Scientific Nutrition Update 48: Saturated Fats

 

I have written about saturated fats before but there are still many dietary recommendation agencies that are obsessed with them and I cannot figure out why.

Script (Remember I ad-lib):

For today’s episode I am going to talk about saturated fats.  That’s right, the most commonly villainized dietary fatty acids, saturated fats.  They are often claimed to be linked to heart disease, death, strokes, and a whole bunch of other nasty stuff.  But like always I have to look into what the science actually claims and it is more interesting than we think.

 

Now what is a saturated fatty acid? Well all that means is that there are no carbon to carbon double bonds and because of that it is saturated with hydrogens bonded to it.  This is in contrast to unsaturated fats that have double bonds and therefore are lacking some of the hydrogens. Unsaturated fats are further broken down into mono-unsaturated fats and poly-unsaturated fats, depending on whether there is a single double bond or multiple.  

 

This is where things get interesting, because it does not really seem that saturated fat is as evil as people claim.  First of all much of the hatred of saturated fats came from interpretations of the infamous Seven Countries Study by Dr. Keys.  In this study he plotted seven countries mortality vs fat consumption and saw that an increase in fat consumption was correlated with mortality, especially saturated fats.  However, there are several flaws with this study, one he has been accused of cherry picking his data, and others who have analyzed his data found out that both sugar and exercise were way better predictors of mortality.

 

There was an interesting analysis done in India that suggested if you ignore extreme values of saturated fat consumption then there was no correlation between saturated fat consumption and mortality and furthermore income was a much better predictor of mortality than saturated fat consumption.

 

Furthermore, in a meta-analysis looking at a wide variety of other studies it was found that the link between saturated fat and heart disease was tenuous at best and further concludes that recommending removal of saturated fats without suggesting compounds for caloric replacement you can end up with worse results.  For example if foods high in saturated fats are replaced with foods high in sugar mortality is likely to actually go up.

 

I am not saying that saturated fats are healthy, I am saying that they probably aren’t super unhealthy and the more time dietary recommendations waste their time worrying about them, the less time can be spent on factors that have significant gains.  Obsessing over saturated fats is a waste of time. So just do not do it. If you learned something today please consider sharing it with a friend, and thank you for tuning in.

Bibliography (I may not directly address these studies in the episode but I looked at them and thought they might be valuable):

 

American Dietetic Association. “Position of the American Dietetic Association and Dietitians of Canada: Dietary Fatty Acids.” Journal of the American Dietetic Association 107.12 (2007): 1599-1611. Web.

Keys, A, et al. “The Diet and 15-Year Death Rate in the Seven Countries Study.” American Journal of Epidemiology 124.6 (1986): 903-915. Web. 19 May 2015.

Mani, Indu and Anura Kurpad. “De-Mystifying Saturated Fats – A Perspective.” Indian Journal of Community Health (2014): 31-36. Web. 9 4 2015.

Mozaffarian, Dariush, Renata Micha and Sarah Wallace. “Effects on Coronary Heart Disease of Increasing Polyunsaturated Fat in Place of Saturated Fat: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” PLoS Medicine 7.3 (2010): 1-10. Web. 9 4 2015.

Willett, Walter and Patrick Skerrett. Suprising News About Fat. New York: Free Press-Simon Schuster, 2001. Print.

Find this podcast on:

Apple Podcasts

Google Play Music

Overcast

Pocket Casts

Anchor

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.