Fat is an essential and necessary component of a healthy diet. As with all food groups, there are healthy fats and there are bad fats. Some fats can cause inflammation and poor health. Whereas other fats can fight against inflammation and contribute to optimal health.
It is known for instance that a diet deficient in essential fats also called essential fatty acids can very quickly cause dry, scaly and eczematous skin1. While some fats are non-essential and can be made by the human body from other foods, certain other fats are essential meaning the human body has no fallback mechanism to account for a dietary deficiency.
There are 5 key types of fat found in food;
- Saturated fats
- Monounsaturated fats
- Polyunsaturated fats
- Trans fats – mostly made via artificial mechanisms
Health experts largely agree monounsaturated and polyunsaturated fats confer large health benefits with both of these groups being inclusive of the most talked about types of fats – omegas 3, 6 and 9.
What is an omega fatty acid?
Fatty acids are molecules made up from elements of carbon, hydrogen, and oxygen. What makes one fatty acid different from another is the amount of these elements it contains as well as how these elements are bonded together. Think of 5 people stood in a chain holding hands, now think of 5 people stood in a chain but with 2 people holding each other’s shoulders instead of their hands. This visually represents what is meant by mono and poly-unsaturated acids.
Monounsaturated acids have 1 double bond i.e. 2 carbon atoms are holding hands at their shoulders – this is a tighter and more ridged bond, whereas polyunsaturated acids have over 1 double bond i.e. more than 2 carbon atoms are holding hands at their shoulders.
Note: Double bonds found in mono a polyunsaturated fatty acids are prone to reaction with oxygen meaning they’re more easily oxidised.
As omega fatty acids are also ‘acids’ at the end of a carbon and hydrogen chain, there comes an ‘acid group’ which in scientific terms is referred to as a carboxylic acid group i.e. it has a carbon double bonded to an oxygen with the same carbon also being bonded to an –OH alcohol group.
The naming of omega acids i.e. omega 3 or omega 6 refers to the position of the first double bond/place of unsaturation/first shoulder hold. This is counted from the side of the molecule farthest away from the acid group. Therefore an omega 3 fatty acid will have a double bond/2 carbon atoms shoulder holding from the 3rd carbon atom. An omega 6 fatty acid will have a double bond also being the first double bond from the 6th carbon atom and so on.
While only certain types of omega 6 fatty acids are considered essential fatty acids, there is an argument for omega 3 fatty acids also being essential. For great health, it matters which a person eats and in what ratio.
NOTE: An essential fatty acid is a fatty acid the body cannot self-synthesise from food. An essential fatty acid has to be eaten and absorbed directly from a person’s diet.
The Importance and health benefits of omega 3 fatty acids
Finding great health and therefore having great overall body and skin health relies on feeding the human body what it’s evolved to eat, digest and make use of. Dairy is a classic example of a food group humans are still evolving to digest with up to 65% of the global population having some form of intolerance. Dairy was not naturally and consistently available to humans after infancy, meaning many adults lack the lactase enzyme needed to break down lactose2. This, therefore, causes health, skin and digestion troubles.
Conversely, omega 3 has always been a prominent feature of a natural human diet with sources suggesting humans have evolved on a diet with a ratio of omega 3 to omega 6 of 1:13. This is an important fact to take note of as a modern diet now contains an average ratio of between 1: 10 and 1: 25. This is in large part due to the invention of commercial oil extraction methods which make it possible to make vegetable oil – a high source of omega 6 oils.
The most prominent and most important types of omega 3 fatty acids are;
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
- Alpha-linolenic acid (ALA)
Omega 3 fatty acids are associated with anti-inflammatory benefits and therefore may be useful in preventing or managing existing inflammatory health risks and diseases such as;
- Heart disease
- Crohn’s disease
- Inflammatory bowel disease
- Ulcerative colitis
In fact, many placebo-controlled trials infer omega-3 has a significant benefit towards the treatment of chronic inflammatory diseases i.e. symptoms are reduced and patients no longer need high doses of anti-inflammatory medicines4.
Interestingly the first moment scientists took interest in the health benefits of omega 3 fatty acids was as a result of epidemiological observations which showed the incidence of inflammatory conditions such as psoriasis, asthma, type 1 diabetes and multiple sclerosis were significantly lower or absent in populations of Greenland Eskimos compared with matching gender and age groups in Denmark5. An interesting discovery as many of these diseases are characterised by inappropriate activation of immune responses.
