Polyunsaturated fatty acid facts for kids
Polyunsaturated fatty acids, often called PUFAs or polyunsaturated fats, are a type of fatty acid that have more than one special link, called a double bond, in their structure. These fats are very important for your body and are found in many foods.
When we say a fat is "unsaturated," it means its molecules don't have the maximum possible amount of hydrogen atoms. Polyunsaturated fats can be found in foods like nuts, seeds, fish, and certain oils. They come in two main shapes: cis and trans. The cis shape is usually bent, while the trans shape is straighter.
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What are Polyunsaturated Fats?
Polyunsaturated fats are different from saturated fats. Saturated fats have a straight chain of atoms, which makes them solid at room temperature, like butter. Polyunsaturated fats, because of their double bonds, have bends in their chains. This often makes them liquid at room temperature, like vegetable oils.
Some polyunsaturated fats are also used outside of food. For example, drying oils, like linseed oil (from flax seeds) and tung oil, are polyunsaturated fats. They react with oxygen in the air to form a solid film. This is why they are used to make paints and varnishes that dry hard.
How are PUFAs Structured?
Scientists use special names to describe where the double bonds are located in a fatty acid.
- The carbon atom closest to one end of the chain is called the alpha carbon.
- The carbon atom at the very end of the chain, which has a methyl group, is called the omega carbon.
This "omega" naming helps us classify PUFAs. For example:
- Omega-3 fatty acids have their first double bond three carbons away from the omega end.
- Omega-6 fatty acids have their first double bond six carbons away from the omega end.
These omega-3 and omega-6 fatty acids are very important for your health.
Where Can You Find PUFAs?
You can find polyunsaturated fats in many healthy foods.
- Omega-3 fats are common in:
- Fatty fish like salmon, mackerel, and sardines.
- Flaxseeds and flaxseed oil.
- Chia seeds.
- Walnuts.
- Omega-6 fats are common in:
- Vegetable oils like sunflower oil, safflower oil, and corn oil.
- Nuts and seeds.
Types of PUFAs
Polyunsaturated fatty acids can be grouped based on their structure and length:
- Short-chain PUFAs have 18 carbon atoms.
- Long-chain PUFAs have 20 or more carbon atoms.
The most well-known types are the omega-3 and omega-6 fatty acids. Some of these are called essential fatty acids because your body cannot make them. You must get them from the food you eat.
Omega-3 Fatty Acids
Omega-3s are known for their health benefits. Important omega-3s include:
- Alpha-linolenic acid (ALA)
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
Omega-6 Fatty Acids
Omega-6s are also important for health. Key omega-6s include:
- Linoleic acid (LA)
- Arachidonic acid (AA)
Health Benefits of PUFAs
Polyunsaturated fats are often called "good fats" because they are beneficial for your body, especially compared to saturated fats. While some fat is necessary in your diet, it's generally best to choose unsaturated fats more often.
- Heart Health: Research suggests that omega-3 fatty acids, found in fish and certain oils, may help lower the risk of heart attacks. Some studies also indicate that omega-6 fatty acids, found in oils like sunflower oil, might help reduce the risk of heart disease.
- Brain and Vision: Docosahexaenoic acid (DHA), an omega-3 fat, is very important for the structure of your brain and for good vision. It's linked to better thinking and learning abilities.
- Pregnancy: For pregnant and breastfeeding women, consuming more polyunsaturated fats is recommended. This helps ensure the baby gets enough DHA, which is vital for their brain development. PUFAs may also slightly increase the length of pregnancy, reducing early premature births.
- Cancer Research: Studies on PUFAs and cancer have had mixed results. Some research suggests that higher levels of omega-3s might be linked to a lower risk of certain cancers, like breast cancer and colorectal cancer. However, more research is needed to fully understand these connections.
Cooking with PUFAs
When cooking with oils that contain polyunsaturated fatty acids, it's good to know that they can change when heated to very high temperatures (around 150°C or 300°F). High heat can cause them to break down. This is why some oils are better for high-heat cooking than others.
Images for kids
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Chemical structure of the polyunsaturated fat linoleic acid.
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3D representation of linoleic acid in a bent shape.
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Chemical structure of alpha-linolenic acid (ALA), an important omega−3 fatty acid.
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