Replacing saturated fat with Omega-6 Polyunsaturated fatty acids
may be harmful to your heart.
In the Sydney Diet Heart Study [1], published in BMJ (2013), selectively increasing the n-6 Poly Unsaturated Fatty Acid (Linoleic Acid) from safflower oil and safflower polyunsaturated margarine increased rates of death from cardiovascular disease (P=0.04), coronary heart disease (P=0.04), and all cause (P=0.05) mortality compared with a control diet rich in Saturated Fatty Acid from animal fats and common margarines.
These unfavorable effects of n-6 PUFA are consistent with two other randomized controlled trials [2] [3], in which experimental dietary conditions selectively increased n-6 PUFA in place of saturated fats by replacing animal fats and common margarines with corn oil.
Therefore, benefits previously attributed to greater intake of total PUFA might be specifically attributable to n-3 PUFAs, and are not necessarily generalizable to n-6 PUFA, or PUFAs in general.
References:
[1] Ramsden CE, Zamora D, Leelarthaepin B, et al.: Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. BMJ 2013;346:e8707.
[2] Rose GA, Thomson WB, Williams RT. Corn oil in treatment of ischaemic heart disease. BMJ 1965;1:1531-3.
[3] Frantz ID Jr, Dawson EA, Ashman PL, Gatewood LC, Bartsch GE, Kuba K, et al. Test of effect of lipid lowering by diet on cardiovascular risk. The Minnesota Coronary Survey. Arteriosclerosis 1989;9:129-35.
These unfavorable effects of n-6 PUFA are consistent with two other randomized controlled trials [2] [3], in which experimental dietary conditions selectively increased n-6 PUFA in place of saturated fats by replacing animal fats and common margarines with corn oil.
Therefore, benefits previously attributed to greater intake of total PUFA might be specifically attributable to n-3 PUFAs, and are not necessarily generalizable to n-6 PUFA, or PUFAs in general.
References:
[1] Ramsden CE, Zamora D, Leelarthaepin B, et al.: Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. BMJ 2013;346:e8707.
[2] Rose GA, Thomson WB, Williams RT. Corn oil in treatment of ischaemic heart disease. BMJ 1965;1:1531-3.
[3] Frantz ID Jr, Dawson EA, Ashman PL, Gatewood LC, Bartsch GE, Kuba K, et al. Test of effect of lipid lowering by diet on cardiovascular risk. The Minnesota Coronary Survey. Arteriosclerosis 1989;9:129-35.