Evidence Hub

Dietary polyunsaturated fatty acids and cancers of the breast and colorectum: emerging evidence for their role as risk modifiers

H Bartsch, Jagadeesan Nair, Robert Wyn Owen

Carcinogenesis, 1999

479 citations

Abstract

The hypothesis that a high-fat diet promotes the development of postmenopausal breast cancer is supported by international data showing a strong correlation between fat intake and breast cancer rates and a modest positive association with high-fat diet in case-control studies. Dietary fat intake was found to be unrelated to the risk of breast cancer in cohort studies. In view of these conflicting findings it has been difficult to make nutritional recommendations for the prevention of breast cancer. Studies in animal models and recent observations in humans, however, have provided evidence that a high intake of omega-polyunsaturated fatty acids (PUFAs), stimulates several stages in the development of mammary and colon cancer, from an increase in oxidative DNA damage to effects on cell proliferation, free estrogen levels to hormonal catabolism. In contrast, fish oil-derived omega-3 fatty acids seem to prevent cancer by influencing the activity of enzymes and proteins related to intracellular signalling and, ultimately, cell proliferation. In this commentary, current evidence from experimental and human studies is summarized that implicates a high intake of omega-6 PUFAs in cancer of the breast, colon and, possibly, prostate and which indicates that omega-3 PUFAs and monounsaturated fatty acids such as oleic acid (omega-9) are protective. Plausible mechanisms for modulation of steps in the multistage carcinogenesis process by fats are discussed. Properly designed…

How strong is the evidence?

Evidence Hub reads this as a case-control, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free