Can Saturated Fat Really Be Harmful?

David Katz, MD, Director, Yale Prevention Research Center, recently wrote an article (http://huff.to/lfsqjk) negatively critiquing the many new reports exonerating saturated fat from wrong doing. Dr. Katz said the question isn't, "Is saturated fat harmful?" but "Is all saturated fat created equal?"

(Fatty acids are chains of carbon (C-C-C-C) connected by chemical bonds. A saturated fat has chemically stable single bonds. Saturated fats are non-reactive because the single bonds are filled or saturated with hydrogen. Saturated means chemically stable, nothing else.)

Dr. Katz rightly points out that saturated fat is a class of compounds. As an example, there are eight different saturated fats in butter, each with a different chain length - ranging from 4 carbon (4C) butyric acid to 18 carbon (18C) stearic acid, the dominant fat in both beef and chocolate. 

Speaking well of HDL-raising stearic acid, Dr Katz goes on to say:  

 "I consider the evidence strong that palmitic and myristic acids, two of the commonly consumed saturated fats, are, indeed, potentially harmful, contributing to inflammation, elevated lipids, atherogenesis and vascular
 disease." 

He didn't cite any evidence, so let's take a closer look at saturated palmitic acid (16C). Dr. Mary G. Enig, lipid biochemist, would agree with Katz that the "saturated fatty acids are not all the same." Enig would add: Saturated fats come in different chain lengths and have a different purpose, role and metabolism within the body.  

According to Enig, palmitic acid (16C) "is the major fatty acid in normal lung surfactant." That's right, 68 percent of the fat protecting the lungs is palmitic acid. Palmitic acid is also called "the stem fatty because it is the de novo fatty acid made in the body from acetyl-CoA." Now if a healthy body synthesizes palmitic acid, can it be 'bad'?  

Butter, chicken (including the skin), cocoa butter, lard, and beef tallow all contain approximately 25 to 26 percent palmitic acid. Is it bad for babies - human milk fat ranges from 20 to 25 percent palmitic acid? At 45 percent, tropical palm oil is highest in palmitic acid - associated with longevity in traditional South Pacific and East African diets. Even 'good' olive oil is 14 percent palmitic! 

As you can see, animals, humans, plants and microorganisms share fatty acids. According to Dr. Enig, your body can't tell the difference between palmitic acid in chicken or palmitic acid in olive oil - it's the same. Lipid textbook author and biochemist Dr. Michael Gurr reminds us that: 

 "Palmitic is the most common saturated fatty acid in animals, plants, and microorganisms."

Did the Creator of the Universe make a mistake - we all got a bad deal - or is Dr. Katz, like most other medical professionals, afraid or reluctant to admit that the medical profession and so called health experts have been wrong about saturated fat for 50 years - since 1961!  

While 'the experts' embrace olive oil - the 'good' Queen Lipid in the "Mediterranean Diet" invented by Ancel Keys - you can't fool the body. According to Dr. Enig:

 "Humans and other animals make palmitic acid and stearic acid out of carbohydrates and protein, and these two saturated fats are changed into both 16 and 18 carbon monounsaturated fats to maintain desirable physiological balances." (Italics are mine.)

18 carbon monounsaturated fat is oleic acid, the dominant fat in olive oil - and the dominant fat in butter. Enig explains:  The palmitic acid that man eats can end up as oleic because the liver and other tissues can convert palmitic acid into oleic acid - as needed - to maintain "desirable physiological balances." 

All cell membranes contain fatty bi-layers - true homeland security. Overload on olive oil and your body will simply convert any excess monounsaturated fat into saturated palmitic or stearic acid. Remember, our 70 trillion cell membranes - especially lung surfactant - require 50 percent or more saturated fat for stability and optimum body functioning. 

Dr. Katz is picking on palmitic because - isolated in a laboratory study - palmitic acid can potentially elevate blood cholesterol levels:

 "First, we have innumerable studies showing that saturated fats -- notably palmitic and myristic acids which are found in dairy, meat and many processed foods -- can increase blood lipids and contribute to inflammation."

Now, Dr. Katz didn't site any of those "innumerable studies," but British lipid biochemist Michael Gurr does in his 1999 book, Lipids In Nutrition and Health: A Reappraisal - currently available as a free download at http://bit.ly/ln3bYG. Saying that "Dietary saturated fat-plasma-lipid interrelationships have been grossly oversimplified," Gurr wrote:  

 "The extent to which palmitic and myristic acids would raise cholesterol is dependent on the concentration of linoleic acid in the dietary mix and possibly interactions with other dietary components."

You never consume palmitic by itself because all food fats are combinations of fat - saturated and unsaturated. Butter contains 12 different fats, 8 different saturates, and is 30 percent unsaturated. Butter is actually dominantly oleic acid (28 percent), the dominant fat in olive oil and the most common fat in plants and animals. In the real world, natural fats are always combined together.  

Lipid biochemistry is much more complicated than the dummied-down misinformation handed down to us since 1961 when the American Heart Association first told us to replace our healthy traditional more monounsaturated and saturated fats with their highly touted, new-fangled polyunsaturated vegetable oils - trans fats and all. 

AHA board members in 1961 included Ancel Keys - "father of the low fat diet." His chief supporter on the board was Jeremiah Stamler, a professor from Northwestern. Stamler is the author of Your Heart Has Nine Lives, a book advocating the substitution of vegetables oils for butter and other so called "artery-clogging saturated fats." The book was paid for by the makers of Mazola Corn Oil and Mazola Margarine. 

A final bit of common sense. The French have a high saturated fat diet and low rates of heart disease (google MONICA study). The French are heavy smokers but have relatively low rates of lung cancer. Do you think that palmitic acid - a stem fatty acid that represents 68 percent of lung surfactant - is a protective food for the French? 

There is no French paradox - they simply eat the fats that George and Martha Washington enjoyed at Mount Vernon. The French can't win wars but they know what to eat: high quality butter, chicken (and the skin), pastured beef, and lard from outdoor-living pigs. They're not afraid to eat the crispy chicken skin we give to our dogs!  

Don't get me wrong, extra virgin olive oil is the best vegetable oil for medium-heat cooking. The reason olive oil is good is because it contains a lot of monounsaturated fat - oleic acid - which is easily converted in the body into saturated fat. Saturated fat, in turn, and there are many varieties, is best for frying and high temperature cooking. The best cooking fats contain a combination of 'good' monounsaturated fat and 'good' saturated fat - including palmitic acid.

 

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