Fat facts: a technical guide


OmegasDietary fat can be a quite complicated subject, both for you as a practitioner and for your clients. This guide provides you with all the information you really need to know about fats, our requirements for optimum health, food and supplement sources and how different types of fats compare.

A brief history and negative associations with fats

With such an established bad reputation, we must first of all clear up the reasons for negative associations with fat: a common misunderstanding that, due to the high calorie content of fat per gram, it may contribute to weight gain. Of course we all now know that this is certainly not the case when it comes to weight management. Fat doesn’t make you fat. Although controversial, the Atkins diet may have helped us out on that one. It is now understood that our bodies are well equipped to regulate calorie intake from any macronutrient consumed. Low fat diets are certainly not the most successful for weight loss. (1) This may be partly because an increased consumption of refined carbohydrate may slightly increase appetite due to insulin and ghrelin levels.

High fat diets associated with high cholesterol and high risk of cardiovascular disease has also given fat a bad name. As butter is high in saturated fats, and as saturated fats increase the production of cholesterol in the body, it has been concluded by some that foods such as butter increase risk of heart disease. Recent meta analyses have concluded that there is no significant evidence to show that saturated fat is associated with heart disease. (2) Given the volume of negative information, animal fat consumption has been displaced by a huge increase in vegetable oils and refined fats such as margarine. (A main concern in the development of such products was actually economic – these products have a longer shelf life.) Such messages to reduce intake of saturated fats have backfired in health terms as we have replaced many of these foods with high GI carbohydrates. This has actually increased cardiovascular disease. (3)

Saturated fat and cholesterol are still often both considered to be ‘bad’ for us by some individuals; however, cholesterol is highly important for immune function, hormone production, cell membrane function, digestion, skin health and so much more. A certain amount of saturated fat can be beneficial for us.

In addition to changes in saturated fat consumption, our intake of other fatty acids has also changed considerably. Historically, the human diet was high in omega-3 fatty acids, with a ratio of omega-6 to omega-3 fatty acids of around 1-2:1. During the last few decades, there has been a huge increase in consumption of omega-6 with a corresponding decrease in consumption of omega-3 fatty acids. Many modern food types are ‘new’ in regard to human evolution, rich in added omega-6 and stripped of omega-3.

Health benefits of fats

Fat is of course essential for health in many ways including growth and development, providing the most dense source of energy. Fat very importantly protects organs and body tissues by providing cushioning, supports immune function and regulates inflammation. The functionality of cell membranes depends on fatty acids, and fats aid in the absorption and storage of fat-soluble vitamins A, D, E and K.

The balance of fatty acids omega-3 EPA and omega-6 AA have an important role in the production of anti-inflammatory or pro-inflammatory signalling molecules in the body. (4) EPA is the specific omega-3 fatty acid responsible for reducing inflammation, reducing blood pressure and reducing platelet aggregation, therefore reducing risk of stroke and heart attack. (5) EPA is also particularly important in the proper functioning of the immune system through its production of eicosanoids.

Omega-3 EPA is required for neurotransmitter function, including serotonin, thereby playing a role in brain health. Fatty acids are therefore beneficial for those with depression and bipolar disorder, anxiety, poor memory, difficulty in concentrating and issues with sleeping properly. Studies specifically looking at omega-3 fatty acid levels in red blood cells have found that omega-3 concentration levels are significantly lower in depressed individuals. (6) Chronic low-grade inflammation and a high omega-6 AA : omega-3 EPA ratio is associated with depression. (7)

Omega-3 fatty acids are also required for regulating inflammation in joints and skin and provide fluidity to cells. A high ratio of AA:EPA is associated with a range of chronic inflammatory conditions, including arthritis. (8)

Fatty acid deficiencies

male palm with eczema isolated on white backgroundDeficiency symptoms of fatty acids include visually apparent dry skin, dry hair, splitting nails and dry eyes. Omega-3 deficiency can also result in frequent illness, difficulty in concentrating, irritability, sleep difficulties, aching joints, infertility and much more. A diet low in fat also has a negative effect on health by reducing the amount of fat-soluble vitamins being absorbed; proper absorption is required for immune, skin and bone health.

