A study examining the role childhood diet plays in breast cancer has found an association between eating French fries regularly during preschool years and developing breast cancer as an adult.

A study of American nurses found that girls between the ages of 3 and 5 who frequently consumed French fries increased their risk of developing breast cancer as adults by 27%, according to researchers at Brigham and Women's Hospital and the Harvard School of Public Health.

The association was not found with potatoes prepared in other ways.

The finding is the first of its kind and must be confirmed by other studies, said lead author Karin Michels, an associate professor at Harvard Medical School and a clinical epidemiologist at Brigham and Women's Hospital in Boston. "This is something nobody has really looked at before. It is really new," she said, adding, "It could be due to chance."

She speculated that French fries might be implicated in breast cancer because they were prepared in fats high in harmful trans-fatty acids and saturated fat.

The dietary survey examined the childhood eating habits of participants in the Harvard Nurses' Health Study. To obtain information about what adult women had eaten as preschoolers, the researchers asked the mothers of participants in the nurses study to complete questionnaires asking how often their daughters had eaten 30 different food items.

The researchers analyzed data gathered in 1993 from 582 participants with breast cancer and 1,569 women without breast cancer. The participants were born between 1921 and 1965, so their mothers were being asked to recall information from decades earlier. Michels noted the recollections might have been unreliable, especially when made by mothers who already knew their daughters had breast cancer.

Consumption of whole milk was associated with a slightly decreased risk of breast cancer, though most of the milk consumed during those decades was whole milk, Michels said.