Fish oil is now a household name in the US, thanks to the vast array of health benefits and the over-enthusiastic advertisements in the media. It is an irrefutable fact that fish oil is the biggest natural source of omega-3 fatty acids. Omega-3 fatty acids are known to improve your health and decrease metabolic risk factors. The fish oil benefits your health in several ways such as it maintains a healthy cardiovascular, aids as a supplement in weight reduction, helps in fighting different kinds of cancers, helps you during pregnancy, increases the sperm count in male, boosts the immune system, helps in various skin diseases such as eczema, psoriasis, etc.
Moving ahead, you will learn more about the basics of fish oil, omega-3 fatty acids in detail, myths and hypes around fish oil benefits, associated risks, etc. Also, we will let you know if there are any alternatives to fish oil supplements.
What is fish oil?
As the name suggests, fish oil is the industrially produced oil obtained by processing fatty fish tissues through a series of thorough and methodical processes. You can either get fish oil from eating the fish itself or from any good fish oil supplements available in the nearby store.
There are some best fish available commonly in the market which can be an excellent source of fish oil are white fish, wild caught salmon, sardines, anchovies, herring, etc.
Nutritional composition of fish oil
All the claims on nutritional benefits of fish oil can be understood once you understand what it contains. Nutritional constituents of Fish oil (1) per teaspoon (4g) are:
|Total Omega-3-fatty acids||1084mg|
|Total Omega-6-fatty acids||90.6mg|
Vitamin B complex
What is omega-3 fatty acid?
Omega-3-fatty acids are one subgroup within hundreds of other such subgroups of fatty acids that are required by the body to function correctly. However, what sets this subgroup apart is the fact that they can only be obtained from sources outside of human body like animals and plants. The body does not synthesise them.
Fish oil is a vital source of omega-3-long-chain fatty acids (which have been aptly named so given their long names) like docosahexenoic acid (DHA) and eicosapentaenoic acid (EPA).
These are anti-inflammatory substances that are helpful in the reduction of blood cholesterol levels, various mental problems, reproductive and other systemic ailments. Some of these facts are clinically proven while research works are underway for others.
Omega-3 fatty acids sources
Cold water oily fishes are the best source of omega-3 fatty acids. They do not produce omega-3 fatty acids on their own but derive them from microalgae and planktons that are present in their diet. (2)
This implies that the higher a fish is in the food chain, the more omega-3 it stores in its body. You can verify this from the table below. (3) But the same logic dictates that as we go higher in the food chain, the amount of toxic substances (mercury, pesticides, etc.) that accumulate in the fish body also increase due to a phenomenon called biomagnification.
Hence, it’s not advisable to feed on fishes higher in the chain (e.g. albacore tuna, shark, king mackerel, tilefish and swordfish).(4)
|Food||Omega-3 content (mg/100g)|
|King salmon||> 2000|
|Greenshell / lipped mussels||950|
|Hoki (Blue grenadier)||410|
|Blue eye cod||310|
|Sydney rock oysters||300|
|Eggs, large regular||109|
|Giant tiger prawn||100|
|Lean red meat||31|
Fish Oil Supplements and prescribed dosage
A vast population in the United States takes fish oil supplements that are available in the form of tablets, capsules, emulsions, oils etc. without even considering how they may affect their health. These supplements might pose danger if not taken in accurate quantity, if the quality isn’t up to the mark, if the measurement of nutritional facts written on the label is incorrect, if there are formulation issues and spoilage. Let’s see them in detail.
Quantity- FDA recommends 3g/day of both EPA and DHA with no more than 2g/day from supplements. (5). More is not always right.
Product Purity- Fish oils are easily contaminated by mercury, dioxins, PCBs and other potentially toxic substances if not refined as per standards. (6)
Label Accuracy- Inaccuracy in measurements of various constituents in fish oil supplements may lead to overdose. Different findings show that the concentrations might vary from 8% to staggering 80%.
Formulation Issues- A study has found that one in every 24 enteric coated tablets, which are meant to release the contents later in the gastrointestinal tract, malfunctioned and released early than required. (7)
Spoilage- There are several factors which determine the shelf life of any fish oil supplements. Maximum product storage duration varies depending upon the raw materials, processing method, adherence to processing rules, packaging and storage conditions. If anything goes wrong, there’s a high probability of release of peroxides or free radicals, which are harmful to our body.
Note: FDA does not regulate the production of these supplements, and so they still form an unorganised market.
