Omega-3 fatty acids are essential for our health: they support our heart, brain and even our mood. Although fish is the best known source, krill - a small marine crustacean - is gaining ground as a powerful and sustainable alternative. But not all fish and fish supplements are equal: some are contaminated and may do more harm than good. In this article, we explore krill and other fish as sources of omega-3s, the benefits of their supplements, and which options you should avoid because of their toxic load.

Krill: A star source of omega-3
  Krill, those tiny ocean dwellers, is one of the purest and most efficient sources of omega-3s (EPA and DHA). Why does it stand out so much?

1. Bioavailability: The omega-3s in krill are bound to phospholipids, which makes them easier to absorb compared to the triglycerides in many fish oils.
2. Extra antioxidants: Contains astaxanthin, a powerful antioxidant that protects cells and gives the oil its characteristic reddish colour.
3. Sustainability: Krill is found in enormous quantities in cold waters such as the Antarctic, and its fishing, when regulated, has a lower environmental impact than that of some large fish.
   A krill oil supplement may be ideal if you are looking for high quality omega-3s with less risk of contaminants, something not always guaranteed by other fish.

Fish rich in omega-3
In addition to krill, several fish are excellent natural sources of omega-3s. Here are some of the best:

1. Salmon (wild): Rich in DHA and EPA, especially if wild-caught.
2. Sardines: Small but mighty, they also provide vitamin D and calcium if you eat them with bones.
3. Mackerel: Another affordable option and loaded with omega-3s, ideal canned or fresh.
4. Anchovies: Perfect for adding flavour and nutrients to your dishes.
5. Trout: Especially freshwater trout is a clean and tasty source.
   These fish are low in the food chain, which reduces your exposure to contaminants, and are safe choices for regular consumption (2-3 times per week, according to the WHO).

Omega-3 supplements: Are they worth it?
   If you don't eat fish often, omega-3 supplements are a practical alternative. There are two main types:

1. Krill oil: As mentioned, it is more bioavailable and usually comes in small, easy-to-take capsules. Studies suggest that doses of 500-1000 mg per day can lower triglycerides and improve cardiovascular health.
2. Fish oil: Extracted from species such as sardines, mackerel or salmon, it is more common and cheaper. Look for brands that guarantee purity and are free of heavy metals (such as those certified by IFOS).

  Both offer benefits such as reducing inflammation, supporting memory and protecting the heart, but krill may be a better choice if you are concerned about oxidation or contaminants.

Contaminated fish you should avoid
Not all fish are safe, especially larger fish or those that live longer, as they accumulate toxins such as mercury, PCBs (polychlorinated biphenyls) and dioxins. These contaminants carry over into their oils, making some supplements risky. Here are the ones you should avoid eating or supplementing with:

1. Tuna (especially bluefin): High in mercury, especially in large fish.
2. Swordfish: Rich in omega-3, but its level of mercury makes it inadvisable, especially for pregnant women or children.
3. Shark: Highly contaminated by heavy metals and unsustainable.
4. Kingfish (king mackerel): Frequent in warm waters, it accumulates toxins easily.
5. Grouper: Another large fish with worrying levels of mercury.
   

   Supplements derived from these fish, if not properly purified, can concentrate these contaminants, affecting the liver, nervous system and even increasing the risk of chronic disease over time.

How to choose wisely?
   To consume: Opt for small, wild fish such as sardines, mackerel or anchovies, and limit larger fish to once a month (or avoid altogether if you are in a vulnerable group).
For supplements: Look for products with quality seals (IFOS, Friend of the Sea), indicating purification and low toxic concentrations. Krill is often a safer bet because of its low position in the food chain.

Conclusion
Krill and fish such as salmon and sardines are fantastic sources of omega-3s, with benefits ranging from a healthier heart to a clearer mind. Supplements based on them can fill the gap if your diet doesn't include them, but they're not all the same: avoid contaminated fish such as bluefin tuna or swordfish, whether on your plate or in capsules. Choosing carefully ensures you get the best of the ocean without the hidden risks. Have you tried the power of krill or do you prefer a nice sardine fillet? Your body will thank you!

Best regards,

Tribu Naturals