What are omega-3 fats?

When it comes to health, not all fats are created equally.

Certain types of fat, when eaten in excess, may harm your health, while other types of fat are beneficial. Omega-3 fats are a type of fat that plays an important role in our health. Read on to learn more about these fats, why they are important to your health, and how to include them as part of a well-balanced diet.

Research has mainly focused on three specific omega-3 fats: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). ALA is an essential fatty acid, meaning our bodies can't make it, so it must come from the diet. The body can convert ALA into EPA and then to DHA. However, this only happens in small amounts.

Omega-3 fats are part of our cell walls, and high levels of DHA specifically have been found in the brain, eyes and sperm cells.

The possible health benefits of omega-3s have been the focus of a lot of scientific research. Studies show that people who consume diets rich in seafood tend to have a lower risk of several chronic diseases, including heart disease. Research has not yet proven whether it is the omega-3 fats that specifically offer this benefit or another factor. Still, there seems to be a link between omega-3s and improved heart health. Omega-3s may also play a role in infant vision and neurological development. Some research also suggests that omega-3s can help reduce the risk of breast cancer, colorectal cancer, dementia, cognitive decline, Alzheimer's disease and age-related macular degeneration.

Omega-3 fats are found in a wide variety of foods. Cold water, fatty fish contain EPAs and DHAs. This includes salmon, mackerel, trout, sardines and herring. ALA is found in many plant oils, like flaxseed and canola oil. Flaxseeds, chia seeds and walnuts also contain ALA.

ALA is the only omega-3 fat with a recommended intake, and it is based on an individual's age and sex.

Aim to eat at least two servings of fatty fish per week. Studies have shown that eating two 4-ounce servings of fish a week may offer protection from heart disease. However, it is important to know that women who are pregnant or breastfeeding should avoid fish that may contain high levels of mercury. Varieties of fish that contain lower levels of mercury include salmon, herring, sardines and trout.

An omega-3 fat deficiency occurs when blood and tissue levels of these fats are low. No cut-off level has been established for when health may be negatively impacted.

In the U.S., a true omega-3 fat deficiency is rare, but signs of a deficiency may include:

• Skin irritation
• Rough, scaly skin

Some people may choose to take omega-3 supplements, such as fish oil, krill oil, cod liver oil and algal oil. However, it is preferable to take in omega-3 fats from foods instead of supplements.

Before starting supplements, talk to your healthcare provider to discuss the dosing and safety of these supplements.

Omega-3 acid ethyl esters are prescription-strength omega-3 fats. Healthcare providers may prescribe this medication along with a healthy diet to help manage high triglyceride (a type of fat in the blood) levels in the blood.

There is little risk in consuming foods rich in omega-3 fats. Note that omega-3 supplements may cause side effects, such as bad breath, an unpleasant taste in your mouth, nausea, heartburn, stomach upset, diarrhea, headache and foul-smelling sweat.

Omega-3 supplements may also interact with certain medications, including those that thin the blood, such as warfarin.

Omega-3 fats are an important nutrient for good health. A nutritious diet, regularly consisting of fish, usually provides enough of it. Always remember to talk to your healthcare provider if you're considering an omega-3 supplement.

Published May 2022.