The saturated fats have a reputation for being bad for you, but are they really that bad for you? What are the real negative aspects of saturated fats? And are these negative aspects true for all saturated fats? This article explores why we avoid saturated fats.
As seen in part 1 of this article series (What is saturated fat?), there are many different types of saturated fatty acids with varying chain lengths and as seen in part 2 of this article series (benefits of saturated fats), they each have slightly different benefits. It seems reasonable to reason that they each would also have varying negative side effects, and this is indeed what we find.
Negative aspects of the Short-chain saturated fatty acids
The shortest chain fatty acids are most acidic, with acetic acid (2:0) being the most acidic, which makes sense as it is the main fatty acid component of vinegar. The acidic nature of acetic acid in food when eaten in normal contexts is considered harmless. Having said that, it’s not advisable to glug undiluted vinegar down on its own as it can have acid-corrosive effects on tooth enamel, and may burn and irritate internal tissues and cells. Having it in moderation as part of a salad dressing, sauce, or diluted in water should be fine though.
To the best of my knowledge, there appear to be no negative effects from eating propionic (3:0), butyric (4:0) or caproic (6:0) acid in foods. There are only positive effects. (see link for the benefits of these saturated fats)
Negative aspects of the Medium-chain saturated fatty acids
Caprylic acid (8:0) doesn’t really have many negative side effects other than having a rancid taste which can sometimes cause nausea and gastrointestinal upset. Some people are more sensitive to caprylic acid than others. If used as an antimicrobial, the killing off of microbes can lead to what naturopaths call a “healing crisis” where the death of microbes can release chemicals into the body which can lead to headaches, nausea and other unpleasant symptoms. Working alongside a naturopath can help prepare your body before and after caprylic acid treatment to minimize negative side effects of the healing crisis. Another word of warning is that when using caprylic acid to fight gut microbes, people with a sensitive gut wall (e.g. people prone to inflammatory gut diseases like ulcerative colitis) may find that the killing off of microbes flares up inflammation. In such cases, caprylic acid should be used with caution, if at all. Aside from these effects there are no other known negative effects of caprylic acid.
There are no known negative effects of Capric acid (10:0) to health.
Lauric acid (12:0) has very few negative side effects. The only disadvantage of lauric acid is that as well as raising the “good cholesterol”, HDL, it also raises LDL cholesterol, the “bad cholesterol”. The LDL rise is small in comparison to other long-chain saturated fatty acids, and the rise is modulated by the equally significant rise of HDL, but it is an LDL rise nonetheless.1
Data Source: Katan et al. 1994. Effects of fats and fatty acids on blood lipids in humans: an overview, Am J Cli. Nutr.; 60(suppl): lOl7S -22S.
Also, like caprylic acid, the antimicrobial effects of lauric acid may result in a minor healing crisis if not used properly.
Negative aspects of the Long-chain saturated fatty acids
The long-chain saturated fats are those which have given saturated fats a bad name. Most of the long-chain saturated fats increase LDL cholesterol, increase risk of cardiovascular disease and atherosclerosis.
Myristic acid (14:0) raises LDL more than any other saturated fat, as can be seen in the graph above.2,3 Although it also raises HDL, the LDL rise is far greater, so the net effect on blood cholesterol is certainly a negative one that increases risk of cardiovascular disease.2,3
Other negative health effects of myristic acid are that several studies have found possible association between high myristic acid consumption and an elevation in risk of developing prostate cancer.4,5,6
Like myristic acid, palmitic acid (16:0) also raises LDL far more significantly than it raises HDL (see the graph above), and is therefore a risk factor for heart disease too.2,7
Palmitic acid has been associated with other negative impacts on health including increasing the risk of diabetes type 28, and it may play a role in suppressing our satiety control which tells us when to stop eating, which means it may play a role in contributing to weight gain.9
Worryingly, palmitic acid is the number 1 most abundant saturated fat in foods, which explains why the sweeping generalization that “saturated fats are bad for you” arose. Considering that palmitic acid is the dominant saturated fat in virtually all foods that contain saturated fats, it is fairly safe to say that few such foods that are rich in saturated fats are completely good for you although some may have some benefits as well as the simultaneous negative effects. (as discussed in benefits of saturated fats).
Perhaps surprisingly, stearic acid (18:0) does not raise LDL, unlike its close family members, palmitic and myristic acid. As seen in the graph above, it in fact lowers LDL rather than raises it! Like palmitic acid however, stearic acid intake has been correlated with types 2 diabetes risk.8
Longer chain fatty acids, longer than 18 carbons, like behenic acid (22:0) are not found in high amounts in food, but behenic acid has been found to increase LDL cholesterol.10
So what’s the conclusion? Is saturated fat bad for you overall?
Read on to read my Conclusion on Saturated Fats: Is saturated fat bad for you?
- Denke & Grundy 1992; Am J Clin Nutr November 1992 vol. 56 no. 5 895-898
- Katan et al 1994.Effects of fats and fatty acids on blood lipids in humans: an overview, Am J Cli. Nutr., 60(suppl):lOl7S-22S. (via http://www.scientificpsychic.com/fitness/fattyacids2.html)
- Mensink 1993.Am J Clin Nutr. 53(suppl):711S-714S
- Männistö et al. 2003. Fatty acids and risk of prostate cancer in a nested case-control study in male smokers. Cancer Epidemiology, Biomarkers & Prevention 12 (12): 1422–8.
- Crowe et al. 2008. Fatty acid composition of plasma phospholipids and risk of prostate cancer in a case-control analysis nested within the European Prospective Investigation into Cancer and Nutrition. The American Journal of Clinical Nutrition 88 (5): 1353–63.
- Kurahashi et al. 2008. Dairy product, saturated fatty acid, and calcium intake and prostate cancer in a prospective cohort of Japanese men. Cancer Epidemiology, Biomarkers & Prevention 17 (4): 930–7
- Simon. 1995. Serum fatty acids and the risk of coronary heart disease. American Journal of Epidemiology. 142(5):469-476.
- Wang et al. 2003. Plasma fatty acid composition and incidence of diabetes in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study. Am J Clin Nutr. 78(1):91-98.
- Benoit et al. 2009. Palmitic acid mediates hypothalamic insulin resistance by altering PKC-θ subcellular localization in rodents. J Clin Invest. 2009;119(9):2577–2589
- Cater et al. 2001. Behenic acid is a cholesterol-raising saturated fatty acid in humans. American Journal of Clinical Nutrition. 73(1): 41-44.