22. The Skinny on Fats

Fat: The Good, The Bad, and The Ugly Truth

(or...more than you want to know, but everything you need to know)

(or..."How to Kick Your Fried Food Addiction)

(or..."Come with me if you want to Live!")

          The word “fat” is a generic term referring to hydrophobic chemical compounds that break down into fatty acids and glycerol. The word “lipid” is often used synonymously with “fat”; however, “lipid” refers more specifically to biochemical molecules. Dr. William Christie of the American Oil Chemists Society defines lipids as“… fatty acids and their derivatives, and substances related biosynthetically or functionally to these compounds,” (Harwood, 2012). This definition is probably the most accurate for our purposes in studying nutrition because the chemical relationship between the fatty acids and their glycerols or hydrocarbons in addition to how the body reacts to these chemicals is what makes a lipid “good” or “bad”. Triglycerides, or more appropriately (according to Dr. Christie), triacylglycerols, are the form lipids usually take; this is the molecule formed by three fatty acids (which may or may not be the same type of fatty acids) attached to a glycerol (Whitney, 2011). Triglycerides are essential to human functioning; what makes them good fats or bad fats depends on the quality and quantity consumed.

            “Good fats” and “bad fats” are relative terms that instead should be thought of as lipids that have a positive effect on health or lipids that have a less healthful effect. Most of us have been conditioned to avoid “fats” because we’ve been taught that consuming them will make us obese and put us at risk for heart disease; a nation obsessed with “lowering triglycerides” only resulted in an increase in obesity and diabetes (Cheung, 2012). The truth is, the body does need lipids (Balch, 2000). According to the American Heart Association, lipids are indispensable to body functions. They are an important energy source, support cell growth, protect and cushion the body, provide warmth, aid in nutrient absorption, and even secrete hormones (Fats 101, 2010). However, there are several different types of lipids with a variety of chemical and physical properties; it’s the type of lipid in the diet that makes all the difference.  

            Lipids are so important to life that even “fat-free” foods like vegetables contain trace amounts (Cheung, 2013). If all lipids have the same amount of calories, what is the difference between a beneficial lipid or an unhealthy lipid? The answer is in the chemical structure of the lipid itself. We already established that lipids are carbon and hydrogen molecules. Columbia University’s health-advocacy program, “Go Ask Alice,” explains saturation as “…whether all the available spaces on the carbon chain are bonded to hydrogen atoms, or if there are any hydrogen atoms missing,” (McNeil, 2012). This chemical structure relates to how the body deals with cholesterol. There are four categories of lipids: Saturated, Monounsaturated, Polyunsaturated, and Trans-Fats (USDA, 2010). The degree to which a lipid is “saturated” is directly related to the degree of viscosity at room temperature (Whitney, 2011). In chemical terms, this means that longer carbon chains make “firmer” lipids. 

            Before we discuss these lipids and how they are classified as “good” or “bad”, we have to pause a moment and discuss cholesterol. Neither fat nor cholesterol are water-soluble, yet our blood (and the body in general) is mostly made up of water (Good Vs. Bad Cholesterol, 2012). Until the body can break down the lipids and esters for use, they have to be transported around the body, so they get bundled into lipoproteins that can flow in the vascular system. Small and dense lipoprotein packages are referred to as high-density lipoproteins (HDLs), while large and less-dense packages are called low-density lipoproteins (LDLs) (Cheung, 2013). LDLs transport cholesterol from the liver to the body, whereas HDLs transport unused cholesterol from the body back to the liver for elimination. When there is too much LDL in the body, it tends to stick and form plaque, which can narrow arteries and inhibit blood flow. Accumulated LDL leads to atherosclerosis, a form of arteriosclerosis, which is a cause of hypertension and heart disease (Marieb, 2007). HDLs have been referred to as the “garbage trucks” of the vascular system because of their ability to remove cholesterol from vessel walls and take it back to the liver. Now, let’s look at lipids again. 

            Saturated Fats (SFs) are called as such because all of the available carbon atoms have reached their capacity to attach to hydrogen atoms (Haas, 1992). These lipids are found in animal products like meat, cheese, and dairy, as well as the “tropical” oils, coconut and palm oil (Kennedy, 2013). Consumption of these should be limited to 20g a day; eating more than that leads to negative health effects. These lipids are solid at room temperature and are the most stable, but their presence results in elevated LDLs. 

