Omega-6s
What are Omega-6s?
Omega-6 is an essential fatty acid involved in cell membrane structure and activity, as well as brain development. [10] Due to the fact that many foods contain both omega-6 and omega-3 together, it can be challenging to associate effects of omega-6 alone in research studies. [5] Focusing on the omega-6 ratio of the diet by emphasizing alternative fat sources is key.
The two main forms of Omega 6 Fatty Acids (also denoted w-6 or n-6) include:
Linoleic Acid - LA
The predominant omega-6 in the American diet is Linoleic Acid, totalling about 6% of total energy intake. [5]
Arachidonic Acid - AA
Arachidonic Acid is formed by the conversion of LA, or from a few food sources like grain-fed animals, dairy, or eggs. [7]
Omega-6 fatty acid is a polyunsaturated fat and is considered an essential nutrient since it cannot be created in the human body. [11] When eaten in moderation and in place of saturated fats, they may be beneficial, but when consumed in large amounts they can be pro-inflammatory.
When considering omega-6 intake, omega-6 to omega-3 ratio is important to keep in mind. Typical Western diets can exceed omega-6 to omega-3 ratios of 15:1 and even 20:1. [7, 1]
The ideal omega ratio is 4:1 and under for healthy nutrient levels and prevention of adverse effects. [8]
This essentially means: focus on consuming higher levels of omega-3s, and consume fewer omega-6s
Consumption of omega-6 fatty acids may be elevated in kids, especially those with picky eating behaviors, due to the typically higher omega-6 content of processed foods.
Studies have shown that the combined reduction of omega-6 with additional intake of omega-3 fatty acids is more efficient in lowering AA levels than omega-6 reduction alone. [9,6]
Modern agri-business plays a large role in the omega-6 and omega-3 fatty acid content in our food [8]. For example, free range and enriched chicken egg yolks have a much lower omega-6 ratio than standard USDA egg yolks. [7]
Food Sources of Omega-6s
See more on oils in the Oils note.
Vegetable oils: corn, soybean
Margarine
Butter
Coconut oil
Safflower oil
Meats: beef, chicken, pork
Infant formulas
Recommended Intake
These recommendations are based on the Adequate Intake, which is the recommended average daily nutrient intake appropriate for a healthy group or population. [3]
Males
o-6 months: 4.4 g
7-12 months: 4.6 g
1-3 years: 7 g
4-8 years: 10 g
9-13 years: 12 g
14-18 years: 16 g
19-50 years: 17 g
51+ years: 14 g
Females
o-6 months: 4.4 g
7-12 months: 4.6 g
1-3 years: 7 g
4-8 years: 10 g
9-13 years: 10 g
14-18 years: 11 g
19-50 years: 12 g
51+ years: 11 g
Deficiency
Omega-6 deficiencies are typically uncommon. Deficiency symptoms include:
Scaly skin lesions
Stunted growth
Thrombocytopenia - low blood platelet levels
While rare, individuals with metabolism errors may become deficient in omega-6 due to the lack of FADS2 enzyme. [11]
Children with autism may have lower than average polyunsaturated fatty acid blood levels, specifically omega-6 Arachidonic Acid. [10]
Toxicity
While there are no direct values associated with omega-6 toxicity and no established Tolerable Upper Intake Levels (UL), it is important to focus on the overall ratio of omega-6 to omega-3 fatty acids in the diet. Western diets are typically associated with high, unwanted ratios of 15:1 which increase risk of negative health effects. [1]
Chronic Disease Risks
Obesity - Arachidonic Acid acts against weight balance processes which aids in the increasing obesity prevalence of each generation by high omega-6 consumption patterns. [7]
Insulin Resistance - High omega-6 AA levels can disrupt hunger signal balance as well as decrease insulin resistance contributing to diabetes risk. [7]
Coronary Heart Disease - Inflammation and increased plaque build up, called atherosclerosis, are associated with high omega-6 ratios. [4]
Headaches
Arachidonic Acid (a form of omega-6) can be converted into pain processing compounds in the nervous and immune system and is associated with chronic headaches. [6]
Supplements
Omega-6 supplements are not typically needed and can be easily consumed in the average diet. Oftentimes Omega-3 levels should be increased while decreasing omega-6 consumption from more processed food sources. To learn more about Omega-3 supplementation, see the omega-3s or fish oil note.
DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.
Omega-6 & Autism in the Research
Omega-6 & Inflammation
In excess amounts, omega-6 can promote inflammatory processes including allergy responses, chronic diseases, and neuro-inflammation. [9, 7]
A study in mice with omega-6 ratios of 20:1, 4:1, and 1:1 showed the lowest ratio resulted in the lowest non-HDL, or bad cholesterol, and inflammation. [4]
Omegas & Sensory Processing
One study measuring omega-3 and omega-6 supplements in toddlers with ASD born preterm showed positive (though not significant) benefits in reduction of behaviors associated with sensory processing disorder in some children. [2]
Omegas & Mood Disorders
A study on at risk individuals evaluated the relationship of the high omega-6 and low omega-3 ratio on the development of mood disorders including anxiety and depression. [1]
Elevated omega 6:3 ratios were observed with increased depression risk, but more research is needed to determine significance. [1]
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[1]Berger ME, Smesny S, Kim SW, et al. Omega-6 to omega-3 polyunsaturated fatty acid ratio and subsequent mood disorders in young people with at-risk mental states: a 7-year longitudinal study. Transl Psychiatry. 2017;7(8):e1220.
[2]Boone KM, Gracious B, Klebanoff MA, et al. Omega-3 and -6 fatty acid supplementation and sensory processing in toddlers with ASD symptomology born preterm: A randomized controlled trial. Early Hum Dev. 2017;115:64-70.
[3]Dietary Reference Intakes for Energy, Carbohydrate. Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2002/2005).
[4]Dinicolantonio JJ, O'keefe JH. Importance of maintaining a low omega-6/omega-3 ratio for reducing inflammation. Open Heart. 2018;5(2):e000946.
[5]Maki KC, Eren F, Cassens ME, Dicklin MR, Davidson MH. ω-6 Polyunsaturated Fatty Acids and Cardiometabolic Health: Current Evidence, Controversies, and Research Gaps. Adv Nutr. 2018;9(6):688-700.
[6]Ramsden CE, Mann JD, Faurot KR, et al. Low omega-6 vs. low omega-6 plus high omega-3 dietary intervention for chronic daily headache: protocol for a randomized clinical trial. Trials. 2011;12:97.
[7]Simopoulos AP. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity. Nutrients. 2016;8(3):128.
[8] Simopoulos AP. The importance of the ratio of omega-6/omega-3 essential fatty acids. Biomed Pharmacother. 2002;56(8):365-379.
[9]Taha AY, Cheon Y, Faurot KF, et al. Dietary omega-6 fatty acid lowering increases bioavailability of omega-3 polyunsaturated fatty acids in human plasma lipid pools. Prostaglandins Leukot Essent Fatty Acids. 2014;90(5):151-7.
[10]Tallima H, El Ridi R. Arachidonic acid: Physiological roles and potential health benefits - A review. J Adv Res. 2018;11:33-41.
[11]Whelan J. The health implications of changing linoleic acid intakes. Prostaglandins Leukot Essent Fat. Acids. 2008;79:165–167. doi: 10.1016/j.plefa.2008.09.013.
Authors
Sarah Reale, Dietetics Student
Brittyn Coleman, MS, RDN/LD, CLT
