R. Rani and V.K. Kansal of National Dairy Research Institute in Haryana, India tested both soybean oil and cow ghee in female rats that were at higher risk of mammary cancer because they were exposed to carcinogen 1,12-dimethylbenz(a)anthracene (DMBA).

Two groups of rats were fed a diet either with 10% soybean oil or cow ghee for 44 weeks. At five weeks, rats received 39mg per day of DMBA through oral intubation to induce cancer.

The researchers found among the two groups of rats receiving DMBA, the rats on soybean oil had more tumors, compared with those on cow ghee, 65.4% versus 26.6%.  The tumor weight was also higher in soybean oil users than the cow ghee users, 6.18h versus 1.67h.

The tumor latency was 23 weeks for rats on soybean oil and 27 weeks for rats on cow ghee.

Also the researchers found carcinogenesis progressed more rapidly in rats on soybean oil than those on cow ghee.

Soybean oil has high amounts of omega-6 fatty acids, which some researchers believe may promote growth of tumors.  Patients who receive alternative cancer treatments may be required not to use soybean oil and corn oil because of their potential negative impact on the risk of cancer.

From the May 31, 2011, Prepared Foods' Daily News.