Omega-3, Total

Total omega-3 measures the amount of long-chain omega-3 fats in your blood, usually reported as the sum of EPA, DPA, and DHA as a percentage of all measured fatty acids. Many labs assess this in the plasma phospholipid fraction or whole blood. It tracks how much omega-3 you are regularly getting from fish, seafood, or supplements, and it correlates closely with the red-blood-cell “Omega-3 Index.” Higher percentages generally reflect better long-term intake and tissue status.

Omega-3 fats are building blocks for cell membranes in the heart, brain, eyes, and immune system. People with higher circulating omega-3 levels tend to live longer, with large pooled cohort data linking higher blood omega-3s to lower risk of death from all causes over many years. Total omega-3 is therefore a practical marker to monitor across time as you build sustainable habits. (3)

Labs that report “total omega-3” (EPA+DPA+DHA) provide risk bands tied to cardiovascular outcomes. These total omega-3 values also line up strongly with the Omega-3 Index used in research, so improving one typically improves the other.

Small, steady changes move this marker in weeks and compound over time.

• Eat oily fish 2–3 times per week. Trials using about three meals of salmon or tuna per week increased the Omega-3 Index by roughly +1.7 percentage points in 8 weeks, with some participants moving into a low-risk range. Body fat patterning and your starting level influence how much you rise, so consistency matters. (2)

• Take omega-3 with meals that include some fat. Absorption of omega-3 is significantly higher when taken after a meal versus fasting, so pair supplements with a main meal that contains healthy fats (for example, olive oil or avocado). (4)

• Lower excess omega-6 linoleic acid (LA) to help omega-3 “compete.” Short trials show that reducing LA (for example, swapping high-LA seed oils like sunflower or standard soybean for extra-virgin olive oil or high-oleic versions) raised plasma long-chain omega-3 percentages within 4 weeks even without adding fish oil. Practical swaps: choose olive oil for most cooking, pick canned fish packed in olive oil or water, and limit frequent deep-fried foods. (5)

• Plant-based? Use algal DHA/EPA. Algal oil directly supplies DHA (and sometimes EPA) and raises blood omega-3 levels in vegetarians and vegans. Pair it with the meal strategy above and the LA swap for a bigger lift over time.

• Optimal (lower risk): ≥ 5.5%

• Borderline: 3.8% to 5.4%

• Low: ≤ 3.7%

1. Quest Diagnostics. OmegaCheck Test Summary. Quest Diagnostics, 2025. Available from: https://testdirectory.questdiagnostics.com/test/test-guides/TS_OmegaCheck/omegacheck

2. Richardson KR, et al. The Omega-3 Index Response to an 8-Week Randomized Intervention Containing Three Fatty Fish Meals per Week Is Influenced by Adiposity in Overweight to Obese Women. Frontiers in Nutrition, 2022. Available from: https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2022.810003/pdf

3. Harris WS, Tintle NL, Imamura F, et al. Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies. Nature Communications, 2021. Available from: https://www.nature.com/articles/s41467-021-22370-2.pdf

4. Shiramoto M, et al. Effects of Food on the Pharmacokinetics of Omega-3-Carboxylic Acids in Healthy Japanese Male Subjects. Journal of Atherosclerosis and Thrombosis, 2017. Available from: https://www.jstage.jst.go.jp/article/jat/24/9/24_38737/_pdf/-char/en

5. Wood KE, et al. A low omega-6 polyunsaturated fatty acid diet increases omega-3 long-chain PUFA status in plasma phospholipids in humans. Prostaglandins, Leukotrienes and Essential Fatty Acids, 2014. Available from: https://researchnow.flinders.edu.au/en/publications/a-low-omega-6-polyunsaturated-fatty-acid-n-6-pufa-diet-increases-