Dietary long-chain n-3 fatty acids for the prevention of cancer: a review of potential mechanisms

• Published in: The American journal of clinical nutrition 2004-06, Vol.79 (6), p.935-945
• Main Authors: Larsson, S.C, Kumlin, M, Ingelman-Sundberg, M, Wolk, A
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Breast Neoplasms - prevention & control; Cancer; Diet; Eicosanoids - biosynthesis; Epidemiologic Methods; Fatty acids; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - metabolism; Fatty Acids, Omega-3 - therapeutic use; Feeding. Feeding behavior; Female; Fish; Fishes; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Neoplastic - drug effects; Humans; Male; Meat; MEDICIN; Medicin och hälsovetenskap; MEDICINE; Oils & fats; Prevention; Prostatic Neoplasms - prevention & control; Risk factors; Signal Transduction - drug effects; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0002-9165; 1938-3207; 1938-3207
• DOI: 10.1093/ajcn/79.6.935

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.