The diet of preschoolers may influence the risk of breast cancer during adulthood, according to a Boston-based group of investigators.

Dr. Karin B. Michels, of Harvard Medical School, and her associates conducted a study that included 582 breast cancer patients plus a comparison group of 1,569 healthy “controls,” who were enrolled in the Nurses’ Health Study and the Nurses’ Health Study II.

The researchers used a 30-item food frequency questionnaire to obtain early diet information from the mothers of the nurses when they were 3 to 5 years old. The findings are published in the February issue of the International Journal of Cancer.

Women who frequently consumed French fries at preschool age had an increased risk of breast cancer. The increased risk of breast cancer for one additional serving of French fries per week was 27 percent. Consumption of whole milk was linked to a slightly decreased breast cancer risk - for each additional glass of whole milk per day, the risk decreased by 10 percent. No association was found between nutrient levels and the risk of breast cancer.

“For us breast cancer researchers this indicates that we are on the right track to research earlier periods of a woman’s life than we previously have done in the search for breast cancer risk factors,” Michels told Reuters Health. “It seems that childhood diet may be important and maybe even more important than an adult woman’s diet with respect to later life risk of breast cancer.”

However, Michels cautioned against over-interpreting the results. “First of all, we would like to see these findings confirmed in other studies,” she said. “Secondly, this was a case-control study and the mothers of the nurses knew whether their daughters had developed breast cancer or not, which may or may not have influenced their reporting, but we must not lose sight of this fact.”

SOURCE: International Journal of Cancer, February 2006.