What Do Omega-3 Fatty Acids Do to Your Body?
A registered dietitian nutritionist provides an evidence-based explanation
Medically reviewed by Melissa Nieves, LNDMedically reviewed by Melissa Nieves, LND
Omega-3 fatty acids (omega-3s) are essential fats that your body needs for various functions. They are a type of polyunsaturated fat, which is considered a "healthy fat."
Omega-3s are vital to heart health, brain health, fetal and infant development, cell structures, and more.
This article covers omega-3 fatty acids, including what they are, their potential health benefits, food sources, dietary supplements, and safety considerations.
Ilja Enger-Tsizikov / Getty Images
Squeezing fresh lemon onto omega-3-rich oysters.What Do Omega-3 Fatty Acids Do to Your Body?
Omega-3 fatty acids have been linked to a variety of nutrition and health benefits.
Research shows that omega-3s may lower the risk of heart disease, cancer, arthritis, and other chronic conditions.
Omega-3s may also help reduce the risk of the following:
High cholesterol and triglycerides (fats in the blood)
Mental decline
Many studies have been conducted on omega-3 fatty acids and their potential health benefits. Some of the research is outlined below.
Heart Health
Omega-3 fatty acids have long been used for their potential heart health benefits.
A systematic review and meta-analysis found that the use of omega-3 fatty acids (especially EPA) was associated with reduced cardiovascular mortality and other outcomes.
Recent research also shows that taking 2–3 grams (g) of DHA and EPA per day may reduce blood pressure and triglycerides and increase high density lipoprotein (HDL) cholesterol ("good" cholesterol). These effects are thought to reduce the overall risk of heart disease.
Brain Function
Supplementing with omega-3s has been associated with better brain function and mental health.
According to one review, omega-3 fatty acids may increase oxygen and blood circulation to the brain, leading to improved mental performance. The review also notes several studies that have found links between omega-3 supplementation and improvements in memory and learning as well as protection against age-related cognitive decline.
Additional research shows that omega-3s may also help reduce symptoms of depression when used alongside antidepressants. However, more research is needed in this area.
Inflammation and Joint Health
Omega-3s have been found to reduce pain and inflammation associated with various types of arthritis.
Preliminary research shows that omega-3 fatty acids may help treat osteoarthritis (OA), a degenerative joint disorder. Omega-3s are thought to help reduce OA-related inflammation and pain and slow the breakdown of cartilage seen in the disorder. Researchers feel that more studies are needed in this area, though.
Omega-3s may also be beneficial for rheumatoid arthritis (RA), an inflammatory autoimmune disease (when the immune system mistakenly attacks tissues and organs, which, in RA, mainly is the tissue protecting joints). According to one review, increased consumption of omega-3 fatty acids from mainly fish sources decreases pain and other symptoms of RA.
Skin Health
Some people use omega-3s with the hope of improving the health of their skin and hair.
Omega-3s are thought to improve the health and function of the outer layer of the skin. Studies show that both oral and topical omega-3s may improve skin issues like inflammation, hyperpigmentation, dry skin, wounds, and itching.
Initial research also shows that omega-3 fatty acids may stimulate hair growth, which may be useful for those experiencing hair loss. However, few human trials have been performed on the potential effects of omega-3s on hair health. Therefore, more research is needed.
Cancer Treatment & Prevention
Omega-3 fatty acid supplements are sometimes recommended as nutrition therapy for people with cancer.
Researchers from one review found that omega-3s may aid standard cancer treatments and help reduce possible side effects, such as inflammation, pain, poor appetite, and depression. According to the review, omega-3s are crucial to cell signaling and, thus, may influence certain cell pathways involved in the cancer process.
Other research suggests that the anti-inflammatory properties of omega-3 fatty acids may also help with the prevention of certain cancers, including breast cancer and colorectal cancer. However, more research is needed.
Age-Related Macular Degeneration
Age-related macular degeneration (AMD) is a condition that impacts the retina and may reduce vision in some older adults.
Many healthcare providers recommend omega-3s to their patients for AMD. However, research results on the effectiveness of omega-3s for eye health are mixed.
Studies have shown a link between higher omega-3 fatty acid intake and a lower risk of developing AMD. Research also suggests that omega-3s may slow the progression of AMD.
However, two large-scale human trials found that omega-3 supplementation did not significantly affect AMD development or progression.
What Are Omega 3 Fatty Acids?
Omega-3 fatty acids are one of the two main types of polyunsaturated fatty acids (along with omega-6 fatty acids). Compared to saturated fats, polyunsaturated fats have more double bonds in their chemical structures.
