Abstract: Omega-3 fatty acids have become one of the most studied and recommended nutrients by the global medical community. And for good reason: scientific evidence accumulated over recent decades shows that regular consumption of omega-3 from fish has positive effects...
Omega-3 from Fish: Why Everyone is Talking About These Fatty Acids
Omega-3 fatty acids have become one of the most studied and recommended nutrients by the global medical community. And for good reason: scientific evidence accumulated over recent decades shows that regular consumption of omega-3 from fish has measurable positive effects on cardiovascular, brain, and inflammatory health.
But amidst all the supplements, marketing, and misinformation, what does science really say? What are the best sources of omega-3? Is fresh fish or canned fish better? At Mercat del Ninot in Barcelona, where we have been working with the best seafood products since 1990, we address these questions with data and experience.
What is Omega-3: The Three Important Types
When we talk about omega-3, we are actually referring to a family of polyunsaturated fatty acids. The three most important for health are:
| Type | Full Name | Main Source | Key Function |
|---|---|---|---|
| EPA | Eicosapentaenoic Acid | Oily fish | Anti-inflammatory, cardiovascular health |
| DHA | Docosahexaenoic Acid | Oily fish | Brain development, cognitive function, eye health |
| ALA | Alpha-Linolenic Acid | Flax seeds, walnuts, chia | Precursor to EPA and DHA (very low conversion: 5-10%) |
The distinction is crucial: EPA and DHA are the omega-3s with proven benefits and are obtained almost exclusively from fish and seafood. ALA from plant sources has an extremely low conversion rate to EPA and DHA (between 5% and 10%), meaning you would need to consume enormous quantities of seeds to get the equivalent of one serving of sardines.
That's why, when nutritionists recommend omega-3, they are fundamentally talking about eating fish.
Cardiovascular Benefits of Omega-3
The strongest research on omega-3 focuses on cardiovascular health. Proven benefits include:
Triglyceride Reduction
Regular consumption of EPA and DHA reduces blood triglyceride levels by 15% to 30%, according to multiple meta-analyses. This effect is so significant that there are concentrated omega-3 drugs specifically prescribed for hypertriglyceridemia.
Anti-inflammatory Effect
EPA omega-3s reduce the production of pro-inflammatory molecules (prostaglandins, leukotrienes) and increase the production of resolvins and protectins, which actively resolve inflammation. Chronic low-grade inflammation is linked to atherosclerosis, cancer, and neurodegenerative diseases.
Heart Rhythm Regulation
DHA is incorporated into the membranes of heart cells, helping to stabilize their electrical activity. Various studies have shown an association between fish consumption and a lower risk of arrhythmias.
Improved Lipid Profile
In addition to reducing triglycerides, omega-3s can slightly increase HDL cholesterol (the so-called good cholesterol) and modify the size of LDL particles towards a less atherogenic profile.
Other Science-Backed Benefits
- Brain health: DHA constitutes 40% of the fatty acids in the brain. Its adequate consumption is associated with less age-related cognitive decline.
- Eye health: DHA is a structural component of the retina. Its deficiency is associated with a higher risk of macular degeneration.
- Pregnancy: DHA is essential for fetal brain and visual development, especially in the third trimester.
- Joint health: EPA has anti-inflammatory properties that can alleviate symptoms of rheumatoid arthritis.
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Ranking of Fish with the Most Omega-3
Not all fish provide the same amount of omega-3. Oily fish are clearly superior to white fish (lean). Here is the ranking by EPA+DHA content per 100g edible portion:
| Fish | EPA+DHA (mg/100g) | Category | Availability |
|---|---|---|---|
| Mackerel | 2,600 | Oily | Year-round |
| Atlantic salmon | 2,200 | Oily | Year-round |
| Sardine | 1,800 | Oily | May-Oct (optimal) |
| Herring | 1,700 | Oily | Year-round |
| Anchovy | 1,500 | Oily | Spring-summer |
| Bonito del norte | 1,300 | Oily | Jun-Oct |
| Bluefin tuna | 1,200 | Oily | May-Jul |
| Trout | 900 | Semi-oily | Year-round |
| Sea bass | 600 | Semi-oily | Year-round |
| Cod | 200 | White | Year-round |
| Hake | 150 | White | Year-round |
The great omega-3 champions are mackerel, salmon, and sardines. With just one can of quality sardines like our Dardo sardines in olive oil, you get practically the recommended daily dose of omega-3.
How Much Omega-3 Should You Consume Daily?
Recommendations vary by institution, but there is broad consensus:
- General population: 250-500 mg of EPA+DHA per day (equivalent to 2-3 servings of oily fish per week)
- People with cardiovascular risk: 1,000 mg of EPA+DHA per day (according to the American Heart Association)
- Pregnant or breastfeeding women: minimum 200 mg of DHA per day (EFSA recommendation)
- Hypertriglyceridemia: 2,000-4,000 mg per day (under medical supervision)
For most people, eating oily fish 2-3 times a week is enough to reach these levels without the need for supplements.
