OMEGA-3 AND BENEFITS IN DIABETES

We have all heard of omega-3 and that it is healthy for us. But why? How does it benefit our health? Here I hope to shed some light on why it is so important to include this fat in your diet1. Omega-3 fatty acids are known to have multiple health benefits. The human body is unable to make this essential fatty acid2, making it important for us to get it daily from our diet. There are three types of omega-3s: Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), and Alpha-linolenic acid (ALA), which is converted by the body into EPA and DHA1. Research suggests only a small amount can be made in the body with only 2-10 % of ALA being converted EPA & DHA3. Although all forms of omega-3 have benefits, Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) have been well-researched and proven to provide the health benefits we associate with omega-3. These forms are the most biologically potent, being building blocks to many different molecules that play important roles in the functioning of various different systems within the body3. EPA and DHA are taken into many parts of the body, including cell membranes where they play a role in anti-inflammatory processes, as well as the fluidity of cell membranes3.Low intakes of dietary EPA and DHA has been linked to increased inflammatory processes, poor fetal development, general cardiovascular health and risk of the development of Alzheimer’s disease3. WHAT DOES THE RESEARCH SAY? General benefits1 Omega-3 is important across all stages of life, and it is essential for healthy aging3.A recent study found that insufficient intake of omega-3 may increase the risk of all-cause mortality4. Brain function1 Omega-3 is a key and essential structural component of the brain, where DHA is found in abundance3,4. It supports all areas of brain function, including brain development, attention and learning, cognitive health, memory support, and reduces symptoms of depression. A number of studies support the following findings:
  • A decreased risk of cognitive impairment is achieved through intake of omega-3 from fish sources. There is an association between DHA (derived from fish) intake and a reduced risk of dementia and Alzheimer’s disease4.
  • In older adults with mild memory complaints, the intake of DHA or a combination of DHA and EPA contributes to support memory health4.
  • Omega-3 supplementation may be beneficial alongside antidepressant medications in people with Major Depressive Disorder4.
Vision1 DHA is a key component of all cell membranes, and is found in particular abundance in the retina of the eye3. Intake of DHA in particular helps to prevent various vision-related health issues and maintain good vision. Those living with diabetes are at increased risk for diabetic retinopathy5. Managing your blood glucose levels as well as ensuring you are getting enough DHA will go a long way to help protect your eye health. Heart disease1 EPA and DHA have anti-inflammatory effects and play a role in preventing oxidative stress. They also lower blood pressure and lipids, improve the stability of plaque, reduce blood vessel lining dysfunction and improve blood vessel permeability. These aspects act together to decrease the risk of a cardiovascular event occurring3,4.In the 2017 America Heart Association (AHA) advisory paper on omega-3 (fish oil),authors recommend the use of omega-3 supplementation in those with diagnosed Coronary Heart Disease (CHD) such as Myocardial Infarction (MI). In patients who are at high risk for Cardiovascular Disease (CVD), authors weren’t able to come to a conclusion, with the majority of co-authors concluding that treatment is not indicated6. However a number of co-authors notedtreatment with omega-3 supplements is reasonable and can be considered in consultation with a physician, given that there is no risk associated with taking it6. Diabetes In diabetes, especially type 2, there is an increased risk of inflammation as excess body fat, especially in the abdomen causes chronic, low levels of abnormal inflammation that alter insulin's action and contributes to the disease7. Those living with diabetes are also more likely to develop heart disease, as high blood glucose levels can damage your blood vessels and nerves that control your heart and surrounding blood vessels5. Diabetics are also more likely to have certain conditions, or risk factors, that increase the chances of having heart disease or stroke, such as high blood pressure or cholesterol8. Scientific evidence suggests that there are no long-term negative effects of fish oil intake in people with diabetes, including