The reason that trans fats are so bad for you is because they promote oxygen free radicals—molecules that cause damage to your cells and DNA, damage that can lead to cancer. Trans fats also encourage inflammation, which, in turn, creates more oxygen free radicals. Chronic inflammation has been identified as a key factor in the initiation and progression of breast cancer.

All these ill effects add up to a high probability of developing breast cancer. Research has found that women with the highest amounts of trans fats in their bodies have a 40 percent increased risk. And if that isn’t bad enough, cancer isn't the only disease provoked by chronic inflammation. It’s thought to play a big role in many degenerative diseases, including heart disease, the #1 killer of American men and women.

Omega-6 Fatty Acids

Fats are made up of smaller units of molecules called fatty acids. Omega-6 fatty acids are needed by your body to function properly. But if you eat too much of them, they increase your risk of breast cancer. Studies have found that women with the highest amounts of omega-6 fatty acids in their bodies have a 69 percent increased risk of breast cancer. If you have breast cancer, eating large amounts of omega-6 fatty acids can make your prognosis—and your chance of survival—worse. These fatty acids increase the likelihood that your cancer will metastasize, spreading to other parts of your body.

Oils High in Omega-6 Fatty Acids
Borage
Commercial salad dressings
Corn
Cottonseed
Grape seed
Margarine
Mayonnaise
Peanut
Primrose
Safflower
Sesame
Soybean

Protective Fats

Not all fats are bad for you. There are some that are highly protective and health-promoting. Omega-3 fatty acids found in flax seeds and flax oil is considered the healthiest type of fat that you can eat.