In practice: how to reach the dose with real food
- 1 can of sardines in oil (120 g) = ~2,100 mg of EPA+DHA
- 1 serving of salmon (150 g) = ~3,300 mg of EPA+DHA
- 1 can of anchovies (50 g) = ~750 mg of EPA+DHA
- 1 serving of bonito (150 g) = ~1,950 mg of EPA+DHA
With one can of sardines a day or a serving of salmon every two days, most people would amply cover their omega-3 needs.
Canned vs. Fresh Fish: Is Omega-3 Lost?
One of the questions we get asked most often at Mercat del Ninot: do canned fish retain omega-3? The answer, backed by scientific studies, is clear:
Canned fish retains almost all of its omega-3 content.
The canning process (heat sterilization) minimally alters omega-3 fatty acids because they are relatively heat-stable, especially when protected by the covering oil. Several studies have shown that:
- Canned sardines retain between 85% and 95% of their original EPA+DHA content
- Olive oil used as a covering protects omega-3s from oxidation during storage
- Canned fish in olive oil are superior to canned fish in water for omega-3 preservation
This makes quality canned goods one of the most practical and economical sources of omega-3. Our sardines in olive oil, our Norwegian smoked salmon, and our Cantabrian anchovies are excellent sources of omega-3 that you can always keep in your pantry.
Advantages of canned goods as an omega-3 source
| Factor | Fresh fish | Canned in olive oil |
|---|---|---|
| Omega-3 content | 100% (reference) | 85-95% |
| Availability | Depends on market and season | Always available in pantry |
| Preparation | Requires cooking | Ready to eat |
| Shelf life | 2-3 days in fridge | 2-5 years unopened |
| Price per mg of omega-3 | Variable, generally higher | Generally more economical |
| Additional calcium | Only if you eat the bones | Soft edible bones (sardines) |
Omega-3 and Supplements: Are They Necessary?
With the supplement industry generating billions from fish oil capsules, it's worth asking: do you need supplements if you eat fish regularly?
The latest scientific evidence suggests that:
- If you eat 2-3 servings of oily fish per week, you do not need omega-3 supplements. Your diet covers your needs.
- If you don't eat fish (due to allergy, a vegan diet, or simply because you don't like it), supplements can be a reasonable alternative, although the evidence for their benefits is less consistent than for direct fish consumption.
- Fish provides more than omega-3: high-quality protein, vitamin D, selenium, iodine, zinc. A supplement only provides isolated omega-3.
- Bioavailability is higher in fish: omega-3 from fish is absorbed better than from capsules, possibly due to the food matrix that accompanies it.
The conclusion of the Spanish Society of Cardiology is clear: the first recommendation is always to consume fish. Supplements are a second option for people who cannot or do not want to eat fish.
At Bacalalo, we believe the best way to incorporate omega-3 into your diet is by enjoying good seafood products. From our premium sardines to our Norwegian smoked salmon or our Cantabrian anchovies, each product is a delicious and natural source of essential fatty acids. Because taking care of your health and enjoying gastronomy are not incompatible.
Frequently Asked Questions
Which fish has the most omega-3?
Mackerel has the highest omega-3 content, with about 2,600 mg of EPA+DHA per 100g. It is followed by Atlantic salmon (2,200 mg), sardines (1,800 mg), herring (1,700 mg), and anchovies (1,500 mg). All are oily fish.
How many times a week should you eat fish to get enough omega-3?
The general recommendation is to consume oily fish (sardines, salmon, mackerel, anchovies) 2-3 times a week. This provides between 250 and 500 mg daily of EPA+DHA, the recommended amount for the general population according to organizations like EFSA and WHO.
Do canned fish retain omega-3?
Yes, canned fish in olive oil retains between 85% and 95% of the original omega-3 content. Olive oil protects fatty acids from oxidation during storage. Canned fish is one of the most practical and economical sources of omega-3.
Is omega-3 from fish the same as from flax or chia seeds?
No. Fish provides EPA and DHA, the omega-3s with proven benefits. Flax and chia seeds provide ALA, a precursor that the body converts to EPA and DHA with very low efficiency (only 5-10%). For real omega-3 benefits, fish is clearly superior.
Do I need to take omega-3 supplements if I eat fish?
If you eat 2-3 servings of oily fish per week, you generally do not need supplements. Fish provides omega-3 with better bioavailability and also provides protein, vitamin D, selenium, and iodine. Supplements are an alternative for people who cannot or do not want to consume fish.
How much omega-3 does a can of sardines have?
A standard can of sardines in olive oil (120 g net content) provides approximately 2,100 mg of EPA+DHA. This amply covers the recommended daily dose of 250-500 mg for the general population, making canned sardines one of the most efficient sources of omega-3.
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Conclusion
At Mercat del Ninot in Barcelona, we have been selecting the best seafood products for over 35 years. If this guide has been useful to you, explore our catalog at bacalalo.com and receive the same quality we sell at the market since 1990 at home.
