DEAR DR. ROACH: Is there any truth to the rumor that if you fry with olive oil it is cancer-causing? — H.B.
ANSWER: No.
Not all cancers can be prevented. Some are due to combinations of genes and bad luck, or environmental factors such as air pollution. However, there are activities that can raise or lower cancer risk compared with a general population. Smoking is probably the biggest one. Alcohol also increases risk of many cancers, as does obesity and a sedentary lifestyle.
Diet is also clearly linked to cancer risk. Eating processed meats, charred meats and ultraprocessed foods all have been associated with an increase in different cancer risks (the cancer-causing properties of red meat remain controversial, but are probable, although small).
So, if you fry a processed meat in olive oil, it is still harmful as it relates to cancer risk. However, the olive oil itself, whether consumed raw like in a salad dressing or used to cook, is not carcinogenic (cancer-causing).
Most studies have found that a diet high in fruits and vegetables decreases cancer risk.
What you are frying is more important than what you are frying it in, from the standpoint of cancer risk.
For heart disease, olive oil is high in monounsaturated fat, which is associated with a lower risk of heart disease than other types of fats in oils.