Common deficiencies exist in individuals with eczema and mood and neurodevelopmental disorders. Children with ADHD have very low blood levels of essential fatty acids, in particular the long-chain omega 3 fatty acid EPA. (9)

Essential fats

The essential fats are those which are required from food as they cannot be made in the body; alpha linolenic acid (ALA) and linoleic acid (LA). Omega-3 ALA is found in linseeds, chia and echium and omega-6 LA is sourced from vegetable oils such as safflower, sunflower and corn oil. Hemp seeds and chia seeds have high amounts of essential fats in healthy ratios. Omega-3 EPA and DHA are not strictly considered essential fats as, with the correct enzyme process, they can be made in the body from the short-chain fatty acids ALA and LA, however if someone is lacking in foods containing these fats, EPA and DHA may be considered essential by some individuals.

Food sources of fats

bigstock-fresh-raw-red-fish-fillet-on-w-49054787Saturated fats are solid at room temperature, are found in foods grown in tropical conditions and also from animal sources. Saturated fats include coconut oil, cocoa butter, palm oil, meat and butter. Plant-based saturated fats such as coconut oil have actually been shown to have a beneficial effect on heart health by increasing healthy HDL cholesterol. (10) In general, if someone is trying to lower their risk of cardiovascular disease and stay healthy, a moderate amount of both animal and plant based saturated fat in the diet is absolutely fine – a certain amount is actually good for you!

Health is not simply related to saturated fat intake and possibly more important is to include plenty of both polyunsaturated and monounsaturated fats in the diet. Research has shown that instead of reducing fat content in the diet, increasing the amount of polyunsaturated and monounsaturated fats, in place of saturated fat, considerably reduces risk of coronary heart disease. (11;12)

Polyunsaturated fats omega-3 EPA and DHA are found in high quantities in oily fish such as salmon, mackerel and herring. White fish such as cod and larger fish such as tuna are commonly eaten in the UK, whilst small oily fish such as herring and mackerel are eaten less frequently. Ideally, we should be consuming more of the small oily fish.

Plant-based polyunsaturated omega-3 fatty acids ALA and SDA can be sourced from linseeds and echium seed oil. Polyunsaturated omega-6 AA is found in meat, grains and eggs, healthy in moderation, but inflammatory in excess. Other omega-6 fats, which can be converted to AA in the body, are sourced from vegetable oils such as sunflower and corn oil. Nuts and seeds also provide a source of omega-6 LA and omega-3 ALA.

Monounsaturated fatty acids include omega-7 and omega-9 fatty acids, found in food sources such as avocados, olives and macadamia nuts.

The fats provided in eggs have caused a stir when it comes to considering cardiovascular health. Although eggs contain fairly high levels of cholesterol, the cholesterol consumed in a typical diet actually has a very small effect on our cholesterol levels, as the majority is made in the liver. Eggs have no significant effect on cardiovascular disease risk (13) and they are a rich source of both antioxidants and B vitamins which are beneficial for heart health. On the whole, it is definitely best to recommend eggs for a healthy heart.

Fatty acid stability, processing and cooking

The common assumption that saturated fats are ‘bad’ for you is flawed; heat-processed trans fats such as margarine are the real enemy.

The manufacturing processes of oil have changed drastically over the last few decades, from cold-pressed oils delivered to your door in small batches, to mechanically pressed with heat in large batches. These processes result in heat-exposed oils, commonly exposed to light and oxygen in clear bottles. A long time on the shelf combined with lower levels of antioxidants in refined oils can also increase rancidity.

Hydrogenated fats undergo a process in which oils are treated under pressure with hydrogen gas at a high temperature. Hydrogenation changes the chemical structure of a fat, making it more solid at room temperature, allowing polyunsaturated fats such as vegetable oil to have a solid ‘spreadable’ texture. Heat processed trans fats are found in foods such as biscuits, crisps and some margarines. Processed and refined vegetable oils found in margarine are likely to cause more damage to the heart compared to the natural saturated fats found in butter and may also increase inflammation.

Healthy polyunsaturated fats can easily become damaged when exposed to heat. Omega-3 EPA and DHA are the most heat unstable. Other omega-3 and 6 fats found in seeds and nuts are easily damaged in heat and should not, therefore, be heated to above 140 deg C. With such information it may be understood why baking fish in the oven is preferable to frying and oils like walnut and sesame seed should only be added cold to food, never heated.

