Archive for Nutrition

Coconut Oil: What’s Up with Fat?

In June, we shared some thoughts and additional studies on the coconut oil and saturated fat controversy that recently took the Internet by storm. Several experts in the field have also taken the time to share their perspectives on the risks associated with substituting saturated fats like coconut oil for polyunsaturated fatty acids (PUFAs) in our diets, particularly omega-6 PUFAs in highly refined “vegetable oils” such as canola and soy oil, etc. (see Hyman, Davis, and Perlmutter). These experts and others have also identified issues with the methodology underlying the guidelines created by the American Heart Association (AHA) to consume less saturated fat (see also Bastian and Bastian).

In general, HCB2 is not opposed to the inclusion of omega-3 and omega-6 fatty acids (PUFAs) as part of a diet based primarily on real, whole, and anti-inflammatory foods. These fats are essential to the many processes the body undertakes everyday to keep us well and functioning.1 We also agree with the AHA and others that replacing overall dietary fat intake with additional carbohydrates fails to result in reduced LDL cholesterol levels and also fails to support overall health and wellbeing in general.2 In addition, we agree that trans fats, which are required to be out of the food supply by summer 2018, should also be avoided.3

HCB2 General Dietary Guidelines on Coconut Oil and Other Saturated Fats

We differ on the advice offered by AHA in several ways:

1) HCB2 encourages that people continue to smartly consume quality saturated fats (e.g. coconut, virgin coconut oil, butter/ghee, etc.) because these fats are shown to have positive health effects on HDL (“good” cholesterol), gut integrity and cancer, patient quality of life, and more.4, 8-15, 25

  • Studies have found virgin coconut oil increases HDL (“good”) cholesterol and helps to decrease body mass and waist circumference as well as offer other beneficial effects on cholesterol levels.8-9
  • Several studies, including at least 2 meta-analysis studies, found that saturated fat does not appear to be associated with cardiovascular disease events nor all-cause mortality.10-13
  • Virgin coconut oil has been shown to improve quality of life and reduce chemotherapy side effects for breast cancer patients.14
  • In at least one animal study, researchers found that diets high in saturated fats (including coconut oil) reduced inflammation, tumor burden and colon cancer cell proliferation. It also increased colon cancer cell apoptosis. These results may be due to increased expression of a particular gene (Muc2) that has been shown to strengthen the integrity of the intestinal wall.15
  • Loss of this same gene expression (Muc2), which was shown to have increased expression with a saturated fat diet, has also been connected to colon cancer in humans, and its loss may also be a predictor of poor colon cancer disease outcomes in addition to cancer reoccurrence.16-17

salmon2) We encourage that saturated fats be consumed with other quality foods, including lower-glycemic carbohydrate sources (e.g. veggies and fruits). Refined sugars and other highly processed carbohydrates should generally be avoided as they are often lacking in quality nutrients and can add to the inflammatory burden placed on the body.4, 13, 23-24

  • One additional analysis examining dietary recommendations found there to be little or weak evidence linking saturated fats to coronary artery disease and other conditions. Instead, there is evidence linking sugars and the oxidation/over-heating of PUFAs (including possibly to some extent the small   amounts of PUFAs found in foods consisting primarily of saturated fats) to bodily inflammation and disease such as heart disease, cancer, type 2 diabetes and more.13
  • Another recent study found that it is added sugars in highly processed foods, which may also contain some saturated fats, that increase coronary heart disease (CHD) and other conditions. The authors strongly advocate for diets based primarily on whole, real foods.23

Time for an Oil Change: Avoid Heavily Refined and Inflammatory Vegetable Oils

olive oil3) We strongly encourage that people avoid cooking with unsaturated fats (PUFAs) as they can become oxidized during the cooking process and therefore can contribute to bodily inflammation. We also do not advocate for the consumption of “vegetable” oils (e.g. canola, corn, soy, sunflower, safflower, etc.) overall given evidence that these oils are already oxidized and inflammatory before they are heated due to how they are processed and stored.5-6, 13

4) There is also concern that regular intake of “vegetable” oils high in omega-6 PUFAs affects the omega-6 to omega-3 fat ratio in the body, which may contribute to various inflammatory health conditions, including obesity, heart disease, cancer and diabetes.7, 12, 18-22, 25-27

