There are two types of fatty acids: essential and nonessential. The body can create nonessential fatty acids by converting amino acids in the foods a person eats.

However, the body cannot create essential fatty acids. It can only get them directly from food sources. Essential fatty acids include linoleic acid (LA), an omega-6 fatty acid, and alpha-linolenic acid (ALA), an omega-3 fatty acid.

Check out Pritish Kumar Halder’s illustration of essential fatty acids, their sources and treatment.

These fatty acids make hormones that regulate the immune system and central nervous system.

What are essential fatty acids?

Essential fatty acids are a type of polyunsaturated fatty acid. There are two categories of essential fatty acids: omega-3 and omega-6.

The numbers refer to the position of the first carbon double bond counting from the tail of the chain. For example, in omega-3 fatty acids, the first carbon-carbon double bond is the third bond from the end. In omega-6 fatty acids, it is sixth from the end.

Omega-3 and omega-6 fatty acids are necessary for the body to function correctly. They make compounds called eicosanoids, which are important hormones that control the immune system, nervous system, and other hormones.

However, the eicosanoids from omega-3 and omega-6 fatty acids act differently.

Eicosanoids from omega-3 fatty acids promote heart health, while eicosanoids from omega-6 increase immune response, inflammation, and blood pressure.

Because the two omega fatty acids can produce opposite effects, a person should try to balance them in their diet.


Some research suggests a possible link between omega-3 fatty acids and a lower incidence of heart disease and certain cancers. They may also help with symptoms of rheumatoid arthritis.

A 2012 review highlighted older studies suggesting omega-3 fatty acids may also help prevent bowel disease, asthma, and some mental health conditions.

However, it is important to note that most of the research on omega-3s has focused on fatty acids from animal sources, like fish and fish oil, rather than plant-based sources. Some of the benefits observed in studies may come from consuming fish, not the omega-3 fatty acids themselves.

Essential fatty acids foods

Certain foods are high in essential fatty acids.

Essential fatty acid structure


Plant sources of omega-3s, also called ALAs, include:

  • flaxseed oil
  • chia seeds
  • walnuts
  • flaxseeds
  • walnut oil
  • canola oil
  • soybean oil
  • mustard oil
  • tofu

Animal sources of omega-3s are called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).

Sources of DHA include:

  • mackerel
  • salmon
  • herring
  • fish oil
  • tuna
  • anchovies
  • sardines
  • sea bass
  • swordfish

Sources of EPA include:

  • menhaden
  • salmon
  • trout
  • halibut
  • herring
  • shad
  • sablefish
  • wolffish


Food sources of omega-6s, also called LAs, include:

  • canola oil
  • soybean oil
  • corn oil
  • sunflower oil
  • safflower oil
  • chia seeds
  • walnuts
  • hazelnuts
  • almonds
  • Brazil nuts

Other sources of essential fatty acids

People commonly take omega-3 essential fatty acid supplements in the form of fish oils. These include:

  • fish oil
  • cod liver oil
  • krill oil

People who do not consume fish can try algal oil, a plant-based omega-3 supplement made from algae.

Essential fatty acid deficiency

Essential fatty acid deficiency (EFAD) is rare, especially in people who eat a varied diet. Certain conditions that affect absorption or metabolism may cause EFAD.


Symptoms of EFAD may include:

  • hair loss
  • a dry, scaly rash
  • slow wound healing
  • decreased growth


To determine if a person has EFAD, a doctor will perform a physical examination to look for features such as dry, scaly skin.

They may also ask questions about wound healing, growth, and susceptibility to infection.

Doctors may do blood and urine tests to determine liver and kidney function and measure the levels of essential fatty acids.


If a person receives a diagnosis of EFAD, a doctor may suggest they eat a diet rich in nut butters, vegetable oils, and oily fish.

They may also suggest an intravenous liquid emulsion. These emulsions usually consist of soybean oil and other fatty acid sources.