Avoiding drinking cola - both regular and diet - may prevent bone loss and osteoporosis, according to new research from the longest-running population study in history.
Colas contain phosphoric acid, which has been shown to interfere with calcium absorption, and may contribute to calcium loss from the bone by raising blood acidity. Bone then contributes calcium to the blood to maintain a normal acid/alkaline balance in the blood.
Over the past half century, the Framingham Heart Study has been the source of countless insights into the effects of various dietary and lifestyle factors on cardiovascular and other diseases. This latest research examined the association between drinking carbonated beverages—overall and divided into cola and non-cola types—and bone mineral density in more than 2,500 men and women.
Bone mineral density was measured in the spine and at three hip sites in 1,413 women and 1,125 men. Dietary intake of cola and other carbonated beverages was assessed by food frequency questionnaires. Participants were followed over a period of thirty years, from 1971 to 2001. Those taking drugs that affect bone mineral density (such as bisphosphonates, selective estrogen receptor modulators, or calcitonin) were excluded from the study.
Women who drank cola on a daily basis had significantly lower bone mineral density in the hip than did women who only drank cola once a month. No relation between cola intake and bone mineral density was found in men. No significant relations were found between bone mineral density and non-cola beverages. The mean intake of soft drink was six servings a week for the men and five for the women with cola the most popular. The average daily intake has been increasing significantly over the course of the study, so today's cola intake is significantly larger than in 1986, the midpoint of the study.
Osteoporosis and bone fractures are a major public health problem, affecting 40% of women and 13% of men in their lifetimes. In recent years, soft drink consumption has increased, displacing milk and other nutrient-rich beverages in the diet. As an increasing proportion of the population reaches their sixties and seventies, these dietary trends could have a serious impact on the risk of fractures and related disability.
Women who are concerned about osteoporosis should avoid cola beverages, and instead drink water, milk, and fruit juice.
Am J Clin Nutr 2006;84:936–42.