Are you sure?

How many of you attempt to eat ‘healthily’ by replacing  of dietary saturated fats (from animal fats, common margarines, and shortenings) with omega 6 linoleic acid (from sunlower,  safflower and canola oils, polyunsaturated margarine)?

You may be interested in this report on the the Sydney Diet Heart Study, a single blinded, parallel group, randomised controlled trial conducted in 1966-73, in BMJ 2013;346:e8707 doi: 10.1136/bmj.e8707 (Published 5 February 2013).  And you may get a nasty surprise.

(Italics are mine, not the original authors.)


The intervention group (n=221) had higher rates of death than controls (n=237) (all cause 17.6% v 11.8%, hazard ratio 1.62 (95% confidence interval 1.00 to 2.64), P=0.05; cardiovascular disease 17.2% v 11.0%, 1.70 (1.03 to 2.80), P=0.04; coronary heart disease 16.3% v 10.1%, 1.74 (1.04 to 2.92), P=0.04). Inclusion of these recovered data in an updated meta-analysis of linoleic acid intervention trials showed non-significant trends toward increased risks of death from coronary heart disease (hazard ratio 1.33 (0.99 to 1.79); P=0.06) and cardiovascular disease (1.27 (0.98 to 1.65); P=0.07).


Advice to substitute polyunsaturated fats for saturated fats is a key component of worldwide dietary guidelines for coronary heart disease risk reduction. However, clinical benefits of the most abundant polyunsaturated fatty acid, omega 6 linoleic acid, have not been established. In this cohort, substituting dietary linoleic acid in place of saturated fats increased the rates of death from all causes, coronary heart disease, and cardiovascular disease. An updated meta-analysis of linoleic acid intervention trials showed no evidence of cardiovascular benefit. These findings could have important implications for worldwide  dietary advice to substitute omega 6 linoleic acid, or polyunsaturated fats in general, for saturated fats.”

So butter, and cream, and natural fats are not the big nasty horrors we have long been preached about.  You do not have to cut them entirely from your diet.  Of course, all fats should be eaten in moderation, and their calorific values should be considered a smaller part of your total intake.  But the seed oils, sunflower, safflower, canola etc are, due to their extraction methods, NOT beneficial to your health.  The best oil is cold pressed olive oil, which I use as my cooking oil, along with butter – sometimes together and sometimes one or the other.

Break out the butter and bon appetit!