In our article, THE FLEXIBILITY DIET, we discussed the importance of including foods with anti-inflammatory properties for joint health. Omega-3s are one of these crucial nutrients helping the body to reduce harmful inflammation, but not only: these substances have many other functions in our body. In this article, we summarise their functions and help you find the foods you can include to increase your intake of omega-3s. Finally, how do you know if you are getting enough? Let's find out the signs of omega-3 deficiency.

Eye close up


Several different omega-3s exist, but most scientific research publications focus on three: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). DHA is a major constituent of heart cells, sperm, brain grey matter, and the eye's retina. Several studies have shown that DHA is necessary for central nervous system functionality as well as the visual activity of infants. Additionally, these nutrients can be converted to a series of hormone-like substances that play major roles in regulating diverse bodily functions, including blood pressure, platelet aggregation, blood clotting, blood lipid profiles, immune response, the inflammation response to injury, and infections and the resolution of inflammation [6].



For adult males and non-pregnant/non-lactating adult females, 0.250 grams per day of EPA plus DHA is recommended, with insufficient evidence to set a specific minimum intake of either EPA or DHA alone; both should be consumed. The minimum intake for adult pregnant and lactating females for optimal adult health and foetal and infant development is 0.3 grams per day EPA+DHA, of which at least two-thirds (2/3) should be DHA [2].

The FDA recommends that the intake should not exceed 3 grams per day of EPA plus DHA and no more than 2 grams per day from dietary supplementation [5]. 

For ALA, the recommended daily intake levels are:

  • Men: 1.6 gram per day
  • Women: 1.1 gram per day
  • Pregnant women: 1.4 gram per day
  • Breastfeeding women: 1.3 gram per day


ALA occurs in almost all dietary fats and reaches significant proportions in most vegetable oils. ALA is primarily present in plants, occurring in high concentrations in some seeds, nuts, and vegetable oils. The following vegetable seed oils are listed from highest to lowest omega-3 content: linseed oil, flaxseed oil, pumpkin seed oil, canola oil, soybean oil, safflower oil and sunflower oil [9].

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most important omega-3 fatty acids in human nutrition. EPA and DHA are components of marine fats. Fish such as mackerel, salmon, sardine, herring and smelt are excellent sources of EPA and DHA [2].

Skin and nails


Skin and hair: A deficiency of essential fatty acids—omega-3s or omega-6s—can cause rough, scaly skin and brittle nails [7]. Hair changes include loss of scalp hair and eyebrows and lightening of hair [3].

Visual sensitivity: Omega-3 fatty acids have been linked with visual impairment symptoms such as light sensitivity, itching or burning, sandy or gritty sensation, redness, blurred vision, ocular fatigue or excessive blinking. Consistent evidence suggests that omega-3s may act in a protective role against ischemia-, light-, oxygen-, inflammatory-, and age-associated pathology of the vascular and neural retina [1,8].

Mood disorders: Dietary deficiencies of omega-3s are associated with a higher risk of developing psychiatric disorders, such as depression, bipolar disorder, schizophrenia, dementia, attention-deficit or hyperactivity disorder, and autism. Thus, changes in your mood or other behavioural issues could be pointing to a deficiency of omega-3 [4,7].

Joint stiffness and pain: Clinical researchers have demonstrated that omega-3s may positively affect the treatment of swollen and tender joints; hence, it's been suggested that joint stiffness and pain may be present due to low intake of omega-3.  The anti-inflammatory and pain-relieving properties of omega-3s may be due to their ability to inhibit the production of cytokines, which are small secreted proteins released by cells that specifically affect the interactions and communications between cells. Some cytokines are involved in injury-induced inflammation and pain development; omega-3s inhibit the production of these inflammatory substances [9,10].

Excessive thirst and frequent urination have been attributed as classic symptoms of essential fatty acid deficiencies [7]

Water and thirst


Many factors could contribute to developing the symptoms described in this article; however, if you have more than one and know that your diet contains limited omega-3 source food intake, it might be wise to supplement. We advise including food sources as a first approach to increasing your omega-3 intake and looking for professional guidance before you start supplementing. Your health provider will most likely evaluate your biochemical profile with blood tests and determine if your omega-3 levels are adequate.

 [1] Bhargava R, Kumar P, Kumar M, Mehra N, Mishra A.(2013). A randomized controlled trial of omega-3 fatty acids in dry eye syndrome. Int J Ophthalmol, 18;6(6), pp. 811-6. doi: 10.3980/j.issn.2222-3959.2013.06.13.
[2] Food and Agriculture Organization of the United Nations. (2010). Fats and fatty acids in human nutrition. Report of an expert consultation. FAO Food and Nutrition Paper, 91, pp. 1-166.
 [3] Guo EL, Katta R. (2017). Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatol Pract Concept, 31;7(1), pp. 1-10. doi: 10.5826/dpc.0701a01. 
 [4] Lange, K. W. (2020). Omega-3 fatty acids and mental health. Global Health Journal, 4(1), pp. 18-30.
 [5] National Institutes of Health. (2019). Omega-3 fatty acids–fact sheet for health professionals. Retrieved from
 [6] Ponnampalam EN, Sinclair AJ, Holman BWB. (2021).The Sources, Synthesis and Biological Actions of Omega-3 and Omega-6 Fatty Acids in Red Meat: An Overview. Foods, 10(6):1358. doi: 10.3390/foods10061358.
 [7] Richardson, A. J. (2003). The importance of omega-3 fatty acids for behaviour, cognition and mood. Scandinavian Journal of Nutrition, 47(2),pp. 92-98.
 [8] SanGiovanni, J. P. and Chew, E. Y. (2005). The role of omega-3 long-chain polyunsaturated fatty acids in health and disease of the retina. Progress in retinal and eye research, 24(1), 87-138.
 [9] Yashodhara, B. M., Umakanth, S., Pappachan, J. M., Bhat, S. K., Kamath, R. and Choo, B. H. (2009). Omega-3 fatty acids: a comprehensive review of their role in health and disease. Postgraduate Medical Journal, 85(1000), pp. 84–90. doi:10.1136/pgmj.2008.073338
 [10] Zhang JM, An J. (2007) Cytokines, inflammation, and pain. Int Anesthesiol Clin,45(2), pp. 27-37. doi: 10.1097/AIA.0b013e318034194e.

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