A Possible Mechanism by Which Dietary Fat Can Alter Tumorigenesis: Lipid Modulation of Macrophage Function
Numerous expiremental and epidemiological studies hace provided evidence linking dietary fat with increased risk for breast cancer. Some epidemiological studies have reported a positive correlation between breast cancer and dietary fat intake1 while a few have reported that no correlation existed.2–5 In contrast, studies with animal models of mammary tumorigenesis are more consistent. In general, the studies in rodents showed that high levels of dietary fat to an increased incidence of spontaneous or carcinogen-induced breast tumors as compared to animals fed a moderate or low level of dietary fat.6 In addition, rodents fed saturated fats.7–8 Not only has dietary fat been linked to altered primary tumor growth, but it also appears to influence the process of metastasis.9 Since linoleic acid (18:2n-6) was the most abundant fatty acid found in many of the polyunsaturated vegetable oils numerous investigators hae suggested that it may be pivotal in the promotion of mammary tumorigenesis. The role of linoleic acid in increasing carcinogen-induced mammary tumor incidence10 as well as metastasis11 has been previously demonstrated.
KeywordsMacrophage Function Mammary Tumorigenesis Tumoricidal Activity Murine Peritoneal Macrophage Dietary Polyunsaturated Fatty Acid
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