We’ve all heard the term “good fat” and “bad fat”, and we know it’s important to avoid trans-fat and most saturated fats, and include the good fats, monounsaturated and polyunsaturated fats like the essential fatty acids Omega-3 and Omega-6, but do we really understand why “good fats” are so good for us?
Fats are a must. There is a reason omega-3 and omega-6 are considered essential, the body cannot produce them so they must be sourced from your diet. One simple reason to include fats in your diet is that, many vitamins such as A, D, E and K are considered fat-soluble, meaning you need the fat in your diet in order to absorb them.
Monounsaturated fats specially have been found to increase the effectiveness of a cholesterol lowering diet by increasing HDL cholesterol and reduce LDL cholesterol levels (HDL = the “good” one) which corresponds to a reduction in the risk of cardiovascular disease by over 20% (Jenkins et al. 2010). Many sources of monounsaturated fats are also high in other beneficial nutrients such as Vitamin E (National Institutes of Health 2013) and antioxidants like flavonoids (Geleijnse & Hollman 2008) which further boost the potential for heart health.
Some great sources of monounsaturated fats to include in your diet are; avocados, olive oil, avocado oil, cod liver oil, macadamia nut oil, olives, almonds, cashews, brazil nuts, macadamia nuts, hazelnuts, pecans, pistachios, sesame seeds, sunflower seeds, flaxseeds and pumpkin seeds. Fish is also generally considered a source of polyunsaturated fatty acids like Omega-3, however some fish like pickled herring, halibut, sablefish and mackerel are sources of monounsaturated fatty acids as well.
Omega-3 polyunsaturated fatty acids are essential fatty acids needed in the diet in order to help the body to control blood clotting and build cell membranes in the body. Omega-3 can come in many forms however the most common are the alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA is particularly important as the body can generally use this form and convert it to other types of Omega-3 like EPA and DHA (Sacks 2014). Some great foods to consume high in Omega-3s include flaxseeds and flaxseed oil, chia seeds, walnuts, fish particularly salmon fresh and tinned, mackerel, tinned sardines, tinned tuna, & trout.
Omega-6 polyunsaturated fatty acids are another essential fatty acid needed in the diet. Similar to Omega-3’s, Omega-6 are crucial for brain function and normal growth and development. Linoleic acid (LA) a form of Omega-6 is converted to gamma-linolenic acid (GLA) in the body. Omega-6 are also helpful in lowering LDL cholesterol levels, boosting HDL cholesterol and improving the bodies reaction to insulin and therefore keeping sugar levels under control (Harvard Heart Letter 2009). Omega-6 is often quite high in a western diet as it is found mostly in vegetable oils. Safflower oil, sunflower oil, corn oil, soybean oil, sunflower seeds, walnuts and pumpkin seeds are all good sources of Omega-6 fatty acids. It is however generally recognised that a greater intake of Omega-3 fatty acids is needed to help balance the existing high intake of omega 6 (Harvard Heart Letter 2009), although if you are already consuming a healthy eating, balanced diet, lower in processed foods, the chances are that you are not overindulging in the omega 6 containing oils.
Just as a final parting gift, to throw a spanner in the works, while most saturated fats are recognised as bad fats, it is important to mention that not all saturated fats can be called bad. Coconut oil is classified as a saturated fat and therefore in this group, however, the Lauric acid of coconut oil has in fact been found to have a favourable effect on total cholesterol as it increases the HDL concentrations (Mensink et al. 2003).
Ehrlich, S 2011, Omega-6 fatty acids, University of Maryland Medical Center, viewed 4 June 2014, https://umm.edu/health/medical/altmed/supplement/...
Geleijnse, J & Hollman, P 2008, ‘Flavonoids and cardiovascular health: which compounds, what mechanisms?’,American Society of Clinical Nutrition, vol. 88, no. 1, pp. 12-13, viewed 3 June 2014,http://ajcn.nutrition.org/content/88/1/12.full
Harvard Heart Letter 2009, ‘No need to avoid healthy omega-6 fats’, Harvard Health Publications, viewed 4 June 2014, <www.ebscohost.com>
Jenkins, D, Chiavaroli, L, Wong, J, Kendall, C, Lewis, G, Vidgen, E, Connelly, P, Leiter, L. Josse, R & Lamarche, B 2010, ‘Adding monounsaturated fatty acids to a diet portfolio of cholesterol-lowering foods in hypercholesterolemia’,Canadian Medical Association Journal, vol. 182, no. 18, pp. 1961-1967, viewed 3 June 2014, <www.ebscohost.com>
Mensink R, Zock P, Kester A & Katan M 2003 ‘Effects of dietary fatty acids and carbohydrates on the ratio of serum total to HDL cholesterol and on serum lipids and apolipoproteins: a meta-analysis of 60 controlled trials’, American Journal of Clinical Nutrition, vol. 77, no. 5, pp. 1146-1155, viewed 3 June 2014,http://ajcn.nutrition.org/content/77/5/1146.long
National Institutes of Health 2013, Vitamin E – Fact Sheet for Health Professionals, viewed 3 June 2014,http://ods.od.nih.gov/factsheets/VitaminE-HealthProfessional/
Sacks, F 2014, Ask the Expert: Omega-3 Fatty Acids, Harvard School of Public Health, viewed 4 June 2014,http://www.hsph.harvard.edu/nutritionsource/omega-3/