            Monounsaturated Fats (MUFAs) have a double bond between two carbon atoms because they are missing a hydrogen atom. MUFAs are vegetable oils; the plant keeps its most concentrated energy source in its seeds to promote the growth of its offspring (Biofuels Quick Guide). Therefore, MUFAs, which are HDLs, can be found in nuts and seeds such as olive, canola, sunflower, safflower, peanut, hemp, and soy (Kennedy, 2013). It is easy to see how vegetarians have a significantly lower rate of heart disease and cancer because of their high intake of HDLs and extremely low intake of LDLs, and in fact studies have shown this exactly (Huang, 2012). We can extract and consume MUFAs from plants, which exist in a liquid state at room temperature. 

            Polyunsaturated Fats (PUFAs) are missing more than one hydrogen atoms; consequently; they have multiple double carbon bonds. Omega-3s (linolenic acid), Omega-6s (linoleic acid), and Omega-9s (oleic acid and others) are all PUFAs that express this double bond in the third, sixth, or ninth space from the end of the carbon chain; the lower the number, the less stable and more delicate the oil. Omega oils are especially beneficial because they can help in reducing inflammation (Lee, 2012), lower triglycerols, and aid in preventing heart attacks (McNeil, 2012). Omega-3s and omega-6s are referred to as “essential fatty acids,” or EFAs. Dr. Andrew Weil succinctly explained EFAs when he said, “The body needs omega-3 and omega-6 fatty acids but can't make them, which is why they're termed ‘essential’," (Weil, 2012). Other omega fats are not “essential” because our bodies can make them from what we eat, if we eat the right balance of foods. The omega-3s eicosapentaenoic acid (EPA) and docosahexaenoic (DHA) are vital for the body to manufacture certain hormones. If one fails to consume enough omega-3s, the body will experience a deleterious effect on the immune system, the ability to clot (blood), and the ability to grow cells and maintain cell membranes (Weil, 2012). Omega-6s proliferate in American diets, as they are found in seeds, nuts, and grain-fed meats. The concern with omega-6s is not in getting enough, but in overconsumption. Omega-3s and -6s seem to be antagonistic in a synergistic way – they perform opposite functions but both must be present for body systems to work properly; balance is the key. PUFAs are most commonly found in fish such as salmon, halibut, mackerel, tuna, sardines, herring, and lake trout, but they are also found in olive oil, flax seeds and walnuts (Kennedy, 2013). PUFAs also form HDLs that exist in a liquid state at room temperature. 

            Trans-Fats (TFs) are totally unnatural, which is why they are some of the most unhealthy lipids. Chemists form TFs by breaking the carbon bonds of PUFAs and forcing hydrogen atoms to bind, thus deriving the term “hydrogenated.” Dr. Elson Haas describes a characteristic of MUFAs and PUFAs: “Unsaturated fats are unstable at room temperature and sensitive to interaction with oxygen, light, and heat,” (Haas, 1992). This means they spoil easily, and manufacturers of processed foods solved the problem with hydrogenation. This process involves the use of heat, which destroys fatty acids and the positive characteristics of PUFA (Balch, 2000), but the result is a product with a longer carbon chain and a longer shelf-life. It enables manufacturers to makes the lipid into a solid at room temperature, but it turns a perfectly good PUFA into essentially a SF. Hydrogenated oils are found in commercially prepared foods, such as margarine and shortening, and are often used as fry oil in fast food restaurants (Kennedy, 2013). The main reason that TFs are so unhealthy is because they increase LDLs and actually decrease HDLs (McNeil, 2013). Here’s a tip: don’t eat anything that’s described in terms of “shelf-life;” nutritious and healthy food wasn’t meant to sit around, it’s meant to be eaten fresh. Avoiding processed foods, fried foods, and commercially-prepared foods is a great way to ensure TFs stay out of your body. 

After examining lipids, it seems clear that, as Dr. Joel Furhman says, “[Nutritious food] in the diet [has] dramatic effects at reducing the risk of both heart disease and most cancers…(and) animal products increase…the risk of both heart disease and cancer,” (Furhman, 2004). The good news is that in many ways, the vegetarians got it right, because the most beneficial fats are found in plants. The bad news is that many foods we over-consume due to tastes and habits, such as meats and dairy, contain lipids that are desirable only in small quantities. The ugly truth is that artificially created anything should not be consumed at all, and the only way to manage a healthy diet is to eat the right balance of natural fats. The beautiful truth is that the body has an amazing capacity to heal, and it’s never too late to make changes that encourage it to do so. Researching this topic has completely eliminated any desire I have to eat hydrogenated oils, and it illuminated the necessity for balance in lipid consumption, both with regard to quantity and constitution.    

