Omega-6 vs. Omega-3: Linoleic Acid Promotes Cancer Development
Omega 6: Abundant Linoleic Acid Promotes Tumor Development
A diet rich in linoleic acid, a well-known Omega-6 fatty acid, can promote tumor growth. This was demonstrated in a study published in the British Journal of Cancer, based on research from experts at the Laboratory of Molecular Carcinogenesis, National Institutes of Health (Research Triangle Park, USA), and Osaka City University Graduate School of Medicine (Osaka, Japan). The results showed that linoleic acid favors cancer proliferation by promoting the formation of new blood vessels within the tumor mass, which supply the tumor with the nutrients necessary for its growth. These findings highlight that Omega-6 fatty acids act oppositely to Omega 3 fatty acids, which have been shown in multiple studies to counter tumor growth.
A Matter of Balance
Dietary intake of fatty acids is closely linked to the risk of developing various cancers. Scientists have long emphasized the importance of the balance between Omega-6 and Omega-3 fatty acids in cancer prevention. Research indicates that the lower the Omega-6 to Omega-3 ratio, the lower the cancer risk. However, Western diets are increasingly rich in Omega-6, with linoleic acid (LA) being the most abundant.
Omega-6 and Stomach Cancer
The British Journal of Cancer study focused on the role of linoleic acid in the development of stomach cancer. Researchers used two model systems: gastric carcinoma cells grown in vitro and animal models. By comparing gene expression between linoleic acid-treated and untreated carcinoma cells, they identified genes potentially activated by Omega-6. These genes regulate processes critical to cancer development: angiogenesis (formation of new blood vessels), apoptosis (programmed cell death), cell invasion, degradation of the extracellular matrix, and cell survival. The study showed linoleic acid activates the expression of plasminogen activator inhibitor 1 (PAI-1), which enhances the invasive ability of tumor cells. Furthermore, PAI-1 activation suppresses angiostatin, a protein that inhibits angiogenesis, thereby increasing blood vessel formation in tumors. Animal experiments confirmed that increased dietary linoleic acid promotes tumor growth.
Omega-6 and Omega-3: Opposing Roles in Cancer
Based on these findings, the authors concluded that unlike Omega-3, Omega-6—and specifically linoleic acid—can promote critical processes involved in tumor invasion and angiogenesis. They suggest that reducing dietary linoleic acid intake could help slow disease progression.
Sources
1. Nishioka N, Matsuoka T, Yashiro M, Hirakawa K, Olden K, Roberts JD, “Linoleic acid enhances angiogenesis through suppression of angiostatin induced by plasminogen activator inhibitor 1”, Br J Cancer. 2011 Nov 22;105(11):1750-8
2. Anti M, Marra G, Armelao F, Bartoli GM, Ficarelli R, Percesepe A, De Vitis I, Maria G, Sofo L, Rapaccini GL, et al, “Effect of omega-3 fatty acids on rectal mucosal cell proliferation in subjects at risk for colon cancer”, Gastroenterology. 1992 Sep;103(3):883-91.
3. Huang YC, Jessup JM, Forse RA, Flickner S, Pleskow D, Anastopoulos HT, Ritter V, Blackburn GL, “n-3 fatty acids decrease colonic epithelial cell proliferation in high-risk bowel mucosa”, Lipids. 1996 Mar;31 Suppl:S313-7
4. Sasaki S, Horacsek M, Kesteloot H, “An ecological study of the relationship between dietary fat intake and breast cancer mortality”, Prev Med. 1993 Mar;22(2):187-202
5. Simonsen NR, Fernandez-Crehuet Navajas J, Martin-Moreno JM, Strain JJ, Huttunen JK, Martin BC, Thamm M, Kardinaal AF, van't Veer P, Kok FJ, Kohlmeier L, “Tissue stores of individual monounsaturated fatty acids and breast cancer: the EURAMIC study. European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Breast Cancer”, Am J Clin Nutr. 1998 Jul;68(1):134-41.
