Earlier study showed that substances called heterocyclic amines (HAs) found in cooked meat and fish at high temperatures increased risk of breast cancer in mice. During recent research, Swedish researchers said that HAs don't appear to boost a woman's risk of developing breast cancer after menopause. 

In this study researchers examined whether HA consumption was related to breast cancer, and whether omega-6 PUFA intake played a role in this relationship, in women enrolled in the Malmo Diet and Cancer study. 

Researchers added that study showed that combination of the low quantity of these substances with high consumption of omega-6 polyunsaturated fatty acids (PUFAs), which are found in most types of vegetable oil, may increases risk of breast cancer in postmenopausal women. 

This research was done by Dr. Emily Sonestedt, of Lund University, Malmo, and her colleagues. 

For this research, researchers analyzed the data collected from 11,699 women 50 and older. Researchers followed study subjects about 10 years. During the study 430 women were diagnosed with breast cancer. 

Analysis of data showed that women who consumed the most HAs were at no greater breast cancer risk than those who consumed the least. But women who had low HA consumption along with high omega-6 PUFA were at higher risk of developing breast cancer.

Sonestedt and her team said that the interaction in the present study between omega-6 PUFAs and HAs is not easily explained, and points toward the importance of examining the impact of food patterns rather than the influence of single dietary factors.

Researchers concluded that a diet "very high in omega-6 PUFA may promote breast cancer development."