Fish oils, such as trout, mackerel, tuna, herring, sardines, and salmon, come from fatty or oily fish. They contain fatty acids of omega 3, and vitamins A and D.
Fish-oil and omega-3 supplements are popular because they are thought to be beneficial for health. The American Heart Association ( AHA) recommends that oily fish should be eaten to promote heart health. Studies did produce mixed results, however.
A National Health Survey in 2012 found that about 7.8 percent of adults in the United States (U.S.), or 18.8 million individuals, and 1.1 percent of children aged 4 to 17, had taken a source of fish oil in the previous 30 days.
Important facts about fish oils
- Fish oils contain omega-3 fatty acids and vitamins A and D.
- Omega-3 fatty acids found in fish oils may protect the heart and offer other health benefits, but research results have been mixed.
- Eating fish is a better way of getting fish oil or omega 3 than taking supplements.
What are omega-3 fatty acids?
Omega-3 fatty acids are fats that are commonly present in plants and marine life.
Two types are plentiful in oily fish:
Eicosapentaenoic acid (EPA): EPA, the best known omega-3 fatty acid, helps the body synthesize blood clotting and inflammation chemicals (prostaglandin-3, thromboxane-2, and leukotriene-5). Fish obtain EPA from the algae that they eat.
Docosahexaenoic acid (DHA): In humans, this omega-3 fatty acid is a key component of sperm, retina, a part of the eye, and brain cortex.
DHA occurs throughout the body, especially in the brain, eyes and heart. It also occurs in breast milk.
Health benefits
Some studies have concluded that fish oil and omega-3 fatty acid have health benefits, but others do not. It has been linked to a number of conditions.
Multiple sclerosis
Due to its protective effects on the brain and the nervous system, fish oils are known to help people with multiple sclerosis (MS). At least one study, though, concluded they have no benefit.
Prostate cancer
One study found fish oils that reduce the risk of developing prostate cancer alongside a low-fat diet. But another study linked higher levels of omega-3 to an increased risk of aggressive prostate cancer.
Studies reported in the National Cancer Institute Journal indicated a high consumption of fish oil would raise the risk of high-grade prostate cancer by 71 percent, and all prostate cancers by 43 percent.
Post-partum depression
During pregnancy, the consumption of fish oils may reduce the risk of postpartum depression. Researchers advise that two or three times a week may be beneficial in eating fish with a high omega 3 levels. Rather than supplements, food sources are recommended, since they also provide protein and minerals.
Mental health benefits
An eight-week pilot study conducted in 2007 suggested that fish oils might help youth with behavioral problems, particularly those with attention deficit hyperactivity disorder (ADHD).
The study showed that children who consumed 8 to 16 grams ( g) of EPA and DHA per day showed significant improvements in their behaviour, as assessed by their parents and the psychiatrist who did work with them.
Memory benefits
According to research published in the journal PLoS One, omega-3 fatty acid intake can help boost the working memory of healthy young adults.
But another study showed that high omega-3 rates in older women do not prevent cognitive decline.
Heart and cardiovascular benefits
Omega-3 fatty acids found in fish oils can help protect the heart during mental stress times.
Findings published in the American Journal of Physiology indicated that in mentally stressful studies, people who took fish oil supplements for more than 1 month had improved cardiovascular function.
Researchers reported in 2012 that fish oil tends to help stabilise atherosclerotic lesions through its anti-inflammatory properties.
Meanwhile, a review of 20 studies involving nearly 70,000 people found “no compelling evidence” to link fish oil supplements to a lower risk of heart attack, stroke or early death.
In one study , people with stents in their hearts who took two blood-thinning drugs and omega-3 fatty acids were found to have a lower risk of heart attack relative to those who did not take fish oils.
The AHA recommends eating fish, and particularly oily fish, at least twice a week to reduce the risk of heart disease.
Alzheimer’s disease
It has been thought for many years that frequent consumption of fish oil can help prevent Alzheimer’s disease. Nevertheless, a major 2010 study found that fish oils were no better at preventing Alzheimer’s than a placebo.
Meanwhile, a 2007 study published in Neurology reported that the risk of dementia and Alzheimer’s was reduced by a diet high in fish, omega-3 oils, fruit , and vegetables.
Vision loss
Canadian researchers reported in the journal Investigative Ophthalmology & Visual Science that adequate dietary consumption of DHA protects humans against age-related vision loss.
Epilepsy
A 2014 study published in the Neurology, Neurosurgery & Psychiatry Journal claims that people with epilepsy may have fewer seizures if they consume low doses of omega-3 fish oil on a daily basis.
Schizophrenia and psychotic disorders
Omega-3 fatty acids contained in fish oil can help reduce the risk of psychosis.
Findings published in Nature Communications detail how a 12-week intervention with omega-3 supplements significantly reduced the risk of developing psychotic disorders over the long term.
Health fetal development
Consumption of omega-3 can help boost cognitive fetal development and motor development. In 2008, scientists found that consumption of omega-3 during the last 3 months of pregnancy may improve sensory, cognitive , and motor development.
Foods
Oily fish fillets contain up to 30% oil but this figure varies. White fish, like cod, contain high concentrations of oil in the liver but, overall, less oil. Rich in omega-3 fatty acids, oily fish include anchovies, herring, sardines, salmon, trout, and mackerel.
Other animal sources of omega-3 fatty acids are eggs, particularly those inscribed on the shell with “high in omega-3.”
Vegetable-based alternatives to omega 3 fish oil include:
- flax
- hempseed
- perilla oil
- spirulina
- walnuts
- chia seeds
- radish seeds, sprouted raw
- fresh basil
- leafy dark green vegetables, such as spinach
- dried tarragon
An individual eating a nutritious, balanced diet should not have to take supplements.
Risks
Taking fish oils, fish liver oils, and omega-3 supplements may present some people with a risk.
- Omega 3 supplements may affect blood clotting and interfere with drugs that target blood-clotting conditions.
- They can sometimes trigger side effects, normally minor gastrointestinal problems such as belching, indigestion, or diarrhea.
- Fish liver oils contain high levels of vitamins A and D. Too much of these can be poisonous.
- Those with a shellfish or fish allergy may be at risk if they consume fish oil supplements.
- Consuming high levels of oily fish also increases the chance of poisoning from pollutants in the
It is necessary to remember that the supplements consistency or purity is not regulated by the FDA. Buy from a reputable source, and take Omega 3 from a natural source whenever possible.
As low in mercury, the AHA recommend shrimp, light canned tuna, salmon, pollock, and catfish. They advise to avoid shark, swordfish , king mackerel, and tilefish, as they may be high in mercury;
It remains unclear whether consuming more fish oil and omega 3 will bring health benefits, but a diet that offers a variety of nutrients is likely to be healthful.
Anyone who thinks about supplements should check with a health care provider first.