Omega-3s are found in both animal- and plant-based foods as well as dietary supplements. They are considered "essential" because they must be obtained through the diet. Your body can't make omega-3 fatty acids on its own.
There are three types of omega-3 fatty acids:
Eicosapentaenoic acid (EPA)
Docosahexaenoic acid (DHA)
Alpha-linolenic acid (ALA)
In the body, small amounts of ALA are converted to EPA and DHA. However, it's recommended that you still get plenty of EPA and DHA from your diet.
All three omega-3 fatty acids are important to your health, with roles in cell structure and integrity, fetal brain development, infant growth, inflammation, joint health, heart health, and cognitive ability.
Food Sources of Omega-3 Fatty Acids
You can find omega-3 fatty acids in a variety of foods, including both animal and plant foods. EPA and DHA are mostly found in animal foods, while ALA is primarily found in plant-based foods and oils.
Fatty fish is considered the best source of omega-3s. Animal foods that contain omega-3 fatty acids include:
Some plant sources of omega-3s in order of abundance are:
Flaxseed and flaxseed oil
Soybean oil
Certain types of beans, such as kidney beans
Some foods and drinks, such as eggs, yogurt, juice, milk, soy milk, and infant formula, may also be fortified with omega-3 fatty acids.
Adult males should aim for 1.4 g of omega-3s daily, while adult females need about 1.1 g. Those who are pregnant or breastfeeding need more omega-3 fatty acids per day, 1.4 g and 1.3 g, respectively.
Omega-3 Supplements
A food-first approach—that is, getting the nutrients your body needs from food before trying supplements—is always recommended.
Research suggests that omega-3-rich foods (like fatty fish) provide more benefits than dietary supplements.
However, supplements are sometimes necessary. For example, a healthcare provider may recommend taking an omega-3 fatty acid supplement for a specific health condition.
For example, omega-3 supplements have been linked to health benefits, like reduced triglycerides and RA symptom relief.
You can find both animal-based and plant-based omega-3 supplements that are made from:
Algal oil (omega-3 supplement from algae)
There are no strict dosage recommendations for omega-3 fatty acid supplements. However, the Food and Drug Administration (FDA) recommends using no more than 5 g of omega-3 fatty acids daily.
Using omega-3 supplements, especially in excess, may cause unpleasant side effects. Fortunately, these are usually mild. Possible side effects include bad breath, foul-smelling sweat, headache, heartburn, nausea, and diarrhea.
To lower the risk of side effects, use omega-3 supplements only as directed.
Explainer
In the United States, the FDA does not regulate supplements in the way it does for prescription drugs. This means some supplement products may not contain what the label says. When choosing a supplement, look for third-party tested products and consult a healthcare provider, registered dietitian nutritionist (RDN or RD), or pharmacist.
Safety Considerations
Certain precautions should be taken before using omega-3 fatty acid supplements.
Some people may be allergic to ingredients found in omega-3 supplements. People with a fish allergy should not use omega-3 supplements derived from marine sources.
Always check a supplement's ingredients list for known allergens. Seek immediate medical attention if you have a severe allergic reaction (itching, hives, shortness of breath) to an omega-3 supplement.
People with certain health conditions should check with a healthcare provider before using omega-3 fatty acid supplements. Talk with a healthcare provider if you have the following:
People who are pregnant or breastfeeding should also check with a healthcare provider regarding the safety of omega-3 supplements.
Additionally, omega-3 fatty acids may interact with various medications, causing the medication to not work properly.
Possible interactions include:
Anticoagulants
Antiplatelets
Estrogen-containing birth control
Estrogen replacement therapy
It's best to be cautious and talk with a healthcare provider before starting any new dietary supplement. This is especially true if you have health conditions or take prescription medications.
Summary
Omega-3 fatty acids are polyunsaturated fats that your body needs for cell integrity, brain development, energy, and other important processes. Your body cannot make omega-3s, which means you have to get them through your diet.
Research shows that the three types of omega-3 fatty acids, EPA, DHA, and ALA, may be beneficial for heart health, brain function, joint health, and skin health. EPA and DHA are found in fatty fish and a few other animal foods, while ALA is found in plant foods.
Some people are recommended to take an omega-3 supplement for a health condition or other reason. However, side effects are possible and omega-3 supplements may not be right for everyone. Talk with a healthcare provider to learn more about omega-3 fatty acids.
Read the original article on Verywell Health.
