Diet during preschool may be associated with the risk of breast cancer in adulthood, according to findings published in the February issue of the International Journal of Cancer.

Dr. Karin B. Michels, of Harvard Medical School, Boston, conducted a case-control study including 582 breast cancer patients and 1569 healthy controls who had been enrolled in the Nurses' Health Study and the Nurses' Health Study II. They used a 30-item food frequency questionnaire to obtain data on the childhood diets of the nurses at ages 3 to 5 years from the participants' mothers.

Women who had frequently consumed French fries at preschool age had an increased risk of breast cancer. The odds ratio (OR) for breast cancer for one additional serving of French fries per week was 1.27. Consumption of whole milk was linked to a slightly decreased breast cancer risk (OR per additional glass of whole milk/day = 0.90). No association was found between intake of any of the nutrients calculated 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," Dr. 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."

Dr. Michels cautioned against overinterpreting the current findings. "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."