Below are a selection of study results supporting the wide-ranging health benefits of omega 3 fatty acids;
- Intake of omega 3 fatty acids are associated with heart disease reduction, an effect thought to be a result of their ability to lower heart rate, blood pressure, platelet aggregation and triglyceride levels6.
- Omega 3 supplementation of patients with psoriasis shows a ‘clear and statistically significant improvement’ towards reducing scalp lesions, pruritus, erythema and scaling7,8.
- Adequate omega 3 intakes/omega 3 supplementation may help prevent against age-related brain deterioration. Specifically a diet rich in DHA – the main omega 3 fatty acid found in brain cell membranes. DHA deficiency has been associated with memory impairment and emotional disturbances9.
- Omega 3 supplementation may have therapeutic benefits in childhood depression10.
- Increased omega 3 intake is associated with reduced risk of Alzheimer’s disease. Amyloidosis is a feature of Alzheimer’s disease and also multiple sclerosis, the name refers to a protein build-up which makes it difficult for organs to function appropriately. Studies show omega 3 supplementation could be protective against amyloid production and accumulation11.
- Omega 3 supplementation shows benefit as an adjunctive treatment for joint pain associated with rheumatoid arthritis and inflammatory bowel disease12.
- EPA may help protect against diabetes by preventing and reversing insulin resistance13.
- 10 weeks of omega 3 supplementation (equal amounts of EPA & DHA) has been shown to significantly decrease inflammatory and non-inflammatory acne lesions14, whereas another study showed supplementation with fish oil containing 930mg EPA showed significant overall improvement in severity of acne15, this may be because of EPAs ability to compete with omega 6 fatty acids for metabolism – a point discussed in depth soon.
Which Omega 3 fatty acid is the most important?
The 3 most important omega 3 fatty acids have varying effects and health benefits, it’s important to understand the difference. Some are most beneficial for inflammatory diseases whereas others are most beneficial for brain health. Some are also inferred to have a potential inflammatory effect making it very important to get omega 3 dosing the correct way round.
Eicosapentaenoic acid (EPA) is a type of omega 3 most associated with helping to reduce inflammation. Interestingly it looks possible that EPAs main mode of action may be competitive metabolism with an omega 6 fatty acid (arachidonic acid (AA)). This omega 6 fatty acid can be used to synthesise inflammatory mediators however EPA can compete with AA for metabolism. Meaning EPA has an anti-inflammatory effect because it’s less inflammatory than AA16. Therefore while EPA is an important omega 3 fatty acid, what may be most important for long-term health is careful control of a person’s EPA/omega 3 to omega 6 ratio.
Docosahexaenoic acid (DHA) is an omega 3 fatty acid found abundantly in brain tissue and is most associated with helping to protect and promote normal brain function. In contrast to EPA, DHA is actively anti-inflammatory and is studied to be much more potently anti-inflammatory than EPA17.
Alpha-linolenic acid (ALA) is an omega 3 fatty acid used predominately as energy, it may also be converted into EPA or DHA, however, this conversion is not efficient. Indeed ALA conversion is not efficient enough to provide beneficial health benefits18. ALA is the major source of omega 3 fatty acids for people following a plant-based diet.
Can Omega 3 fatty acids be found in a vegetarian/vegan diet?
While DHA and EPA are not termed essential fatty acids meaning they can be synthesised from other ingredients, it is clear the major synthesis pathway i.e. ALA to DHA or EPA is not sufficient to provide optimal health benefits. Indeed scientists and healthcare professionals are inclined to label DHA and EPA as essential for this reason.
ALA is largely and easily found in a plant-based diet. Some of the highest food sources of ALA include;
- Flaxseeds and flaxseed oil – the richest source
- Pumpkin seeds
- Rapeseed oil
- Soybean oil
Conversely, DHA and EPA are not as easy to find in a vegetarian or vegan diet because the most prominent food sources are;
- Algae – note: this is specific types of algae
- DHA enriched eggs
A 2013 study concludes plasma/blood levels of EPA and DHA are significantly lower in vegetarians but to date, the health implications of this are not known. The same study suggested vegetarians should take steps to optimise the conversion of ALA to EPA and DHA by reducing their intake of linoleic acid e.g. safflower oil, evening primrose oil, sunflower oil. If going through pregnancy or experiencing a chronic disease, it is suggested a daily supplement of microalgae (200-300mg/day) may be beneficial19.
