maximal caffeine intake in relation to body weight for older children.
Overall, median caffeine intake was highest in the 12 to 19-year age range at 13.6 mg per day, but younger children consumed caffeine too; reported intakes for 2 to 5-year olds were 1.3 mg per day and for 6 to 11-year olds 4.5 mg per day. Among caffeine consumers, the median intakes were higher at 4.7 mg for 2 to 5-year olds, 9.1 mg for 6 to 11-year olds and 40.6 mg for 12 to 19-year olds. Ten percent of the 12 to 19-year olds exceeded the maximum caffeine intake guideline of 2.5 mg/kg of body weight from Health Canada.
While the Mayo Clinic says up to 400 mg of caffeine a day is safe for most healthy adults (that’s the amount of caffeine found in about four cups of brewed coffee or 10 cans of cola), it is recommended that teens consume no more than 100 mg of caffeine a day (one cup of coffee). And since children may metabolize caffeine differently than adults do, maximum intake for children, according to Health Canada, should be no more than 45 mg/day for children ages 4 to 6, 62.5 mg/day for children ages 7 to 9 and 85 mg/day for children ages 10 to 12 years.
In this study, researchers found no difference in intake between male and females, however, they did find some race differences. Non-Hispanic black children (56%) were less likely to consume caffeine than non-Hispanic white (75%) or Mexican American (72%) children. While there wasn’t any have specific data from the study to explain these differences, several factors could be involved, including different eating habits. In this research, no association between income (examined by poverty income ratio) and caffeine intake was noted.
Caffeine consumption trends were also examined between 2001 and 2010, and during that time, caffeine intake actually decreased for all children. Specifically, among caffeine consumers 2 to 5-years and 6 to 11-years of age, a significant decrease in caffeine intake, by 3 mg and 4.6 mg, respectively was noted. Study author Dr. Namanjeet Ahluwalia and her team presented their findings on dietary sources of caffeine for children at the Experimental Biology meeting in April 2014 and they are still in the process of publishing them. However, there have been other reports that indicate that the chief sources of caffeine in children under 5 are tea, soda, flavored dairy and sweetened grains (e.g. cookies, brownies). Among teens, soda, tea and coffee are the principal contributors to caffeine intake.
“The common prevailing thought is that caffeine intake particularly in teens is high and that it is likely to have increased over the last decade; so our results might be a bit surprising as they did not support this. The factors contributing to downward trend in caffeine intake noted in younger children (under 12 years of age) could not be examined in the study; it is possible that increased awareness on the potential negative effects of caffeine could be involved. In older children (teens), no such trend was noted; intakes remained high in more than 10% of teens and this deserves attention,” says Ahluwalia.
The potential adverse health affects of caffeine are many. Healthy persons may tolerate caffeine well, yet individual responses to caffeine vary drastically. Heavy caffeine intake can cause insomnia, nervousness, irritability and fast heartbeat. Caffeine also has some benefits, including its ability to increase wakefulness, alleviate fatigue and improve focus and concentration. Still, consumption in children is worrisome, and future research is recommended to identify the contribution of specific foods and beverages to caffeine intake as well as the main sources of caffeine in children and teens.
In the U.S., an acceptable level of caffeine intake for children and adolescents has not been set as yet. The American Academy of Pediatrics (AAP) recommends against the inclusion of caffeine in the diet of children. Ahluwalia says individuals and health professionals should try to follow these guidelines.
“Dietary sources of caffeine intake among children should be examined more closely, and newer data from NHANES to be released this year will be available for older children who were the highest consumers of caffeine. Overall, there is a need to continue monitoring caffeine intake (and sources) in children and youth,” adds Ahluwalia.