Dietary long-chain n-3 fatty acids for the prevention of cancer: a review of potential mechanisms.
Increasing evidence from animal and in vitro studies indicates that n-3 fatty acids, especially the long-chain polyunsaturated fatty acids eicosapentaenoic acid and docosahexaenoic acid, present in fatty fish and fish oils inhibit carcinogenesis. The epidemiologic data on the association between fish consumption, as a surrogate marker for n-3 fatty acid intake, and cancer risk are, however, somewhat less consistent. This review highlights current knowledge of the potential mechanisms of the anticarcinogenic actions of n-3 fatty acids. Moreover, a possible explanation of why some epidemiologic studies failed to find an association between n-3 fatty acid intake and cancer risk is provided. Several molecular mechanisms whereby n-3 fatty acids may modify the carcinogenic process have been proposed. These include suppression of arachidonic acid-derived eicosanoid biosynthesis; influences on transcription factor activity, gene expression, and signal transduction pathways; alteration of estrogen metabolism; increased or decreased production of free radicals and reactive oxygen species; and mechanisms involving insulin sensitivity and membrane fluidity. Further studies are needed to evaluate and verify these mechanisms in humans to gain more understanding of the effects of n-3 fatty acid intake on cancer risk.
Larsson
Susanna C
SC
Division of Nutritional Epidemiology, The National Institute of Environmental Medicine, Karolinska Institutet, Stockholm. susanna.larsson@imm.ki.se
Kumlin
Maria
M
Ingelman-Sundberg
Magnus
M
Wolk
Alicja
A
D000818:Animals; D001943:Breast Neoplasms / Q000517:prevention & control*; D004032:Diet; D015777:Eicosanoids / Q000096:biosynthesis; D004812:Epidemiologic Methods; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000378:metabolism / Q000627:therapeutic use; D005260:Female; D005399:Fishes; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D008297:Male; D008460:Meat; D011471:Prostatic Neoplasms / Q000517:prevention & control*; D015398:Signal Transduction / Q000187:drug effects
D015777:Eicosanoids; D015525:Fatty Acids, Omega-3