The Importance & health benefits of omega 6 fatty acids
Omega 6 fatty acids can be beneficial for great health in moderation with the key being in moderation. As mentioned before humans evolved on a near 1 to 1 ratio of omega 3 to omega 6 however nowadays the average consumption of omega 6 outweighs omega 3 by over 10 to 1. Omega 6 fatty acids are polyunsaturated and unlike omega 3 fatty acids they are essential i.e. the human body cannot make omega 6 from other dietary nutrients.
Some of the most talked about/most important omega 6 fatty acids include;
- Linoleic acid
- Linolenic acid
- For best health effects a type of linolenic acid called gamma-linolenic acid
Note: The above fatty acids are both essential, they’re also the only currently and technically accepted essential fatty acids.
A correct ratio of omega 6 fatty acids to omega 3 fatty acids is associated with improved health outcomes, for instance;
- In the prevention of cardiovascular disease a 4:1 omega 6: omega 3 ratio was associated with a 70% decrease in total mortality.
- A 2.5: 1 ratio reduced rectal cancer cell proliferation, whereas a 4: 1 ratio had no effect.
- A lower omega 6: omega 3 ratio in women with breast cancer has been associated with decreased risk.
- The inflammation associated with rheumatoid arthritis was significantly suppressed on an omega 6 to omega 3 ratio of 2-3/1
- In patients with asthma an omega ratio of 5:1 had benefits, whereas the more commonly consumed ration of 10: 1 had adverse effects20.
The ratio of omega 6 to omega 3 is thought to be particularly important because omega 6 fatty acids can inhibit tissues from up taking both DHA and EPA. Therefore high omega 6 intake can result in low omega 3 levels21.
While omega 6 fatty acids are essential for optimal health and especially optimal skin health, having too many of them in your diet or having significantly more of them than omega 3 fatty acids is associated with poor health outcomes.
The below foods are omega 6 rich;
- Safflower oil
- Sunflower oil
- Corn oil
- Cottonseed oil
- Sesame seed oil
- Peanut oil
- Soybean oil (having an omega 6:3 ration of 51:7%)
- Walnuts (having an omega 6:3 ration of 52:10%)
Which in contrast makes the best food source for managing a healthy omega 3 to omega 6 ratio – fish. Averagely fish has 0% omega 6 but is packed with omega 3.
While many other foods contain both omega 6 and omega 3, their ratios can significantly differ. This is a consequence of natural foods. For instance, a Greek egg can contain an omega 6 to 3 ratio of 1:3 whereas a supermarket egg can contain a ratio of 19:922.
Why most people’s diets contain more omega 6 than omega 3
Until recently oil was most naturally made by pressing olives or even avocados, however, the invention of commercial pressing machines has seen the advent of vegetable oil. Processes which extract oil from seeds with intense pressure and sometimes heat. Due to this commercialisation vegetable oil is cheap and readily available which means the below are common sources of omega 6 fats;
- Fried foods – foods are most often fried in sunflower oil
- Cereal bars
- Raisins which are part re-hydrated with sunflower oil
- Ready meals
- Salad dressings
Olive oil or flaxseed oil may, therefore, be better for long-term health. Flaxseed oil because of its high omega 3 content – although it should be noted this is in the form of ALA, and Olive oil because of its relatively low omega 6 content. Olive oil is mostly comprised of omega-9 fatty acids (>68%) with small amounts of omega 6 fatty acids. Interestingly the Mediterranean diet, which is high in olive oil and fish is associated with significant health benefits23.
The most prudent way to benefit from current scientific learnings of omega 6 to omega 3 ratios is to ration common omega 6 high food sources with an additional focus on eating omega 3 rich foods. For most people, this would mean restricting consumption of ready-made foods while increasing consumption of fatty fish.
The Importance & health benefits of omega 9 fatty acids
In contrast to omega 3 and 6 fatty acids which are polyunsaturated, omega 9 fatty acids are monounsaturated. Rather than interacting with immune function, omega 9 fatty acids are thought to be used mostly as an energy source. The most common type of omega 9 fatty acid is oleic acid which is the major component of olive oil.
A diet rich in monounsaturated fatty acids is associated with the following health outcomes;
- A positive reduction in bad cholesterol (LDL) in diabetes patients24.
