We have always heard and even been taught that saturated fat leads to cholesterol, and that cholesterol leads to heart disease but is this really true?
This all started in the 1950´s when a doctor by the name of Ancel Keys did a study in which he compared the rate of Heart Disease and Fat consumption in 6 countries: USA, Canada, Australia, England-Wales, Italy and Japan, and found a perfect correlation, meaning the more fat the countries ate, the higher the risk of heart disease. Except, there was one problem, he withheld data from other 16 countries. Later, when scientists plotted all 22 countries, the correlation wasn´t so perfect. In other words, he used only the data that would demonstrate his hypothesis, but you could show just the opposite with all the data, that the more saturated fat people ate, the less heart disease they had.
In between 1960-1975, there were probably a half a dozen of studies that failed to confirm that saturated fat was the cause of heart problems(1), but Ancel Key was in the American Heart Association and his idea prevailed. So, from then on, the number one enemy was saturated fat and cholesterol. The funny thing with this is that most people don´t even know what cholesterol is, they just think it is a bad thing but is it really?
Cholesterol is actually essential for life. It is a mayor component of brain and nerve tissue, and central for the production of hormones. In fact, it is so important that almost every single cell in the body makes it!!! 80 % to 90 % of your cholesterol is made by your body, and it is basically genetic, meaning most people are always going to stay in a range. So even if you cut all the cholesterol out of your diet, your body will simply start making a bit more to bring it backup into ¨its range¨ (2). But we have always heard that cholesterol is produced by saturated fats, although the literature regarding this is highly inconsistent and there are even many long-term studies that disagree with this idea (3,4,5). One study in particular is the one going on in Framingham Massachusetts, where they are studying the potential causes of heart disease(6). This study started in 1948 and is still going on!! And so far, they have seen that certain habits like cigarette smoking or emotional stress do lead in the direction of heart disease. Also, cholesterol correlates with heart disease but only until the late 40´s. In fact, after the age of 47 high cholesterol seems to be protective, meaning that the people who had the highest cholesterol lived the longest……. so could cholesterol actually be a good thing? And, if saturated fats and cholesterol aren´t a ¨bad thing¨ then what´s behind the epidemic of cardio-vascular diseases?? That and more in my next ¨blog¨ ;).
- Mann G. DIet-Heart end of an era. NEJM 1977 297;644-50.
- Curtis N E. The Cholesterol Delusion
- 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.
- Stamler J, Neaton D J. The Multiple Risk Factor Intervention Trial (MRFIT)- Importance Then and Now. JAMA.2008:300(11);1343-45.
- Mann V G. Coronary Heart Disease Doing the Wrong Thing. Nutrition today 1984 http://www.abc.net.au/catalyst/heartofthematter/download/GeorgeMann-CHDDoing_the_Wrong_Things.pdf
- Kannel WB. RIsk stratification in hypertension: new insights from the Framingham Study. Am J Ypertens, 2000 Jan;13(1 Pt2):3S-10S.
- Is saturated fat and cholesterol really that bad part 2? (sports-diet-pain.com)
- Everyone Was Wrong: Saturated Fat Is Good For You (greatist.com)
- Good news for saturated fat! (abieleanor.wordpress.com)
- ‘Saturated Fat No Link With Cholesterol Heart Attack (ramanan50.wordpress.com)
- WakingTimes – Dr. Malcolm Knedrick – The Great Cholesterol Myth – 23 November 2013 (lucas2012infos.wordpress.com)
- Time to end the war against saturated fat? (latimes.com)