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

Each weekly serving of French fries girls consumed between ages 3 and 5 increased their risk of developing breast cancer as adults by 27 percent, according to researchers at Brigham and Women's Hospital and the Harvard School of Public Health.
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The finding of a correlation between French fries and breast cancer does not necessarily point to a cause-and-effect relationship between the two, however.

Michels speculated the French fries may be implicated in breast cancer because they are prepared in fats that are high in harmful trans-fatty acids and saturated fat.

It's important to note that this is a stand-alone study, and has not been verified by any other research groups. But I still think it's interesting data.