 

Watch this video to see exactly how fats can kill you.

        

  There is hope for you, though. Stop eating as much bad fats and read the Wikipedia section on Atherosclerosis/Diet and Dietary Supplements here: Atherosclerosis. It's a good starting point. Exercise. Eat plants. Drink water. Be happy :)

Bibliography

 

Balch, CNC, Phyllis A., and James F. Balch, MD. Prescription for Nutritional Healing.3rd ed. New York, NY: Penguin Putnam, 2000. Print. Pg 68.
 

"Biofuels Quick Guide." Optimus Technologies. Penn State University, n.d. Web. 24 Jan. 2013. http://optimustec.com/Documents/Biofuels%20Quick%20Guide.pdf.

 

Cheung, D.Sc., Lilian, ed. "Fats and Cholesterol: Out with the Bad, In with the Good."  The Nutrition Source. Harvard University School of Public Health, Jan. 2012. Web. 23 Jan. 2013. http://www.hsph.harvard.edu/nutritionsource/fats-full-story/.

"Fats 101." Getting Healthy. American Heart Association, 5 Aug. 2010. Web. 24 Jan.             2013.http://www.heart.org/HEARTORG/GettingHealthy/FatsAndOils/Fats101/Fats-101_UCM_304494_Article.jsp.

Fuhrman, MD, Joel. "What You Need to Know About Vegetarian or Vegan Diets." Dr.             Fuhrman: How to Live for Life. Dr. Joel Fuhrman Library, 2004. Web. 24 Jan.2013. .

"Good vs Bad Cholesterol." Conditions. American Heart Association, 5 Sept. 2012. Web.   24 Jan.2013.  http://www.heart.org/HEARTORG/Conditions/Cholesterol/AboutCholesterol/Good-vs-Bad-Cholesterol_UCM_305561_Article.jsp .

Haas, MD, Elson M. Staying Healthy with Nutrition. Berkely, CA: Celestial Arts, 1992.   Print. Pgs. 65-71.

Harwood, PhD, John L., Randall J. Weselake, PhD, and William Walker Christie, MBE, PhD, eds. "A Lipid Primer; Oils and Fats." The AOCS Lipid Library. American  Oil Chemist's Society, 15 Aug. 2012. Web. 24 Jan. 2013.   .

Huang, T., et al. "Cardiovascular disease mortality and cancer incidence in vegetarians: a meta-analysis and systematic review." PubMed.gov. National Institute of Health,1 June 2012. Web. 24 Jan. 2013.  .

Kennedy, MD, Martha Nolte, et al. "Good Fats, Bad Fats." Diabetes Education Online.             University of California, San Francisco, 1 Jan. 2013. Web. 24 Jan. 2013.             .

Lee, H. N., and Y. J. Surh. "Therapeutic potential of resolvins in the prevention and treatment of inflammatory disorders." PubMed.gov. National Institute of health, 15 Nov. 2012. Web. 24 Jan. 2013. .

Marieb, E. N., RN, PhD, & Hoehn, K., MD, PhD. (2007). Chapter 19: the Cardiovascular           System. In Human Anatomy and Physiology (9th ed., pp. 700-701). Glenview, IL:Pearson.

McNeil, CHES, EdD, Michael P., ed. "Good Fats Vs. Bad Fats." Go Ask Alice. Columbia University, 9 Aug. 2012. Web. 24 Jan. 2013. http://goaskalice.columbia.edu/good-vs-bad-fats

U.S. Department of Agriculture and U.S. Department of Health and Human Services. Dietary Guidelines for Americans. 7th ed. Washington, DC: U.S. Government  Printing Office, 2010. Print.

Weil, MD, Andrew. "Q & A Library: Need Omega 9 Fatty Acid?" Dr. Weil.com. Andrew           Weil, MD, 20 Dec. 2012. Web. 24 Jan. 2013.             http://www.drweil.com/drw/u/QAA401214/Need-Omega-9-Fatty-Acid.html.

Whitney, E. & Rolfes, S. (2011). Understanding Nutrition. 12^th Ed. Ch.5, p. 133-171. Belmont, CA: Wadsworth Cengage Learning