Vegetable oils such as sunflower, high in omega-6, are also easily damaged when exposed to high temperatures, because of oxidation. Olive oil and other monounsaturated fats (high in omega-9) such as rapeseed oil can be safely exposed to slightly higher temperatures, such as frying on a medium heat, or frying with water added to the pan to keep the temperature down. Saturated fats, including coconut oil and butter, are the most stable fats for cooking.

Adding antioxidant and sulphur-rich foods such as onions and garlic when heating oils can additionally help to protect delicate fats from oxidising during cooking. Reusing fats for cooking is extremely unhealthy – reused oil in deep-fried foods should be avoided at all times.

Digestion and metabolism of fatty acids

The digestion process of fat occurs when bile is produced from the liver, emulsifying fat and breaking it down from fat globules to fat droplets. Lipase is an enzyme produced in the mouth, pancreas and small intestine which splits the fatty acids from the glycerol backbone. To optimise absorption of fatty acid supplements, this digestion process occurs when taking supplements with a meal containing fat. If there is difficultly digesting fat, e.g. heartburn, digestive enzyme supplements can be taken to support the breakdown of fat.

Conversion of different types of fatty acids also depends on the function of enzymes required and vitamins and minerals to fuel these processes. Poor enzyme function may result in reduced conversion of plant-based fats such as omega-3 ALA to omega-3 EPA. Zinc, magnesium and vitamin B6 are required by these enzymes.

Top dietary tips for clients

• Add a handful of nuts to snacks
• Sprinkle ground seeds on breakfast or stir into soups
• Have oily fish 1-2 times a week – mackerel, salmon, trout
• Include omega- 3, 6 & 9 fatty acids from walnut and olive oil on salads
• Include other monounsaturated fat-rich foods, such as avocados
• Cook with saturated fats such as coconut oil and butter
• Choose grass-fed meat, ideally organic
• Try to limit intake of omega-6 vegetable oils, which are found in many processed foods such as crisps and biscuits
• To preserve the essential fatty acid EPA in fish when cooking, baking is preferable to frying and fresh wild fish contains the ideal fatty acid ratios

Diagnostic tests to measure fatty acid level status

Diagnostic tests that measure levels of fatty acids in cell membranes are very useful if you are unsure how well an individual may be utilising fats from their diet, or if you believe that their diet is not particularly balanced. If your client has a good intake of fats in their diet and still presents with symptoms of fatty acid deficiency, carrying out a test such as Opti-O-3 may be wise.

Most importantly, fatty acid ratios can be determined by testing; dietary and supplement protocols can therefore be personalised depending on the results. The ‘omega-3 index’ is a useful tool to indicate the percentage of omega-3 in the body, and the AA:EPA ratio will help to indicate inflammatory levels. Other fatty acids including trans fats can also be identified in a fatty acid test to identify intake of unhealthy processed foods.

Supplementing with fatty acids

Pharmepa-RESTORE - CopySupplements may be necessary for some people if they are not getting enough of the right types of fats in their diet, or if they have enzyme insufficiency, etc – EPA and DHA (fish oil), GLA (evening primrose oil), ALA (echium seed oil and linseed oil), SDA (echium seed oil) and oleic acid (echium seed oil and olive oil).

As getting high doses of EPA from fish can be difficult without exceeding toxin levels such as methyl mercury, a concentrated EPA supplement may be beneficial. EPA in excess of DHA is more effective in terms of reducing inflammation.

Choosing a suitable EPA supplement depends on the source of fish, purity, concentration and dose. Smaller fish are ideal for supplementing due to their naturally low levels of contaminants, short life span and therefore sustainability. Choosing a wild source of fish over farmed is also more favourable in terms of the ratios of fatty acids. Even with small fish, small levels of contamination such as methyl mercury, PCBs and dioxins may exist, so a supplement which has been purified (e.g. by molecular distillation) to certified free levels is the safest option when looking to minimise toxin levels. Once the quality of the fish oil has been determined, for therapeutic health beneficial effects a high concentration will provide a good dose. A standard fish oil, prior to concentration is 18% EPA and 12% DHA. A highly concentrated fish oil would be 70% concentration or above.

Pharmepa RESTORE provides pure EPA derived from wild sustainably source anchovies, certified free from heavy metals, at a concentration of 90%, supplying 1000mg of the active ingredient omega-3 EPA.