Alternative sources of omega-3 fatty acids – Fish oil substitutes
If you are vegan or vegetarian and do not want to consume animal or seafood based diets, then there are several plant sources from which you can obtain omega-3 fatty acids. Flax seeds, Hemp seed, Algal oil, Perilla oil, Spirulina, Walnuts, Chia seeds, Radish seeds and Brussels sprouts are great substitutes of fish oil or other animal-based diets. (8)
Top fish oil benefits on our health
Fish oil benefits our body in many ways. However, FDA has approved only a few facts, and rest are undergoing research and studies.
Fish oil helps in Hypertriglyceridemia condition
Hypertriglyceridemia is a condition where blood triglyceride (a type of fat) levels exceed the normal values. This condition may lead to disease like pancreatitis and coronary artery. Lovaza or Omega-3 acid ethyl esters is approved for reducing triglyceride levels in people with highly elevated TG levels. (9). FDA approves this fact.
Fish oil benefits the cardiovascular system
Research suggests that eating fish might prevent several heart diseases while people with pre-existing heart conditions can benefit by reduced chances of adverse events. Some fish oil benefits in cardiovascular problems are:
- Fish oil reduces the susceptibility of the heart to ventricular arrhythmia. Arrhythmias are a kind of dysfunction in the beating pattern of the heart. Fish oil consumption causes your heart to beat in the normal pattern.
- Anti-thrombogenic – Fish oil reduces artery clogging. If your arteries remain patent, blood flow to various organs remains intact. This reduces chances of myocardial infarction, strokes & organ infarcts.
- Prevents re-blockage after coronary artery bypass surgery leading to increased life expectancy.
- Promote nitric oxide-induced endothelial relaxation-Fish oil causes your blood vessels to dilate. This has a mild blood pressure lowering effect.
However, studies have failed to show benefits in reducing the incidence of heart attacks, strokes, claudication, angina & atrial fibrillation. (10)
Benefits of fish oil on Central Nervous System
- Attention deficit-hyperactivity disorder (ADHD)- Study suggests that if fish oil is started early after ADHD diagnosis in children aged 7-13, then fish oil benefits with improved attention spans, mental function and behaviour.
- Bipolar Disorder- Fish oil is useful in alleviating symptoms of depression but not mania. It may not be beneficial in manic episodes. Also, fish oil should be used along with conventional therapy. (11)
- Developmental Coordination Disorder (DCD)- Fish oil improves behaviour, reading, writing and spelling in DCD. However, it doesn’t improve motor skills.
- Dyspraxia – It is a movement disorder in children, and fish oil seems to help in this.
- Psychosis- Fish oil might inhibit the progress of psychotic episodes into full-blown illness. However, till date, medical research has not proved this association.
- Alzheimer’s Disease- A study suggests that fish oil slows down the decline in cognitive impairment but the condition is not (12)
- Autism– Fish oil have shown some quantitative improvement in autism, but research is still underway.
- Dementia- It is memory loss condition. Fish oils improve working memory.
- Dyslexia – This is a condition in which kids have difficulty in recognising alphabets, numbers and words. A study has shown that fish oil helps children in reading more number of words correctly.
- Epilepsy- Fish oil benefits people who have epilepsy. It reduces seizure occurrence in people with drug-resistant epilepsy.
- Post-traumatic stress disorder or PTSD- The Early inclusion of fish oil has shown benefits in the therapy for PTSD.
- Depression- A study suggests that fish oil marked improvement in the nutrition of brain linked with reduced duration of depressive episodes. (13)
- Anxiety- Several test tube studies on rats showed that fish oil could reverse the systems of anxiety. (14) However, no human studies have done so far.
Studies have failed to show any positive effects of fish oil in patients with multiple sclerosis and migraine headaches.
Helps in the reproductive system and during pregnancy
- Antiphospholipid syndrome (APS)- Fish oil reduced miscarriage rates in women suffering from APS (antiphospholipid syndrome) and increased chances of live birth.
- Sperm counts- Fish oil supplements can increase sperm counts in men along with better mobility and morphology of sperm. (15)
- Infertility- Evidence is suggesting that fish oil improves conditions like polycystic ovary syndrome and endometriosis, leading to better chances of conception.
- Pregnancy- Consumption of fish oil during pregnancy helps in fetal brain growth & Fish oil also reduces the chance of premature delivery and supports healthy labour. (16)
- Breastfeeding- Fish oil consumption during breastfeeding period is also associated with better neural development in babies.
- Dysmenorrhea (painful periods)- Fish oil can reduce painful cramps when taken along with Vitamin B12.
Fish oil benefits in bone and joint diseases
- Rheumatoid Arthritis- Oral intake of fish oil can provide relief from the bone disease like rheumatoid arthritis (17). It can also be given intravenously to reduce joint swelling and tenderness.
