Omega 3 fatty acids uses, benefits and side effects

Omega 3 fatty acids are not a single component; they are group of compounds. They are essential fatty acids and important for human health. These fatty acids are polyunsaturated. The body can’t produce them. So they have to get into the body through foods. The most common Omega-3 fatty acids are ALA, EPA and DHA. Among them the ALA (alpha-linolenic acid) is found in plant such as nuts and seeds. On the other hand the EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are found in certain fish. Many Research shows that they have many health benefits such as reduce inflammation and lower the risk of heart disease, cancer, and arthritis. If the body has lower amount of omega-3 fatty acid then we experience with many problems include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.
Structurally the fatty acids have two ends; the carboxylic group (-COOH) end which is ‘beginning’ of the chain and the methyl (-CH3) end which is ‘tail’ of the chain. The 1st double bond is located at number three position from the ‘tail’ end, so it is called omega-3.

Types of omega 3 fatty acids

In fact at least 11 different types of omega-3 fatty acids are discovered. For example:

  1. ALA (alpha-linolenic acid)
  2. EPA (eicosapentaenoic acid)
  3. DHA (docosahexaenoic acid)
  4. Hexadecatrienoic acid (HTA)
  5. Stearidonic acid (SDA)
  6. Eicosatrienoic acid (ETE)
  7. Eicosatetraenoic acid (ETA)
  8. Heneicosapentaenoic acid (HPA)
  9. Docosapentaenoic acid (DPA)
  10. Tetracosapentaenoic acid
  11. Tetracosahexaenoic acid

Among them the three most important omega 3 fatty acids are ALA, EPA and DHA.
ALA is mostly found in plants. It construct with 18 carbons containing three double bonds. It needs to be converted into the EPA and DHA before using by the human body. If it does not convert then it remains inactive and simply store in the body for used as energy.
EPA is mostly found in animal foods like fish. The EPA carbon chain contains 20 carbons. It has 5 double bond in each molecule. On the other hand DHA also found in sea foods like fish and algae. It has 22 carbon chains with 6 double bonds. Both of them play numerous physiological roles in human body.

What is the use of omega 3 fatty acids?

The fatty acids have many functions. Normally they are used for energy but they have important roles in neurological function, cell membrane maintenance, mood regulation and hormone production. Moreover they are also used in many health problems such as inflammation, heart health and brain function.

Omega 3 health benefits

Many studies show that omega-3 fatty acids have various benefits.


Some researchers have found that the people who took foods with high levels of omega-3s have lower levels of depression. On the other hand, some studies found no benefit.

Baby development

Several studies show that it is important for visual and neurological development in infants.


Several studies show that a diet high in omega-3s lowers inflammation which is a key component for asthma.

Attention deficit/hyperactivity disorder (ADHD)

Some studies have proven its effectiveness that fish oil can reduce the symptoms of ADHD in some children and improve their mental skills, like thinking, remembering, and learning, improve sleep disturbances, improve behavioral problems.

Alzheimer’s disease and dementia

Some research proves that omega-3 fatty acids is associated with protection against Alzheimer’s disease and dementia, and have a positive effect on age-related cognitive decline. But that’s not certain yet.

High cholesterol

There is strong evidence that fish oil supplements increase HDL cholesterol and reduce triglyceride levels which promote heart health. Similarly walnuts also reduce total cholesterol and triglycerides in people with high cholesterol levels.

High blood pressure

Scientists believe with the analysis of clinical studies that diets rich in omega-3s lower blood pressure in people with hypertension.


With several clinical studies we know that Omega 3 fatty acids from fish oil can help lower triglycerides and raise HDL. High triglyceride and low HDL levels are often found in diabetes. So consuming fish oil supplements may help people with diabetes. This result would not found with the fatty acids from nuts and seeds.


Some studies suggest that omega-3 fatty acids can increases the level of calcium in the body and slowdown the bone loss. As a result improve the signs of osteoarthritis and joint pain.

Menstrual pain

In one clinical study shows that It can reduce menstrual pain. It may be more effective than ibuprofen, an anti-inflammatory drug.


