Breast Cancer on the Trans Fat Express

Trans fatty acids do not exist naturally in food; they are created when vegetable oils are partly hydrogenated to produce margarine and solid vegetable cooking fats. Trans fats can be found as ingredients in cookies, fried foods and many fast foods, and are added to some liquid vegetable oils to extend their shelf life. Nutritional labels are not required to indicate the presence of trans fats in foods, and they never do.

A recent study of nearly 698 postmenopausal European women suggests that trans fats may be a cause of breast cancer. Women in the study with the highest levels of trans fatty acids in their adipose tissues were 40% more likely than those with the lowest levels to develop breast cancer. Previous studies also have linked consumption of trans fatty acids to an increased risk for heart disease.

Researchers estimate that it would take about two years for a reduced dietary intake of trans fats to be reflected in lower levels in stored body fat.

In related news:

• Phytoestrogens are plant compounds that weakly mimic estrogen, and women whose diets contain foods rich in these compounds appear to have a significantly lower risk of breast cancer.
• Women with higher concentrations of retinoids (vitamin A-related compounds) and carotenoids (antioxidants such as beta-carotene and lycopene) in their breast adipose tissue appear to be less likely to develop breast cancer.
• Several studies suggest that high doses of antioxidants may help prevent cancer by deactivating free radicals that damage DNA. But a team of Dutch researchers believe that free radicals might also have the ability to kill existing cancer cells, and that heavy antioxidant supplementation may be counter productive for people who already have cancer. [Editor: This study seems to contradict Linus Pauling's belief that high doses of the antioxidant vitamin C are helpful against cancer.]

Based on information in: Cancer Epidemiology, Biomarkers & Prevention, Sept 1997; Science News, 10-11-97; American Journal of Clinical Nutrition, Sept 1997; New Scientist, 9-13-97