no changes in A1C levels9.In the AHA(2017) advisory paper on omega-3 (fish oil), authors stated that available evidence from randomised control trials (RCT)does not support the use of omega-3 PUFA supplements in the general population who are not at high risk of CVD, including those with diabetes mellitus and prediabetes6.Now before you jump to conclusions it is important to note that many of the RCT were conducted in other countries such as Japan and Europe where there is a high baseline intake of dietary EPA and DHA from fish. However in South Africa where most of the population have limited access to fish and omega-3 supplements due to affordability, our baseline levels of EPA and DHA would be low. Therefore in South Africa the intake of omega-3 from EPA, DHA and ALA is recommended. How much omega 3 should we have? Typical recommendations for omega-3 fatty acids vary according to age, gender and health condition. For the general population it is recommended that you take in 250-500 mg of EPA and DHA per day10. For individuals with heart disease 1000 mg of EPA and DHA is recommended6,10. In terms of food the AHA, Heart and Stroke Foundation of South Africa (HSF)11 and the South Africa Food Based Dietary Guidelines (FBDG)12 recommend2 servings of fish per week, particularly fatty fish (e.g. sardines, pilchards, mackerel and salmon) as well as the use of liquid vegetable oils and other foods containing ALA6. Sources of ALA include chia seeds, walnuts, canola oil, flaxseeds, tofu, spinach, wheat and oat germ1.For those who don’t eat fish, have limited access to fish or are worried about exposure to contaminants, a fish oil supplement may need to be considered. Most common fish oil capsules today provide 180 mg of EPA and 120 mg DHA per capsule therefore it is important that consumers read the nutritional label to determine EPA and DHA levels in the capsule. CONCLUSION So now you know about all the health benefits associated with omega-3 intake and diabetes and associated conditions. Remember marine sources of omega-3 (EPA and DHA) are better used by our body, so aim to eat at least 2 portions of fatty fish per week. If this isn’t possible consider supplementing as well as include your plant sources of ALA. Chat to your registered dietitian or doctor if you have any questions about omega-3. REFERENCES
  1. Adapted from Benefits of Omega 3 – Written by Nicola Wilkinson FUTURELIFE Dietitian
  2. Kathleen Mahan, Sylvia Escott-Stump and Janice L. Raymond. Krause's Food and the Nutrition Care Process. St. Louis : Elsevier Saunders, 2012.(Accessed November 2018)
  3. Advances in Nutrition (2012).Omega-3 Fatty Acids EPA and DHA: Health Benefits Throughout Life. Available at: https://pdfs.semanticscholar.org/20ef/5b7cd6cfb4668cf066eeb8de5671a3a8747d.pdf(Accessed 29th January 2018)
  4. DSM (2016). Benefits of optimal omega-3 intake and status. Available at: http://www.dsm.com/content/dam/dsm/foodandbeverages/en_US/documents/hnh/benefits-of-optimal-omega-3-intake-and-status.pdf(Accessed November 2018)
  5. Healthline (2016). Diabetes and Blurry Vision: What You Need to Know. Available at: https://www.healthline.com/health/diabetes/blurry-vision#1 (Accessed 29th January 2018)
  6. Circulation (2017). Omega-3 Polyunsaturated Fatty Acid (Fish Oil) Supplementation and the Prevention of Clinical Cardiovascular Disease: A Science Advisory From the American Heart Association. Available at: http://circ.ahajournals.org/content/early/2017/03/13/CIR.0000000000000482(Accessed 29th January 2018)
  7. (2017) Diabetes and Inflammation. Available at: https://www.webmd.com/diabetes/type-2-diabetes-guide/inflammation-and-diabetes#1Text (Accessed 29th January 2018)
  8. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) (2017). Diabetes, Heart Disease, and Stroke. Available at: https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/heart-disease-stroke (Accessed 29th January 2018)
  9. Diabetesforecast (2010). Can Omega-3 Supplements Trigger Diabetes? Available at: http://www.diabetesforecast.org/2010/oct/can-omega-3-supplements-trigger-diabetes.html(Accessed 29th January 2018)
  10. Healthline (2017). How Much Omega-3 Should You Take Per Day? Available at: https://www.healthline.com/nutrition/how-much-omega-3 (Accessed 29th January 2018)
  11. Heart and Stroke Foundation of South Africa (2017). Healthy Eating. Available at: http://www.heartfoundation.co.za/healthy-eating/(Accessed 29th January 2018)
  12. South African Food based dietary Guidelines (2013). Available at: http://www.adsa.org.za/Portals/14/Documents/FoodBasedDietaryGuidelinesforSouthAfrica.pdf (Accessed 29th January 2018)