  • Several studies link the consumption of PUFAs, particularly those higher in  omega-6 fatty acids in comparison to omega-3 fatty acids, to increased risk of breast and colorectal cancers.18-20, 26
  • At least one systematic review shows no reduced risk of cardiovascular events and related-mortality by substituting PUFAs, particularly omega-6 PUFAs, in place of saturated fats.21 Another more recent study examining outcomes from randomized control trials also comes to the conclusion that replacement of saturated fats with omega-6 PUFAs is unlikely to reduce cardiovascular-related events  and all cause mortality.22

HCB2 “Bottom” Line:

Focus on consuming more real, whole, and anti-inflammatory foods, which may naturally contain a spectrum of fatty acids, including saturated, PUFA (with particular emphasis on omega-3 fatty acids) and MUFA fats.

5) In regard to intake of unsaturated fats (PUFAs) overall, we encourage that people consume them from wild caught fish, raw whole avocado, and raw and sprouted nuts and seeds instead of “vegetable” oils. We also advocate for the consumption of monounsaturated fats (MUFAs) from olives and unheated virgin olive oil as well as avocados and some raw and sprouted nuts. 

Please see our Fight Right Anti-Inflammatory Grocery List for more information and suggestions.

References

  1. University of Maryland Medical Center (UMM). (2015). Omega-6 fatty acids. Retrieved June 23, 2017 from http://www.umm.edu/health/medical/altmed/supplement/omega6-fatty-acids.
  2. Sacks F., Lichtenstein A., Wu J., Appel L. et al. (2017). Dietary fats and cardiovascular disease: a presidential advisory from the American Heart Association. Circulation, 135(25). http://circ.ahajournals.org/content/early/2017/06/15/CIR.0000000000000510.
  3. FDA. (2015). Final Determination Regarding Partially Hydrogenated Oils (Removing TransFat).  Retrieved June 23, 2017 from https://www.fda.gov/food/ingredientspackaginglabeling/foodadditivesingredients/ucm449162.htm.
  4. Hyman, Mark MD. 2016. Is Coconut Oil Bad for Your Cholesterol? Retrieved June 23, 2017 from http://drhyman.com/blog/2016/04/06/is-coconut-oil-bad-for-your-cholesterol/.
  5. Halvorsen B. & Blomhoff R. (2011). Determination of lipid oxidation products in vegetable oils and marine omega-3 supplements. Food Nutr Res, 55. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3118035/.
  6. Choe E. & Min D. (2016). Mechanisms and Factors for Edible Oil Oxidation. Comprehensive Reviews in Food Science and Food Safety, 5: 169–186. http://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2006.00009.x/abstract.
  7. Patterson E., Wall R., Fitzgerald GF, Ross RP et al. (2012). Health Implications of High Dietary Omega-6 Polyunsaturated Fatty Acids. J Nut Metab  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3335257/#!po=30.1724.
  8. Cardoso DA, Moreira A, deOliveira GMM, Luiz RR et al. (2015). A coconut extra virgin oil-rich diet increases HDL cholesterol and decreases waist circumference and body mass in coronary artery disease patients Nutrición Hospitalaria, 32(5): 2144-2152. https://www.ncbi.nlm.nih.gov/pubmed/26545671.
  9. Lekshmi D, Nazeem P, Narayanankutty A, Manalil J et al. (2016). In Silico and Wet Lab Studies Reveal the Cholesterol Lowering Efficacy of Lauric Acid a Medium Chain Fat of Coconut Oil. Plant Foods for Human Nutrition, 71(4): 410-415. https://www.ncbi.nlm.nih.gov/pubmed/27679437.
  10. de Souza R, Mente A, Maroleanu A, Cozma A et al. (2015). Intake of saturated and trans unsaturated fatty acids and risk of all cause mortality, cardiovascular disease, and type 2 diabetes: systematic review and meta-analysis of observational studies. BMJ. http://www.bmj.com/content/351/bmj.h3978.
  11. Siri-Tarino P, Sun Q, Hu F & Krauss, R (2010). Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. American Journal of Clinical Nutrition, 91: 535-46. https://www.ncbi.nlm.nih.gov/pubmed/20071648.
