A new prospective study has reported that consumption of trans fat and saturated fat both are associated with reduced breast cancer-specific survival. Trans fats from partially hydrogenated oils are found in many commercially prepared and processed foods, including French fries and doughnuts, baked goods and margarines.
Saturated fats are found primarily in meats and dairy foods (fatty beef, lamb, pork, poultry with skin, lard, whole milk, cream, butter, cheese) and baked and fried foods containing palm oil, palm kernel oil or coconut oil.
The study was designed to investigate the relationship between post-diagnosis diet and mortality. Not much is known about the effects of diet in breast cancer survivors. The study included 4,441 women with a history of invasive breast cancer diagnosed between 1987 and 1999 who had not experienced a recurrence. A 126-item food frequency questionnaire was used to assess diet. A total of 137 of the participants died from breast cancer during the first seven years after enrollment in the study. The analyses were adjusted for factors associated with breast cancer risk and prognosis at diagnosis, during the time period between diagnosis and diet assessment, and at follow-up.

Study results

Women in the highest fifth of consumption of trans fat were found to have 1.8 times the risk of dying from any cause compared to lowest fifth. Study participants in the highest fifth of consumption of saturated fat had 1.4 times the risk of dying as those in the lowest fifth. Both types of fat increase cholesterol and risk of heart disease and stroke. Results were similar for risk of dying specifically from breast cancer, however they did not reach statistical significance. The authors conclude that lower intake of trans fat and saturated fat after diagnosis of breast cancer is associated with improved survival.
Please see our article on how to optimize your breast cancer diet for information on what to eat during all stages of treatment and recovery.