Omega-3 comes up often in conversations about health, but it is not always clear what it is or whether you need it at all. Let’s break it down in simple terms.
What Is Omega-3
Omega-3 is a special kind of healthy fat. Our body can hardly make it on its own, so it has to come from food. That is why it is called “essential.”
Omega-3 comes in three main types:
- Two “fish” types — found in fatty fish and seafood. For health, these are the most important and most active forms.
- One “plant” type — found in flaxseed, chia seeds, walnuts and rapeseed oil. The body can convert it into the “fish” forms, but does so poorly: only a small share is converted.
Where does fish get it? Fish hardly make it themselves. They build it up by eating algae and plankton, which are the original source.
Why It Is Good for You
It lowers blood fat. This is the most reliable and best-proven effect. At high doses (roughly 2–4 grams a day), omega-3 noticeably reduces the amount of fat in the blood.
It supports the heart and blood vessels. People who regularly eat fatty fish (about twice a week) are less likely to suffer from heart disease.
It is needed for the brain and eyesight. One of the “fish” forms is part of brain and eye cells. It is especially important for a baby during pregnancy and breastfeeding, which is why expectant and nursing mothers are usually advised to make sure they get enough omega-3.
It helps with inflammation. In rheumatoid arthritis, for example, omega-3 eases symptoms slightly, but the effect is moderate.
What is still being studied. Scientists are looking at the effect of omega-3 on mood, memory in old age, dry eyes and skin condition. The results so far are contradictory, so no miracles should be promised here.
What Is “Blood Fat” and Why Does It Matter
There is fat both in our food and in our body. The fat under the skin and around the organs is a store of this kind of fat, in other words, our main energy reserve. A gram of fat gives roughly twice as much energy as a gram of protein or carbohydrates.
After a meal, fats are broken down, then put back together and carried around by the blood. In addition, the liver turns excess calories into fat, especially calories from sugar and alcohol. That is why the level of fat in the blood reflects both how we eat and how our metabolism works.
Guidelines for adults on a fasting test:
- normal level — below 1.7 mmol/L;
- borderline — 1.7 to 2.3 mmol/L;
- high — 2.3 to 5.6 mmol/L;
- very high — above 5.6 mmol/L (there is a risk of inflammation of the pancreas).
If the level stays high for a long time, the risk of heart and vascular disease, fatty liver and diabetes goes up. Omega-3 in large doses helps lower this number because it reduces the production of fat in the liver.
Why Some Fats Are Solid and Others Liquid
Fats are made of very long molecules. In some fats they are straight and fit tightly against each other, so these fats are solid, like butter and lard. In others the molecules are bent and do not pack tightly, so the fat stays liquid, like olive oil, sunflower oil or fish oil.
Omega-3 is among the most “bent” fats. This makes it flexible and fluid, but also very vulnerable: it spoils quickly from air, light and heat. Hence some practical rules:
- store supplements in a cool, dark place;
- do not buy them in stock for years ahead;
- if fish oil tastes bitter or smells sharp, it is better not to take it.
It is precisely because of this “instability” that manufacturers turn liquid oils into solid ones (this is how margarine is made).
Where to Get Omega-3
The best source is food. Most omega-3 is found in fatty fish: salmon, mackerel, herring, sardines, trout.
If you do not eat fish. Plant sources (flax, chia, walnuts) are good for you, but they do not fully replace fish: the body converts them poorly into the forms it needs. For vegetarians, supplements made from algae are a better fit. They contain the “fish” forms directly, because algae are their original source.
What to Watch Out For
High-dose supplements are not harmless. They can increase the tendency to bleed and, according to some data, the risk of heart rhythm disturbances. So it is best to take large doses only after talking to a doctor, especially if you already take blood-thinning medication.
In Short
- Omega-3 is a healthy fat that the body hardly produces on its own.
- The most valuable forms are found in fatty fish and seafood.
- Its effect on blood fat is best proven; for the heart, it is fish in the diet that helps.
- It is important for the brain, eyesight and a child’s development.
- Plant sources are good but only weakly replace fish; algae supplements suit vegetarians.
- Supplements should be stored in a cool, dark place, and large doses should be taken under a doctor’s supervision.