  12. DiNicolantonio, J (2014). The cardiometabolic consequences of replacing saturated fats with carbohydrates or [omega]-6 polyunsaturated fats. Do the dietary guidelines have it wrong? Open Heart, 1(1). http://openheart.bmj.com/content/1/1/e000032.
  13. Lawrence, G. (2013). Dietary Fats and Health: Dietary Recommendations in the Context of Scientific Evidence. Advances in Nutrition, 4: 294-302. http://advances.nutrition.org/content/4/3/294.full.
  14. Law K, Azman N, Omar E, Musa M et al. (2014). The effects of virgin coconut oil (VCO) as supplementation on quality of life (QOL) among breast cancer patients. Lipids in Health and Disease, 13:139. https://www.ncbi.nlm.nih.gov/pubmed/25163649.
  15. Enos RT, Velázquez KT, McClellan JL, Cranford TL et al. (2016). High-fat diets rich in saturated fat protect against azoxymethane/dextran sulfate sodium-induced colon cancer. American Journal of Physiology – Gastrointestinal and Liver Physiology, 310(11). https://www.ncbi.nlm.nih.gov/pubmed/27033117.
  16. Mizoshita T, Tsukamoto T, Inada KI, Hirano N et al. (2007). Loss of MUC2 expression correlates with progression along the adenoma-carcinoma sequence pathway as well as de novo carcinogenesis in the colon. Histology and Histopathology, 22(3):251-60. https://www.ncbi.nlm.nih.gov/pubmed/17163399.
  17. Elzagheid A,  Emaetig F,  Buhmeida A,  Laato M et al. (2013). Loss of MUC2 expression predicts disease recurrence and poor outcome in colorectal carcinoma. Tumor Biology, 34(2): 621-8. https://www.ncbi.nlm.nih.gov/pubmed/23179399.
  18. Murff HJ, Shu XO, Li H, Dai Q et al. (2009). A prospective study of dietary polyunsaturated fatty acids and colorectal cancer risk in Chinese women. Cancer Epidemiol Biomarkers Prev, 18(8). https://www.ncbi.nlm.nih.gov/pubmed/19661088.
  19. Murff HJ, Shu XO, Li H, Yang G et al. (2011). Dietary polyunsaturated fatty acids and breast cancer risk in Chinese women: a prospective cohort study. Int J Cancer, 128(6): 1434-41. https://www.ncbi.nlm.nih.gov/pubmed/20878979.
  20. Reddy, BS. (2002). Types and amount of dietary fat and colon cancer risk: Prevention by omega-3 fatty acid-rich diets. Environ Health Prev Med, 7(3): 95-102. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2723490/.
  21. Schwingshackl, L & Hoffmann, G. (2014). Dietary fatty acids in the secondary prevention of coronary heart disease: a systematic review, meta-analysis and meta-regression. BMJ Open, 4(4). http://bmjopen.bmj.com/content/4/4/e004487.long.
  22. Hamley, S. (2017). The effect of replacing saturated fat with mostly n-6 polyunsaturated fat on coronary heart disease: a meta-analysis of randomised controlled trials. Nutrition Journal, 16(30). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5437600/.
  23. DiNicolantonio, JJ, Lucan, SC and O’Keefe, JH. (2016). The Evidence for Saturated Fat and for Sugar Related to Coronary Heart Disease Prog Cardiovasc Disease, 58(5). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4856550/.
  24. Volk, BM, Kunces LJ, Freidenreich, DJ, Kupchak BR et al. (2014). Effects of Step-Wise Increases in Dietary Carbohydrate on Circulating Saturated Fatty Acids and Palmitoleic Acid in Adults with Metabolic Syndrome. PLoS One, 9(11). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4240601/.
  25. DiNicolantonio JJ, Harcombe Z, and O’Keefe JH. (2016). Problems with the 2015 Dietary Guidelines for Americans: An Alternative. Missouri Medicine, 113(2). https://www.researchgate.net/publication/302873650_Problems_with_the_2015_Dietary_Guidelines_for_Americans_An_Alternative.
  26. Simopoulos, AP. (2008). The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases. Exp Biol Med, 233(6). https://www.ncbi.nlm.nih.gov/pubmed/18408140.
  27. Simopoulos, AP. (2016). An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity. Nutrients, 8(3). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808858/.