- A protective and reversing effect on insulin resistance, a common cause of type 2 diabetes25
- Reduction in all-cause mortality by 11%, cardiovascular mortality by 12%, cardiovascular events by 9% and stroke by 17% – however, this study notes omega 9 benefits may be solely attributable to olive oil benefits – a rich source of omega 9 which also contains potent phenolic antioxidant components26
The healthiest source of omega 9 fatty acids is olive oil with avocados and avocado oil being a close second. Both olive and avocado oils are particularly stable meaning they’re very appropriate to be used as cooking oils. Conversely, omega 3 and omega 6 rich oils, being polyunsaturated are prone to oxidation which may be speeded through cooking. Indeed many vegetable oils have a low smoke point27.
Are omega supplements effective?
If it is hard to source a regular and good quality of fish, supplementation with omega oils can serve as a useful method of dietary balance. There are 3 kinds of omega supplements widely available;
- Omega 3 supplements containing both EPA and DHA
- Omega 3 supplements containing only DHA – most common from algae oil
- Omega 3, 6 & 9 supplements
Sources of both omega 6 and 9 fatty acids are widely available in modern diets and therefore combined omega supplements are largely not necessary or helpful. Supplements containing only omega 3, therefore, have the most potential for positive effect.
In addition, DHA exerts a much stronger anti-inflammatory effect than EPA, therefore if following a diet low in omega 6 fatty acids (because EPA competes with a certain omega 6 fatty acid for metabolism) the consideration of DHA only omega 3 supplements is very valid.
The best omega supplements
When selecting an effective omega supplement it’s important to choose one which takes measures to protect delicate omega 3 oils from oxidation. Omega 3 oils are polyunsaturated meaning they’re most vulnerable to attack from oxygen exposure – a process which is speeded by high heat.
High-quality omega 3 supplements will, therefore, be cold pressed instead of using heated extraction methods. A cold pressing ensures minimal oxidation of omega 3 fatty acids. They should also contain a partnering antioxidant such as vitamin E. The presence of an antioxidant prevents polyunsaturated omega 3 fatty acids from oxidation.
The bottom line: Omega 3 is the most important out of all omega fatty acids with studies suggesting DHA out of all omega 3 fatty acids show the most potent anti-inflammatory effects. An average modern diet contains too many sources of omega 6 fatty acids and too little omega 3 fatty acids. Therefore care should be taken to reduce omega 6 sources while increasing consumption of omega 3.
- Prottey C, The British Journal of Dermatology [01 May 1976, 94(5):579-585] DOI: 10.1111/j.1365-2133.1976.tb05151.x
- Omega-3 fatty acids in health and disease and in growth and development, The American Journal of Clinical Nutrition, Volume 54, Issue 3, 1 September 1991, Pages 438–463, https://doi.org/10.1093/ajcn/54.3.438
- Artemis P. Simopoulos (2002) Omega-3 Fatty Acids in Inflammation and Autoimmune Diseases, Journal of the American College of Nutrition, 21:6, 495-505, DOI: 10.1080/07315724.2002.10719248
- Epidemiological studies in the Upernavik district, Greenland. Incidence of some chronic diseases 1950-1974. Kromann N, Green A. Acta Med Scand. 1980;208(5):401-6.
- Omega-3 fatty acids and coronary heart disease risk: clinical and mechanistic perspectives. Harris WS, Miller M, Tighe AP, Davidson MH, Schaefer EJ. Atherosclerosis. 2008 Mar;197(1):12-24. Epub 2007 Dec 26. Review.
- n-3 polyunsaturated fatty acids supplementation in psoriasis: a review, Naiara Lourenço Mari, Andréa Name Colado Simão and Isaias Dichi, Nutrire 2017 42:5, https://doi.org/10.1186/s41110-016-0029-3
- Study on the use of omega-3 fatty acids as a therapeutic supplement in treatment of psoriasis, clinical, cosmetic and investigational dermatology, 17 May 2011
- Omega-3 fatty acids and brain resistance to ageing and stress: body of evidence and possible mechanisms. Denis I, Potier B, Vancassel S, Heberden C, Lavialle M. Ageing Res Rev. 2013 Mar;12(2):579-94. doi: 10.1016/j.arr.2013.01.007. Epub 2013 Feb 6. Review.
- Omega-3 Treatment of Childhood Depression: A Controlled, Double-Blind Pilot Study, Hanah Nemets et al.
