Fatty acids are necessary for the normal functioning of all systems in the body. People can only get essential fatty acids from food sources, while it can create nonessential fatty acids.

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.

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

Read more to learn about essential fatty acids, examples of foods that contain them, and the symptoms of essential fatty acid deficiency.

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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.

Certain foods are high in essential fatty acids.

Omega-3s

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

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

Sources of DHA include:

Sources of EPA include:

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

Omega-6s

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

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

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

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

Symptoms of EFAD may include:

Diagnosis

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.

Treatment

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.

Essential fatty acids are fatty acids the body cannot produce on its own. They play a key role in various bodily functions, including heart health, cancer prevention, cognitive function, skin health, and obesity prevention.

Good food sources of essential fatty acids include vegetable oils, nuts, and oily cold-water fish. Supplements containing essential fatty acids include flaxseed oil, fish oil, cod liver oil, and krill oil.

Essential fatty acid deficiency is rare. If a person has the condition, a doctor may recommend a diet high in fatty acids or prescribe an IV liquid emulsion.