High dairy in childhood linked with cancer risk

NEW YORK (Reuters Health) - Children who consume high levels of diary products may have a greater risk of developing colorectal cancer in adulthood, study findings suggest.

Among nearly 5,000 individuals followed for an average of 65 years, those who grew up in families reporting the highest levels of dairy consumption -- nearly 2 cups per day -- had close to three-times the risk of colorectal cancer compared with those from families reporting the lowest intake, Dr. Jolieke C. van der Pols and colleagues report.

The level of milk consumption in the high-diary group was similar to the estimated average daily intake of children in the United States, van der Pols, of the University of Queensland, Brisbane, Australia, and colleagues noted.

Links between colorectal cancer risk and childhood exposure to dairy products have not been previously evaluated, the researchers said.

Using data from a study of weekly food consumption in families living in England or Scotland from 1937 to 1939, the researchers estimated the daily dairy intake ranged from less than half a cup at the lowest to nearly 2 cups at the highest. Nearly all, 94 percent, of the diary produces came from drinking milk, they report in the American Journal of Clinical Nutrition.

Among the 4,374 individuals still available for follow-up between 1948 and 2005, the investigators identified 35 registrations and 41 deaths from colorectal cancer.

An increased risk of colorectal cancer among those who consumed the highest amounts of dairy during childhood was still seen after the investigators adjusted the data for potentially influential factors such as meat, fruit, and vegetable consumption; and socioeconomic status.

However, van der Pols' group cautions that more complete life-course assessments comparing dairy intake with related dietary and lifestyle factors must be completed before definitive conclusions can be made for dairy intake in childhood.

SOURCE: The American Journal of Clinical Nutrition, December 2007.