As far as diet myths go, this is one of the WORST of all time.
I say this because as you'll learn, it caused a LOT of harm.
The myth of saturated fat being bad for our heart health actually increased deaths; this is the reailty and power of myths genereated from poor science.
THE TRUTH ABOUT SATURATED FAT
In 2014, another meta-analysis was released declaring that reducing saturated fat isn't the way forward for our heart health (1).
Whilst there had been others before hand, finally the media made a big deal out of it.
The authors concluded:
"Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats."
But unfortunetly this will take years to get through to people - only recently were people commenting on a picture posted on the FIT'N'FLEXED facebook page how bad saturated fats are.
It's engraved in the thoughts of many who lived through this period and it's very hard to get through to people with the truth, when they think they already have it.
WHERE THE MYTH BEGAN
Many blame the Seven Countries Study from 1970 that looked at saturated fat consumption and heart disease among over 12,700 men (2).
All it revealed was a simple link between the two - no cause and effect.
Smoking rates weren't taken into consideration and nor was exercise frequency.
But it gets worse; they left out the data from more than 10 nations and didn't elaborate on the findings that some countries had a high intake of saturated fat, and hardly any cases of heart disease!
But the consequences were severe; everyone was convinced that saturated fat was bad.
Thankfully, the media made this a big story in 2014, but even back in 2010 researchers from another meta-analysis (3) into saturated fat and heart diseases concluded:
“There is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of coronary heart disease or cardiovascular disease.”
And to say there's been a few more studies finding the same thing is an understatement (4,5,6,7,8,9,10).
BUTTER v MARGARINE - THE OTHER HEALTH DEBATE
In the wake of the 1970 Seven Countries study, margarine was touted as the healthier alternative to butter.
This was because had painted saturated fats as the villian, so margarine was favoured because of its polyunsaturated fats - specifically omega-6 fatty acids (eg corn oil which is in margarine).
Well didn't this cause problems.
A meta-analysis in 2010 reviewed the evidence into polyunsaturated fats and their link to cardiovascular disease (11).
The research aimed to look at the reactions of the two main forms of polyunsaturated fat: omega-3 and omega-6 (Margarine is very high in omega-6 fatty acids and butter is very low).
The researchers found that a larger intake of omega-6 didn't provide any positive health effects but both omega-6 and omega-3 fatty acids together do.
But here was the big finding:
“Advice to specifically increase intake (of omega-6 polyunsaturated fat)…is unlikely to provide the intended benefits, and may actually increase the risks of (coronary heart disease) and death.”
So the fats they they thought would assist in PREVENTING heart disease, did the opposite.
Then in 2013 researchers went over old papers including the Sydney Diet Heart Study, done between 1966 and 1973 (12).
It looked at 458 men from 30–59, all who had suffered a recent coronary event.
And their finding?
“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.”
Talk about a stuff up.
What was also found was those eating the recommended diet for heart health had their chance of dying from heart diease increased by 74%, and cardiovascular disease by 70%.
This is the power that nutrition myths have; the ability to put us in an early grave.
THE MEDITERRANEAN DIET FOR HEART HEALTH
These findings are echoed elsewhere.
Take for example, the Mediterranean diet. It has limited saturated fat but is low in omega-6 polyunsaturated acids.
It seems we want to limit omega-6 fatty acids at this stage, judging on the literature presented.
A study (13) printed in the April 2013 New England Journal of Medicine found that a Mediterranean diet:
“Substantially reduces the chance of a cardiovascular event, or stroke, amongst those at high risk”.
The Mediterranean diet features lots of monounsaturated fat sources: nuts, avocado, olive oil, etc whilst being quite low in omega-6 fatty acids.
So what do we take away from this?
That saturated fat is fine and butter is a healthier alternative to margarine.
Omega-6 fatty acids are not to be avoided but should be limited; and not chosen over saturated fats for better heart health.
There's no question that at this stage, the scientific data points to saturated fat being off the hook as a type of fat to cause heart disease and early death.
So rip into it, and don't be scared!
"Stay Fit, Stay Flexed!"
REFERENCES
(1) Chowdhury R et al. Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis. Ann Intern Med. 2014 Mar 18;160(6):398-406. doi: 10.7326/M13-1788.
(2) Keys A. Coronary heart disease in seven countries. Nutrition, 1970.
(3) Siri-Tarino PW, Sun Q, Hu FB, KRAUSS RM. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr. 2010 Mar;91(3):535-46.
(4) Saturated fat and cardiovascular disease: the discrepncy between the scientific literature and dietary advice. Hoenselaar, R. Department of Nutrition and Dietetics, High School of Arnhem and Nijmegen, The Netherlands. Nutrition. 2012 Feb;28(2):118-23.
(5) The questionable role of saturated and polunsaturated fatty acids in cardiovascular disease. The Ravnskov U. Journal of Clinical Epidemiology, 1998 Jun;51(6):443-60.
(6) Dietary polyunsaturated fatty acids and composistion of human aortic plaques. Felton CV, Crook D, et al. The Lancet, 1994 Oct 29;344(8931):1195-6.
(7) Saturated fat prevents coronary artery disease? An American paradox. Knopp RH, Retzlaff BM. American Journal of Clinical Nutrition, 2004 Nov;80(5):1102-3.
(8) Dietary fats and health: dietary recommendations in the context of scientific evidence. Lawrence GD. Advances in Nutrition, 2013 May 1;4(3):294-302.
(9) Dietary saturated fat intake, is there really an association with coronary heart disease? Rehman MS, Student RI. Journal of Pakistan Medical Association, 2012 Apr;62(4):411.
(10) Saturated fat, carbohydrates and cardiovascular disease. Kuipers RS, de Graaf DJ, et al. The Netherlands Journal of Medicine, 2011 Sep;69(9):372-8.
(11) Ramsden CE, et al. n-6 fatty acid-specific and mixed polyunsaturate dietary interventions have different effects on CHD risk: a meta-analysis of randomised controlled trials. Br J Nutr 2010;104:1586-600
(12) Ramsden CE, 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
(13) Struch R, M.D et al. Primary Prevention of Cardiovascular Disease with a Mediterranean Diet. N Engl J Med 2013; 368:1279-1. April 4, 2013.DOI: 10.1056/NEJMoa1200303.
Author
Dayne Hudson