Fatty acid
Omega-3 fatty acids
This article is written from cited public sources but has not yet been signed off by a qualified expert. Use it as general background only, and check important details with a health professional.
Omega-3s are healthy fats. ALA comes from seeds, nuts and some oils; EPA and DHA come mainly from fish. Eating fish as part of a balanced diet supports heart health. Fish-oil supplements lower triglycerides but do not suit everyone and can interact with blood thinners.
What is Omega-3 fatty acids?
Omega-3s are polyunsaturated fats. The three main ones are ALA (alpha-linolenic acid), found in plant foods, and EPA and DHA, found mainly in fish and seafood.[1]
ALA is essential: the body cannot make it, so it must come from food. The body can turn a small amount of ALA into EPA and DHA, but very little (reported at under 15%).[1]
Its role in the body
Important food sources
- Flaxseed (alsi), chia seeds and walnutsPlant sources of ALA.
- Soybean and canola oilsPlant oils containing ALA.
- Fatty fish such as sardines (mathi/chaala), mackerel (bangda/ayala) and salmonMain sources of EPA and DHA.
- Other fish and seafoodProvide smaller amounts of EPA and DHA.
- Algal oil supplementsA vegetarian source of DHA (and sometimes EPA).
- Nuts and oilseeds as part of a varied dietICMR-NIN advises adequate nuts and oilseeds to meet essential fatty acid needs.
Recommended dietary intake
| Group | Amount | Basis | Region |
|---|---|---|---|
| Adults (Indian guidance)ICMR-NIN 2020 brief note: about 2.2 g n-3 PUFA (and 6.6 g n-6 PUFA) for essential functions, from nuts, oilseeds and diverse foods. | 2.2 g/day of n-3 PUFA[2] | GUIDELINE | India |
| Men 14+ years (as ALA) | 1.6 g/day[1] | AI | USA |
| Women 14+ years (as ALA) | 1.1 g/day[1] | AI | USA |
| Pregnancy (as ALA) | 1.4 g/day[1] | AI | USA |
| Breastfeeding (as ALA) | 1.3 g/day[1] | AI | USA |
Signs sometimes associated with low levels
Why symptoms alone cannot confirm a deficiency
Signs like tiredness, weakness, hair fall or low mood are very common and have many possible causes, such as poor sleep, stress, infections, thyroid problems or other illnesses.
The same sign can come from several different nutrients, or from no nutrient problem at all.
Only a qualified clinician, using your history, an examination and, when needed, lab tests, can say whether a deficiency is present. This app cannot diagnose a deficiency from symptoms or from BMI.
Dry skin is common and has many causes; it is rarely due to low omega-3 intake.
Tests a clinician might consider
- Omega-3 status can be estimated from fatty acids in red blood cells (sometimes reported as an "omega-3 index"), but no cut-off has been agreed below which health is harmed. These tests are mostly used in research.[1]
Who is more likely to have low intake
- Classic deficiency is very rare. People who eat little or no fish, such as many vegetarians, have low EPA and DHA intakes; whether this harms health is not established.[1]
Potential benefits and quality of evidence
- Eating fish and other seafood as part of a balanced diet supports heart health, especially when it replaces less healthy foods.[1] Moderate evidence
- Fish oil and other EPA/DHA supplements lower blood triglycerides.[1] Established
- Supplements might lower some heart-disease outcomes, with stronger evidence in people with existing heart disease than in healthy people; large trials have mixed results.[1] Limited evidence
- Enough DHA in pregnancy is important for the baby’s growth, brain and eyes; eating seafood in pregnancy is linked with better child development.[1] Moderate evidence
- Evidence that omega-3 supplements prevent cancer, dementia, dry eye or depression is inconsistent or weak.[1] Not enough evidence
Side effects
- Usually mild: unpleasant taste, bad breath, heartburn, nausea, stomach discomfort, diarrhoea, headache and smelly sweat.[1]
Risks of too much
Medicine and supplement interactions
- Warfarin and other anticoagulants: Fish oil has antiplatelet effects at high doses and might prolong clotting time (INR). Most research suggests modest doses do not significantly change warfarin control, but INR monitoring is advised when combining them.[1]
Never start, stop or change a prescribed medicine because of this list — talk to your doctor or pharmacist.
Pregnancy and breastfeeding
- DHA is important in pregnancy. Seafood choices lower in mercury (such as sardines and salmon) are preferred. Some expert groups suggest extra DHA in pregnancy; whether a supplement is needed should be decided with the antenatal care team.[1]
Kidney and liver cautions
- No specific kidney or liver upper limits are set for omega-3s. People with liver or kidney disease, and anyone on blood thinners, should check with their doctor before taking concentrated omega-3 supplements.[1]
Upper intake limits
The US Food and Nutrition Board did not set a UL for omega-3s. The European Food Safety Authority and US FDA have judged combined EPA+DHA intakes up to about 5 g/day from supplements to be safe for adults; this is a safety judgement, not a recommended intake.[1]
When to talk to a professional
Talk to a doctor or registered dietitian before starting a supplement, especially if you are pregnant or breastfeeding, have a long-term illness, or take any regular medicines.
Do not start, stop or change a prescribed medicine because of anything you read here.
Supplements sold without a prescription are not automatically safe. Doses, quality and interactions still matter.
Seek medical care promptly if you have severe, sudden or worsening symptoms.
If you take a blood thinner, have a heart-rhythm problem, or are due for surgery, talk to your doctor before taking fish oil.
Prescription omega-3 medicines for high triglycerides are a medical treatment decided by a doctor.
Still being verified
- Omega-3 content of Indian fish species (e.g., Indian oil sardine, Indian mackerel) not yet verified from a licensed source.
References
- NIH Office of Dietary Supplements. Omega-3 Fatty Acids — Fact Sheet for Health Professionals (opens in a new tab) (2025-08-22). Accessed 9 Oct 2026.
- ICMR-National Institute of Nutrition (India). A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR), ICMR-NIN, 2020 (opens in a new tab). Accessed 9 Oct 2026.
Sources checked: 9 Oct 2026
This page is general education, not personal medical advice. For diagnosis, treatment or medicines, please talk to a qualified doctor, registered dietitian or pharmacist. Read our medical & AI disclaimer.