Safflower (Carthamus tinctorius) is an annual plant with yellow flowers. Safflower oil is extracted from the seeds. Safflower oil is a polyunsaturated oil consisting primarily (76%-82%) of the omega-6 fatty acid linoleic acid, It also contains some oleic acid and palmitic acid. Safflower oil has been shown to have pro-inflammatory properties. Linoleic acid has been shown to enhance the invasion and peritoneal metastasis of gastric carcinoma cells.
Safflower oil has the highest proportion of linoleic acid of all common cooking oils. Linoleic acid is converted into arachidonic acid in the body.
Breast cancer-related effects of consuming safflower oil
In addition to cancer cell studies, numerous experiments using either carcinogen-induced tumors or transplanted mammary tumors in mice have demonstrated that linoleic acid and arachidonic acid promote mammary tumor development. Daughter mice of female mice fed a high linoleic diet are more prone to develop mammary tumors.
One study reported that women with a specific genotype (ALOX5AP −4900 A>G polymorphism) who consumed a significant amount of linoleic acid in their diets had an increased risk of breast cancer. Another study found increased breast cancer risk among women cooking primarily with high linoleic acid vegetable or corn oil compared to women using olive or canola oil.
Women with breast cancer have been found to have higher levels of omega-6 in their breast tissue than similar women without breast cancer. Several studies have found that lower dietary omega-6/omega-3 ratios are associated with reduced risk of breast cancer. Consuming safflower oil would tend to increase the ratio for most women because of its high omega-6 content.
Note that while we are continually searching for new evidence specifically concerning this food, there is not much interest in it among breast cancer researchers, so few studies are available.
Below are links to recent studies concerning this food. For a more complete list of studies, please click on safflower oil.