- Osteoporosis- Weakening of bones due to loss of calcium and other minerals can be slowed by fish oils alone or with calcium supplements.
Studies do not show any fish oil benefits in the treatments for osteoarthritis.
Fish oil supplements aids in weight loss
Combination of fish oil supplements along with regular exercise has shown to aid in weight loss especially in overweight people. (18) Also, fish oil supplements help in improving weight loss condition during cancer.
Helps in skin and hair diseases
- Skin health-Fish oil nourishes the skin providing it with fat-soluble vitamins and making it healthy and glowing. It also maintains the turgor, elastic texture and smoothness of skin. Fish oil can delay wrinkling, reduces age spots and sun spots.
- Psoriasis- Research shows fish oil benefit in patients dealing with psoriasis disease. However, the exact mechanism is unknown. (19)
- Raynaud’s Syndrome- It is a condition where some body parts may feel numb and cool in stress and cold conditions. Raynaud’s syndrome rarely occurs in patients taking fish oils since fats provide insulation. However, fish oil does not benefit patients with systemic sclerosis.
- Eczema- Fish oil benefits people suffering from eczema. It is believed that the effects might be due to the ability of fish oil to reduce leukotriene B4, which is an inflammatory substance that helps in eczema.
- Sunburns- Fish oil supplements provide relief in areas of sunburn on local application. (20)
- Dandruff- Fish oil can reduce dandruff but cannot cure it one hundred percent even if you take along with traditional selenium therapy.
Positive effects on Cancer
Omega-3 has antiproliferative effects, which can directly kill cancer cells. Indirectly, it also helps the immune system to kill cancer cells.
Research suggests that eating fish or having high blood levels of omega-3 is linked with lower risk of developing colon, prostate, breast (21) cancers. Fish oil is helpful in oral cancer, pharyngeal cancer, oesophageal cancer, rectal cancer, endometrial cancer & ovarian cancer.
In some places, fish oil is used as monotherapy under natural treatments for different types of cancers. Although, no study has been done in this regard.
- Diabetes- Fish oil reduces oxidative stress in the body. However, fish oil does not aid in the prevention of diabetes, but it reduces the progression, frequency and duration of macro and microvascular complications including those found in the eye, kidneys, brain vessels, etc. (22)
- Pre-diabetes– Studies suggest that fish oil may help prevent pre-diabetics from advancing to Type-2 diabetes.
Positive effects in eye-related diseases
- ARMD (age-related macular degeneration)- Evidence suggests that people who eat more fish may not develop ARMD in their young age as compared to those who don’t. (23)
- Cataracts- Fish oil can reduce the risk of developing incidence of early cortical cataracts.
- Dry eye syndrome- Fish oil helps in tear production and might improvise treatment for dry eye syndrome.
However, there is the doubtful efficacy of fish oil benefits in glaucoma & Behcet’s Syndrome.
Fish oil boosts your immune system
Animal tests have shown a boost in the immune system with fish oil intake. Fishes have a significant role to play in human health promotion. (24)
A study shows that people who eat fish three times a week may not get autoimmune diseases and their symptoms.
Positive effects of fish oil on Renal System
- Prevent Kidney damage after transplants- After any organ transplant, certain immunosuppressant drugs are given to a patient to avoid the rejection of donor organ by recipient immune system. One such drug is Cyclosporine. But this drug can result in kidney damage. Fish oil helps to improve kidney function in patients who are taking cyclosporine after transplant during the recovery phase.
- Ig A Nephropathy- It is an autoimmune disease of the kidney which causes a decline in kidney function. Long-term intake of fish oil can reduce the effect of this disease in high risks patients.
- Chronic Kidney Disease- Evidence suggests fish oil might be of some help to patients of CKD who are on dialysis treatment.
Treats diseases related to the respiratory system
- Asthma– Few early pieces of research show fish oils treat the symptoms of asthma by improving breathing functions and reducing the need for medications. Mothers who take fish oils during pregnancy reduce the risk of asthma in their children.
- Cystic Fibrosis- Oral intake of fish oils improves lung functions in children suffering from cystic fibrosis.
Other diseases where fish oil benefits can possibly be seen
Abnormal cholesterol (Dyslipidemia) – Cholesterol is carried in blood and it’s excess causes various metabolic diseases. Often abnormal cholesterol levels in blood cause artery clogging and related complications.