Vegetarian alternative to fish oil supplements

Echiomega-3Dview (2)For vegetarians, or those unwilling to eat fish or take a fish oil supplement, there are other options. Plant-based omega-3 fatty acids can be converted to omega-3 EPA to some extent in the body. In order to optimise this conversion, a supplement containing echium seed oil, rich in omega-3 SDA is ideal. Echium seed oil alongside a supplement containing the enzyme cofactors zinc, magnesium and vitamin B6 (such as Neurobalance) will support fatty acid metabolism.

Other vegetarian sources of fatty acid supplements include linseed oil, algae and hempseed. Linseed oil is a source of ALA, a short-chain fatty acid requiring additional conversion, therefore very large doses would need to be taken to match the effects of echium seed oil. Algae is a source of omega-3 DHA, suitable during pregnancy, although not ideal on its own for the majority of individuals given its effects at down-regulating enzymes required for fatty acid metabolism. Hempseed oil also contains omega-6 fatty acids, therefore it is not as anti-inflammatory as echium seed oil.

References

(1) Bueno NB, de Melo IS, de Oliveira SL, da Rocha AT. Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials. Br J Nutr 2013 Oct;110(7):1178-87.
(2) Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin Nutr 2010 Mar;91(3):535-46.
(3) Welsh JA, Sharma A, Cunningham SA, Vos MB. Consumption of added sugars and indicators of cardiovascular disease risk among US adolescents. Circulation 2011 Jan 25;123(3):249-57.
(4) de BJ, Sauleda J, Balcells E, Gomez FP, Mendez M, Rodriguez E, et al. Association between Omega3 and Omega6 fatty acid intakes and serum inflammatory markers in COPD. J Nutr Biochem 2012 Jul;23(7):817-21.
(5) Ohnishi H, Saito Y. Eicosapentaenoic acid (EPA) reduces cardiovascular events: relationship with the EPA/arachidonic acid ratio. J Atheroscler Thromb 2013;20(12):861-77.
(6) Pottala JV, Talley JA, Churchill SW, Lynch DA, von SC, Harris WS. Red blood cell fatty acids are associated with depression in a case-control study of adolescents. Prostaglandins Leukot Essent Fatty Acids 2012 Apr;86(4-5):161-5.
(7) Conklin SM, Manuck SB, Yao JK, Flory JD, Hibbeln JR, Muldoon MF. High omega-6 and low omega-3 fatty acids are associated with depressive symptoms and neuroticism. Psychosom Med 2007 Dec;69(9):932-4.
(8) Patterson E, Wall R, Fitzgerald GF, Ross RP, Stanton C. Health implications of high dietary omega-6 polyunsaturated Fatty acids. J Nutr Metab 2012;2012:539426.
(9) Bloch MH, Qawasmi A. Omega-3 fatty acid supplementation for the treatment of children with attention-deficit/hyperactivity disorder symptomatology: systematic review and meta-analysis. J Am Acad Child Adolesc Psychiatry 2011 Oct;50(10):991-1000.
(10) Feranil AB, Duazo PL, Kuzawa CW, Adair LS. Coconut oil is associated with a beneficial lipid profile in pre-menopausal women in the Philippines. Asia Pac J Clin Nutr 2011;20(2):190-5.
(11) Mozaffarian D, Micha R, Wallace S. Effects on coronary heart disease of increasing polyunsaturated fat in place of saturated fat: a systematic review and meta-analysis of randomized controlled trials. PLoS Med 2010 Mar;7(3):e1000252.
(12) Gillingham LG, Harris-Janz S, Jones PJ. Dietary monounsaturated fatty acids are protective against metabolic syndrome and cardiovascular disease risk factors. Lipids 2011 Mar;46(3):209-28.
(13) Shin JY, Xun P, Nakamura Y, He K. Egg consumption in relation to risk of cardiovascular disease and diabetes: a systematic review and meta-analysis. Am J Clin Nutr 2013 Jul;98(1):146-59.

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Kyla Newcombe

About Kyla Newcombe

Kyla is a highly qualified clinical nutritionist with a master’s degree in Nutritional Medicine. Kyla runs her own private practice, offering personalised dietary and supplement advice. Kyla has extensive experience in weight management, skin disorders and digestive issues. Her website is at www.kylanewcombenutrition.com. Kyla regularly contributes to articles for leading consumer magazines, and blogs about healthy cake ingredients and recipes at www.healthybake.co.uk.