Currently, about 30% of the beverages Americans consume are carbonated beverages. This level of consumption surpasses that of all other beverages, including milk, coffee, and water. This percentage has been steadily rising since the 1970's, and has serious potential to affect our health. It is widely accepted that increased consumption of sugar-sweetened beverages is related to America's rising obesity rates. It has also been said that drinking carbonated beverages reduces bone mineral density and decreases calcium absorption.
The Framingham study, performed in 2006, investigated the relationship between carbonated beverage consumption and bone mineral density. They found that drinking cola every day resulted in a significant increase in bone fractures in girls younger than 17. A positive relationship between reduced bone mineral content and carbonated beverage consumption in teenage girls has also been found, especially if the girls are physically active. Other studies have found a similar relationship between cola consumption and bone density in young men.
While these studies have focused on the consumption of all carbonated beverages, cola beverages have been the most implicated. It is believed that drinking high amounts of cola may limit calcium absorption because of its high phosphorous content. This may not be the case for other carbonated beverages that do not contain high levels of phosphorous (all non-cola flavored sodas, as well as carbonated flavored waters). The consumption of caffeine has also been associated with the reduction of bone mineral density, and may contribute to these findings. Caffeine can be found in Coke, Diet Coke, Pepsi, Diet Pepsi, Tab, Mountain Dew, Dr. Pepper, and Sunkist. If you'd like to know the amount of caffeine in your soft drink, check the nutritional label.
It is also possible that consumption of carbonated soft drinks replaces the consumption of milk, limiting calcium intake. This might be a problem especially for children and teenagers, for we build 85-90% of our bone before the age of 20. Maximizing peak bone mass during childhood and adolescence is important for preventing osteoporosis. Replacing milk with soft drinks of any kind might interfere with this.
Considering this evidence, it is important to reduce or eliminate the number of carbonated beverages we drink on a daily basis, especially if we drink lots of cola. Be sure to encourage the consumption of milk and water in children and adolescents in place of soda whenever possible.
Kinney MA. (2002) Does consumption of cola beverages cause bone fractures in children? Mayo Clin Proc; 77:1005-1006
Tucker KL, Morita K, Qiao N, Hannan MT, Cupples LA and Kiel DP.(2006) Colas, but not other carbonated beverages, are associated with low bone mineral density in older women: the Framingham Osteoporosis Study. Am J Clin Nutr. 84;936-42
Kristensen M, Jensen M, Kudsk J, Henriksen M and Mulgaard C. (2005) Short-term effects on bone turnover of replacing milk with cola beverages: a 10-day interventional study in young men. Osteoporosis Int 16: 1803-1808