- HIV/AIDS medications are known to cause Dyslipidemia as a side effect. Since these medications cannot be discontinued, the alternative is to find a way to reduce the blood cholesterol and its effects. Fish oil reduces total triglycerides and total cholesterol. Thus helping people taking HIV/AIDS medications
- Following a kidney/ heart transplant, the blood levels of cholesterol are altered. This is potentially dangerous. Fish oil helps normalising the lipid profile in transplant patients
- Dyslipidemia caused by the drug Clozapine which isused to treat psychosis like schizophrenia is benefited by fish oils to some extent. Triglyceride levels are reduced but total cholesterol and LDL increases
Seasonal allergies/ hayfever- Mothers who take fish oils during the last trimester of pregnancy can lower the risk of allergies in their babies.
Chronic Fatigue Syndrome (CFS)- Some studies show that Efamol Marine, which is a combination of fish oils & evening primrose oil, reduces the symptoms of CFS.
Muscle soreness due to exercise- Research shows that daily oral intake of fish oil for 1-6 months, before and during exercise, reduces the muscle soreness from knee extension exercises.
Exercise performance- Evidence suggests fish oils increase lung capacity in athletes and thus overall performance. Although, no effect has been seen on endurance, heart rate and recovery rate.
Muscle Strength- Daily fish oil intake for 90-150 days along with 90 days of resistance training can improve muscle strength, especially in older women.
Pancreatitis- When fish oil is administered intravenously to the patients of pancreatitis along with parenteral nutrition, the need for kidney replacement therapy becomes meagre.
Phenylketonuria- Fish oil intake in children born with this genetic metabolic defect improves their vision, motor skills and coordination.
Bed sores( pressure ulcers)- Bed sores are a problematic complication to manage in people who are immobilised for long durations due to major operations, trauma, old age and coma. Early research shows supplementing IV fluids with fish oil slows the progression of such sores, giving them time to heal.
Sickle Cell Disease- Fish oil may reduce the pain crisis in people with sickle cell disease.
SLE (systemic lupus erythematosus)- Early studies show improvement in SLE symptoms on taking fish oil.
Risks associated with fish oil consumption
In low doses (3g per day or less), fish oils are usually safe. You should avoid high doses of fish oil unless medically supervised.
Fish oil side effects include
- Halitosis (bad breath)
- Heartburn / Gastritis
- Loose stools/diarrhea
- Allergic Rashes
- Epistaxis (nosebleed)
Some serious health concerns
- Bleeding- Fish oils affect the blood clotting system and interfere with drugs affecting blood viscosity. Avoid supplements if you have blood disorders or are taking blood thinning agents. The risk is also present in people with no documented history of blood disorders and people with liver disease. Stop fish oils at the first sign of bleed and consult a doctor immediately.
- Hypervitaminosis- Fish oils contain high levels of Vitamin A and D. Excess amounts of these are toxic to human body.
- Shellfish / Fish allergy- Those with these allergies will be at high risk of developing anaphylaxis/ allergic reactions to fish oil supplements.
- Ocean Pollutants- Mercury, pesticide residues, other industrial pollutants found in ocean fishes are biomagnified and are poisonous for us when consumed. One way to circumvent the problem is to buy only genuine and high-quality fish oil products, preferably with added antioxidants like
Eating contaminated fish or taking sub-standardised supplements may cause permanent neural damage, seizures, mental retardation & vision loss. The risk is higher in children.
Fish oil supplements like any other supplement meant for therapeutic purposes react with other drugs one takes. The two interact with each other and the results might be deleterious.
Persons taking any of the following drugs must consult their healthcare provider before starting fish oil supplements. Closely monitor for any symptom that might occur as a result.
- Anti-hypertensive medications (blood pressure lowering agents) like Captopril, Losartan, Diltiazem, Furosemide
- Oral contraceptive pills / Any hormonal medications
- Weight loss pills like Orlistat
- Anti-coagulants and Anti-platelet ( blood thinning agents) like Aspirin, Clopidogrel, Warfarin, Heparin
NSAIDs (Non-steroidal anti-inflammatory drugs) like Naproxen, Ibuprofen, Diclofenac.
Over to you on fish oil benefits
Omega-3 fatty acids are essential to normal growth and function of our body. Since they cannot be synthesised in our own body, care must be taken to actively include them in the diet like fish oil or other alternative sources.
According to the AHA (American Heart Association) (25), you must not take any supplement without proper doctor consultation. Eating fish is always a better way of consuming omega-3 than taking fish oil supplements.
AHA recommends salmon, tuna, Pollock, catfish, shrimps over larger predatory fishes like king mackerel, shark, catfish as these may have high mercury levels. So, show your heart some love and add fish to your diet.
Always consult with your healthcare provider before consuming any fish oil supplements. Inform him of your allergies, diseases, disorders and make an informed decision for yourself and your body.