Adipose Tissue Omega-3 and Omega-6 Fatty Acid Content and Breast Cancer in the EURAMIC Study

Abstract

The fatty acid content of adipose tissue in postmenopausal breast cancer cases and controls from five European countries in the European Community Multicenter Study on Antioxidants, Myocardial Infarction, and Cancer (EURAMIC) breast cancer study (1991 -1992) was used to explore the hypothesis that fatty acids of the omega-3 family inhibit breast cancer and that the degree of inhibition depends on background levels of omega-6 polyunsaturates. Considered in isolation, the level of omega-3 or omega-6 fat in adipose tissue displayed little consistent association with breast cancer across study centers. The ratio of long-chain omega-3 fatty acids to total omega-6 fat showed an inverse association with breast cancer in four of five centers. In Malaga, Spain, the odds ratio for the highest tertile relative to the lowest reached 0.32 (95% confidence interval 0.13-0.82). In this center, total omega-6 fatty acid was strongly associated with breast cancer. With all centers pooled, the odds ratio for long-chain omega-3 to total omega-6 reached 0.80 for the second tertile and 0.65 for the third tertile, a downward trend bordering on statistical significance (p for trend = 0.055). While not definitive, these results provide evidence for the hypothesis that the balance between omega-3 and omega-6 fat may play a role in breast cancer. Am J Epidemiol 1998;147:342-52. adipose tissue; breast neoplasms; fatty acids; fatty acids, omega-3Breast cancer rates vary greatly across industrialized nations. The incidence rate in the United States is nearly five times that of Japan. In the neighboring countries of Spain and France, annual female breast cancer incidences differ by 50 percent (86 and 129 per 100,000, respectively) (1). Despite clear associations of hormonal, reproductive, and genetic factors with breast cancer risk, most of the variation in occurrence across populations does not appear to be attributable to

Should animal fats be back on the table? A critical review of the human health effects of animal fat

“…The ratio of n-6 to n-3 PUFA (OMR) in animal fats may make an important contribution to human health although it is not clear whether these are all direct effects or whether they are partial effects due to food overconsumption and obesity. Several studies have shown that a high OMR in tissues or cholesteryl-esters is associated with several diseases including cancers such as prostate, bowel and breast cancer, CVD, autoimmune diseases and inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease (Godley et al 1996;Harvei et al 1997;Gogos et al 1998;Simonsen et al 1998;Yang et al 1999c;Simopoulos 2008;Murff et al 2011). Intake of many types of fat have been examined, with a suggestion of a threshold of n-6 PUFA, and reduced rates of disease for fats or oils low in n-6 PUFA, including animal fat (Zock and Katan 1998;Freedman et al 2008;Alexander et al 2010;Brennan et al 2010;Dong et al 2011;Gilsing et al 2011;Liu et al 2011;Psaltopoulou et al 2011;Chajes et al 2012).…”

No relations between breast cancer risk and fatty acids of erythrocyte membranes in postmenopausal women of the Malmö Diet Cancer cohort (Sweden)

“…A European multicentre study examining ratios of o3 to o6 fatty acids in adipose tissue in relation to breast cancer risk (Simonsen et al, 1998) found consistent inverse associations of the fatty acid ratios with breast cancer across most study centres (Kohlmeier, 1997). Two breast cancer studies that examined fatty acids in phospholipids (Chajès et al, 1999) and erythrocytes (Pala et al, 2001) suggest complex relations between diet, fatty acid and hormone metabolism, and breast cancer.…”

n-3 Polyunsaturated fatty acids throughout the cancer trajectory: influence on disease incidence, progression, response to therapy and cancer-associated cachexia

“…skewed n-6:n-3 PUFA ratio in maize oil may be supportive of tumour growth or altered immune functions (Black et al 1992;Rose & Connolly, 1993;Simonsen et al 1998;Klein et al 2000;Furukawa et al 2002;Calder, 2003). The balance of n-6 and n-3 PUFA rather than the total amount of fat consumed may be more important in determining cancer risk.…”