Good news: Trans fats are linked to breast cancer risk. Why is this good? Two reasons. One, it unravels another bit of the mystery surrounding why people get cancer. Two, it gives us more reason to ditch trans fats from our diets.

We already know trans fats are artery-cloggers. That's why they're being phased out of various foods. Now researchers suspect they cause breast cancer too.

Women with the highest blood levels of trans-fats had about twice the risk of breast cancer compared to women with the lowest levels, say the findings of a study published in the American Journal of Epidemiology. We'd all be wise then to limit our consumption of processed foods, the source of trans-fatty acids. Trans-fats are mostly found in cooking fats, baked goods, snacks, and a variety of other prepared foods.

Interestingly, this study found women with higher levels of omega-3 fatty acids -- the good stuff, found in fish such as salmon, walnuts, and leafy green vegetables -- were not any less likely to have breast cancer. So the mystery continues. And all we can do is the best we can, with the information we have. See how good you're doing with this AOL Body cancer quiz.