- A Diet Enriched with the Omega-3 Fatty Acid Docosahexaenoic Acid Reduces Amyloid Burden in an Aged Alzheimer Mouse Model Giselle P. Lim, Frédéric Calon, Takashi Morihara, Fusheng Yang, Bruce Teter, Oliver Ubeda, Norman Salem, Sally A. Frautschy and Greg M. Cole Journal of Neuroscience 23 March 2005, 25 (12) 3032-3040; DOI: https://doi.org/10.1523/JNEUROSCI.4225-04.2005
- A meta-analysis of the analgesic effects of omega-3 polyunsaturated fatty acid supplementation for inflammatory joint pain. Robert J. Goldberg, Joel Katz Pain. 2007 May; 129(1-2): 210–223. Published online 2007 Mar 1. doi: 10.1016/j.pain.2007.01.020
- Kalupahana, N. S., Claycombe, K., Fletcher, S., Wortman, P., and Moustaid-Moussa, N. (2010a). Eicosapentaenoic acid improves adipose tissue inflammation in part via downregulation of adipose angiotensinogen secretion. Obesity 18 (S71-S).
- Effect of dietary supplementation with omega-3 fatty acid and gamma-linolenic acid on acne vulgaris: a randomised, double-blind, controlled trial. Jae Yoon Jung, Hyuck Hoon Kwon, Jong Soo Hong, Ji Young Yoon, Mi Sun Park, Mi Young Jang, Dae Hun Suh Acta Derm Venereol. 2014 Sep; 94(5): 521–525. doi: 0.2340/00015555-1802
- Effects of fish oil supplementation on inflammatory acne Golandam Khayef, Julia Young, Bonny Burns-Whitmore, Thomas Spalding Lipids Health Dis. 2012; 11: 165. Published online 2012 Dec 3. doi: 10.1186/1476-511X-11-165
- Risk stratification by the “EPA+DHA level” and the “EPA/AA ratio” focus on anti-inflammatory and antiarrhythmogenic effects of long-chain omega-3 fatty acids. Heinz Rupp, Daniela Wagner, Thomas Rupp, Lisa-Maria Schulte, Bernhard Maisch Herz. 2004 Nov; 29(7): 673–685. doi: 10.1007/s00059-004-2602-4
- Anti-inflammatory effects of EPA and DHA are dependent upon time and dose-response elements associated with LPS stimulation in THP-1-derived macrophages. Anne Mullen, Christine E. Loscher, Helen M. Roche, J Nutr Biochem. 2010 May; 21(5): 444–450. Published online 2009 May 8. doi: 10.1016/j.jnutbio.2009.02.008
- Health benefits of n-3 polyunsaturated fatty acids: eicosapentaenoic acid and docosahexaenoic acid.
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- The importance of the ratio of omega-6/omega-3 essential fatty acids. A. P. Simopoulos, Biomed Pharmacother. 2002 Oct; 56(8): 365–379.
- Conversion of linoleic acid and alpha-linolenic acid to long-chain polyunsaturated fatty acids (LCPUFAs), with a focus on pregnancy, lactation and the first 2 years of life. Robert A. Gibson, Bev Muhlhausler, Maria Makrides
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- M. Al-Bachir & H. Sahloul (2017) Fatty acid profile of olive oil extracted from irradiated and non-irradiated olive fruits, International Journal of Food Properties, 20:11, 2550-2558, DOI: 10.1080/10942912.2016.1243557
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- Monounsaturated fatty acid-enriched high-fat diets impede adipose NLRP3 inflammasome-mediated IL-1β secretion and insulin resistance despite obesity. Orla M. Finucane, Claire L. Lyons, Aoife M. Murphy, Clare M. Reynolds, Rut Klinger, Niamh P. Healy, Aoife A. Cooke, Rebecca C. Coll, Liam McAllan, Kanishka N. Nilaweera, et al. Diabetes. 2015 Jun; 64(6): 2116–2128. Published online 2015 Jan 27. doi: 10.2337/db14-1098
- Monounsaturated fatty acids, olive oil and health status: a systematic review and meta-analysis of cohort studies, Lukas Schwingshackl et al, Lipids in Health and Disease201413:154, https://doi.org/10.1186/1476-511X-13-154
- Stability of avocado oil during heating: comparative study to olive oil. Izaskun Berasategi, Blanca Barriuso, Diana Ansorena, Iciar Astiasarán, Food Chem. 2012 May 1; 132(1): 439–446. Published online 2011 Nov 12. doi: 10.1016/j.foodchem.2011.11.018