Scientists at the University of Illinois have found that consuming repeatedly reheated cooking oil may promote the growth of cancer cells.
The study, which was published Cancer Prevention Research journal, says repeatedly reheated oil may act as a toxicological trigger that promotes tumour cell proliferation and metastases.
The researchers experimented with two groups of mice fed with fresh and thermally abused soybean oil respectively over a space 16 weeks.
They simulated late-stage cancer by injecting 4T1 cancer cells−a reportedly aggressive and wide-spreading form of the disease−into each mice group.
Thereafter, they reported that the primary tumors in the mice that consumed thermally abused oil had more than four-fold metastatic growth compared to their counterparts.
“There were twice as many tumors in the lung, and they were more aggressive and invasive,” said lead researcher William Helferich, food science professor.
“I just assumed these nodules in the lungs were little clones but they weren’t. They’d undergone transformation to become more aggressive.
“The metastases (disease spread) in the fresh-oil group were there, but they weren’t as invasive or aggressive, and the proliferation wasn’t as extensive.”
Commenting on the research results, Nicki Engeseth, co-researcher of the study, said: “As the reheated oil degrades, polymer molecules also accumulate, raising nutritional and toxicological concerns.
“When repeatedly reused, triglycerides are broken apart, oxidizing free fatty acids and releasing acrolein, a toxic chemical that has carcinogenic (cancer-causing) properties.”
Although they agreed that there are still ongoing efforts to understand the specific catalysts for tumor growth in such cases, the researchers remained convinced that diet plays a role in that regard.
