Fat fish protects your heart

Polyunsaturated fat, Omega 3 and Omega 6

Polyunsaturated fat is healthier than saturated fat and it can, in fact, reduce the risk of heart and vascular disease, by reducing the amount of harmful LDL-cholesterol in the blood. The most important polyunsaturated fats are Omega 3 and Omega 6.

Most of us would do well to eat less saturated fat and more polyunsaturated fat. An easy way to do this is to choose soft instead of hard fat. In general, it is true that the harder the fat at room temperature, the more saturated fat it contains. In other words, choose low fat margarine instead of butter and use liquid margarine or oil for cooking!


On this page:

• What is polyunsaturated fat?
• Where is polyunsaturated fat found?
• Why do we need polyunsaturated fat?
• How much polyunsaturated fat do we need?
• Tips for eating more polyunsaturated fat


 

What is polyunsaturated fat?

The most important polyunsaturated fats are Omega 3 and Omega 6. Omega 3 and Omega 6 are in fact the names of two families of polyunsaturated fats. In these families there are different chain lengths of fatty acids that have different functions in the body.
 
The parent fatty acid in the Omega 3 family is called alpha-linolenic acid. The parent fatty acid in the Omega 6 family is called linoleic acid. The parent fatty acids are medium chain fatty acids that can to some extent be converted into long chain fatty acids in the body. 

Where do we find polyunsaturated fat?

• Long chain Omega 3 is found in e.g.
• Fat fish such as salmon, mackerel, herring, Baltic herring and sardines
• Shellfish
• Some types of algae.

Short chain Omega 3 is found in e.g.

• Rapeseed oil and cooking fat made from rapeseed oil
• Linseed and linseed oil
• Walnuts
• Oil from camelina, [also called wild flax] which is contained in many cooking fats
• Leaf vegetables

Omega 6 is found in e.g.

• Maize oil
• Sunflower oil
• Soya oil
• Sesame seeds and sesame seed oil

Why do we need polyunsaturated fat?

Most of the fats we need can be formed from carbohydrates and protein. The exceptions to this are the two parent fatty acids in the Omega 3 and Omega 6 families. They are vital, or essential, fatty acids. The body is not able to produce them by itself, so we have to get them from food. Read more about fatty acids in Facts on fat.


Omega 3 and Omega 6 have many different tasks to perform in the body. They are necessary for the brain and the eyes to be able to develop and function, and also for the body to be able to build and repair cells. They also affect the regulation of blood pressure, kidney function and our immunological defence. Omega 3 reduces blood clotting and thus reduces the risk of thrombosis. Omegas 3 and 6 are necessary for the growth and normal development of foeti and young children.
 

Both Omega 3 and Omega 6 are important

Omega 3 and Omega 6 affect, to various degrees, the function of the body. In many cases Omega 3 tones down the effects of Omega 6, for example with regard to blood clotting and immunological defence. The fats interact with each other and therefore it is important that we get an adequate amount of both of them in our food.


Omega 3 and Omega 6 are often found together in the same foodstuffs. There is often a larger amount of Omega 6 than Omega 3 in food, which makes it easier to take in a sufficient amount of Omega 6. Some foods are good sources of both Omegas 3 and 6, for example, rapeseed oil and cooking fats that contain a large amount of rapeseed oil.

Fat fish protects against heart disease and vascular disease

The very long chain fatty acids that are present in the Omega 3 family are called DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid). They are also called fish fatty acids because they are mainly found in fish and shellfish. In particular, DHA and EPA have been found to protect against heart and vascular disease.

There is a great deal of research into whether Omega 3 may also affect e.g. depression, adhd [Attention Deficit Hyperactivity Disorder] and Alzheimer’s disease. So far there is no evidence to prove this.

How much polyunsaturated fat do we need?

5 to 10 per cent of the energy we obtain from food should come from polyunsaturated fats, of which about 1 percentage point should be from Omega 3. This corresponds to about 2.5 to 3 grams of Omega 3 fat per day. That is, the amount of Omega 3 present in one portion of salmon, or 1 to 2 tablespoons of rapeseed oil.


People who eat a varied diet, which includes fish, seldom have difficulty in obtaining a sufficient amount of the long chain fatty acids DHA and EPA.


It is particularly important for pregnant women to eat fat fish once a week, since the foetus needs DHA and EPA in order to develop normally. Farmed salmon, mackerel and pickled herring are fat fishes which can be eaten safely, with no need to worry about environmental pollution.

Diet supplements

The Swedish National Food Agency does not recommend healthy people to eat extra supplements of Omega 3, for example, in the form of fish oil. It is better to eat a varied diet, with fish three times a week, one meal of which includes fat fish. Eating a varied diet is sufficient to obtain all the nutrients necessary for a healthy life.
 

Vegetarians and vegans

It is important for people who do not eat fish, for example, vegetarians and vegans, to obtain the Omega 3 parent fatty acid, which is present in rapeseed oil, linseed, walnuts and leaf vegetables. A small amount of this can be converted in the body into the long chain fatty acids DHA and EPA. 
 

Ways to eat more polyunsaturated fat

Here are some tips for eating more polyunsaturated fat and less saturated fat:

• Use liquid margarine or oil when cooking and baking, preferably those that contain rapeseed oil.
• Use low-fat margarine on sandwiches. 
• Eat fish three times a week, of which one meal includes fat fish.
• Choose dairy and cured meat products labelled with the keyhole symbol.

Source: Livsmedelsverket.