Preliminary studies suggest that consuming fish oil daily can slowdown the progression of colon cancer, breast cancer and prostate cancer in people with early stages of the disease. Moreover, they can reduce the risk of those cancers. If you have suffering from any of these cancers, then ask your doctor before taking any supplements.

hair loss

Omega 3 fatty acids have anti-inflammatory properties, which can help to open the hair follicles and promoting healthy hair growth.

Weight problem

Body mass index (BMI) is a number that is used as a screening tool to identify probable weight problems. It is calculated from a person’s weight and height. If you consume of omega-3s then it will improve the BMI and can reduce the risk of having a weight problem.

omega 3 fatty acids side effects

Although omega-3 fatty acids are good for health but some people may experience some side effects while taking more fatty fish. Some oily fishes such as mackerel, wild swordfish, tilefish, and shark have higher levels of harmful contaminants like mercury, PCBs (polychlorinated biphenyls), or other toxins. FDA recommends that pregnant or nursing women and young children should avoid taking these types of fish at higher levels. Fish oil can cause stomach pains, nausea, gas, bloating, belching, and diarrhea, headache, allergic reactions. Moreover omega-3 can cause bleeding problem. So if you have a bleeding condition or take blood-thinning medications, you should take a doctor advice before using any omega-3 supplements. A undependable research shows that ALA may increase the risk of prostate cancer in men.

What are the symptoms of lack of Omega 3?

A number of physical symptoms are found that indicate fatty acids deficiency. The common signs are following: Rough or dry ‘bumpy’ skin, Dry, dull or ‘lifeless’ brittle hair and dandruff, Soft, peeling or brittle nails, Excessive thirst, frequent urination, Sleep problems, Attention problems, depression. If you experience these symptoms, then you may have an omega-3 deficiency.

What are good sources of omega 3?

There are 11 types of omega-3 fatty acids. We know that our body can’t produce these fatty acids. Therefore we have to intake them into the body with our daily foods. The most important omega 3 fatty acids are ALA, EPA and DHA. Among them EPA and DHA are found in fish and shellfish. On the other hand, ALA is found in some plant foods, including certain nuts and seeds. The ALA is not effective for human body and the health effects come mostly from EPA and DHA, so it needs to turn into usable DHA and EPA. However, many human bodies do not convert very effectively for many factors including lifestyle (Alcohol, caffeine, nicotine) and foods habits (such as processed and refined foods). Although has an ongoing debate in the nutrition community.

As the many sea food are high in DHA and EPA, many nutrition doctors advice us to take seafood several times in every weeks. The natural good sources of omega-3 fatty acids can be grouped by following way:

  • Oily fish: salmon, sardines, mackerel, anchovies, herring, halibut, albacore, trout, catfish, cod, tuna, Bluefish, Sturgeon
  • Shellfish: Shrimp, clams, lobster, crab
  • Nuts and Seeds: Walnuts, butternuts, Brazil nuts, hazelnuts, almonds, chia seeds, flaxseeds, hemp seeds, mustard seed, linseeds, cashews, rapeseed (canola oil), pumpkin seeds, soybeans (good sources of ALA).
  • Vegetables: many vegetables like green leaf (good sources of ALA).

Besides these other natural sources are egg yolks, sea krill and algae. When possible, try to get omega-3s from foods rather than supplements. Furthermore, the conversions are dependent on adequate levels of other nutrients, such as vitamins B6 and B7, copper, calcium, magnesium, zinc and iron.

Omega 3 fatty acid supplement

If you don’t take a lot of omega-3 foods and have deficiency signs, then omega-3 supplements can be useful for you. The common Omega-3 dietary supplements are fish oil, krill oil, cod liver oil, and algal oil. The supplements can be found in liquid, capsule and pill form.

Omega 3 fish oil dosage

The effective dosages depend on numerous factors. Different types of fish, nuts or seeds contains different amount of omega-3 fatty acids. Similarly different supplements have variable amount of EPA and DHA. So the dosing should be based on the amount of EPA and DHA. Yet there is no established dose for children. The safe amount declared by FDA up to 3000 mg per day whereas EFSA declared up to 5000 mg per day. For adult, different health conditions may requires variable amount omega 3 fatty acids but should not consume more than 3 grams daily without the recommendation of a health care provider. The people who are experience with heart disease are usually advised to take 1000 mg per day. Many studies show that per day 500-2000 mg can reduce the symptoms of depression and anxiety.

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