For thousands of years, the oceans of the Earth have provided humanity with a food source that has become a staple for millions worldwide: fish.
Thousands of species of edible fish are swimming out there, each providing a different taste, flavor, or texture depending on how they are prepared or served.
Many of these fish find their way to the tables of those who consume them for nourishment and subsistence and to the plates of food enthusiasts who fry, pickle, steam, boil, or even eat them raw.
Yes, they are good to eat! But as delicious as they are, the meat is just the icing for some edible fish. Some fish can offer more than immediate nourishment and pleasure to the palate; they can improve your overall health.
So what's in some of these fish besides their meat that's also good for humans? Their oil.
What is Fish Oil?
Fish oil is the oil derived from the tissue of oily fish. We call it fish oil, but the fish does not produce the oil itself. Their bodies store them but do not make them.
The fish get them by consuming either microalgae or prey fish that also have the oil. We only use fish as the source of the oil.
Types of Oil From Fish
There are several kinds of oil you can get from fish.
Shark Liver Oil
Many kinds of fish maintain buoyancy with swim bladders, but sharks are not among those kinds of fish. Instead of swim bladders, they have large livers full of oil.
Aside from maintaining buoyancy, the stored oil serves another function; as a nutrient store for when they have to go through long periods without eating or when food is scarce.
Deep-sea sharks are usually targeted for their oil because, unlike those species that are frequently sighted near the surface and inspire blockbuster suspense films, their livers can account for up to 5 to 10 percent of their total weight.
Cod Liver Oil
The oil from the liver of cod fish gained popularity as a dietary supplement after it was found to be high in vitamins A and D. Health experts recommend taking this oil during the winter months when you spend less time outdoors and in the sunshine.
However, it is not recommended for pregnant women or people with a high risk of liver problems or osteoporosis because of its high vitamin A content.
To extract this oil, cod livers are steamed and then pressed. The oil can be prepared both as a capsule or in liquid form.
The heating process is known to cause the loss of some vitamins; this is why others ferment the liver before processing them. This allows the separation of fat-soluble vitamins from the liver without damaging them.
You might wonder why the two abovementioned types are not considered fish oil. Their oil comes from sharks and codes, and sharks and codes are also fish. So they are technically oil from fish but not fish oil.
Unlike those oils mentioned above, fish oil comes from the flesh of the fish. So yes, you can also obtain fish oil from sharks and codes if you get it from their flesh. However, it will differ from the oil you can get from their liver.
What Makes Fish Oil Healthy?
Two types of Omega-3 fatty acids in fish oil have been proven to be healthy for humans; these are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)EPA
This essential fatty acid has been proven to be an effective treatment against inflammation.
The human body can convert alpha-linolenic acid (ALA, another essential fatty acid) to EPA. Eating foods rich in EPA is the best way to maintain sufficient levels, but our bodies also need to improve their conversion rate of ALA to EPA.
Aside from fish, this fatty acid is available to humans from some non-animal sources. While it's not usually found in higher plants, trace amounts of EPA have been found in purslane. In 2013, it was reported that a genetically modified form of the plant Camelina produced significant amounts of EPA.
If this sounds familiar, many infant milk formulas also tout having DHA for brain and body development. Fatty acids are believed to be good for the brain, considering that 60 percent of the brain is composed of fats.
DHA is a primary structural component of the brain, cerebral cortex, skin, and retina. Aside from being found in fish oil, it can be synthesized from alpha-linolenic acid and can also be found in breast milk or algae oil.
Most of the DHA in fish and multi-cellular organisms that regularly consume cold-water oceanic foods originates from photosynthetic and heterotrophic microalgae. The DHA becomes increasingly concentrated as it goes up the food chain.
DHA can also be manufactured from microalgae Crypthecodinium cohnii and another of the genus Schizochytrium. Companies specifically make them for vegetarians and vegans who would otherwise have no access to DHA.
Both EPA and DHA are types of Omega-3 fats. The number might make you wonder if other Omega-numbered fatty acids exist. Yes, there are, but they aren't derived from fish.
For instance, Omega-5 is a unique, essential fatty acid obtained from the pomegranate seed; it is also the only known botanical form of Conjugated Linolenic Acid or Punicic Acid. Omega-6 fatty acids come from poultry, eggs, nuts, cereals, durum wheat, whole-grain bread, most vegetable oils, and grape seed oil.
Omega-7 fatty acids are also formed from atoms at the end of the carbon chain. Sources of this acid include macadamia nut oil and sea buckthorn oil. The two most common Omega-7 fatty acids are palmitoleic acid and vaccenic acid.
EPA vs. DHA
Regarding these two, it's not a question of which fatty acid is better, but rather, what would be more appropriate for you during what stage in life.
Much like our diet, as we get older, our EPA and DHA requirements change. For instance, children require DHA for growth and body and brain development. Adequate DHA levels are recommended up until the age they start school.
From age five and up, the brain and central nervous system development starts to slow down, and so does the body's need for DHA. From here on, the body will need adequate levels of EPA.
EPA has been proven to help with behavior, attention, reduced aggression, and academic performance among children.
Among adults, EPA promotes the gene and cell cycle and regulates stress levels. An adequate supply of EPA can also help prevent various chronic illnesses.
Low EPA levels have been linked to mental health issues, including depression, dyslexia and dyspraxia, heart problems, and joint and bone conditions. Low levels are also linked to neurodegenerative diseases such as Multiple Sclerosis and Parkinson's.
Do you think you won't need DHA anymore? Think again.
At one stage in adult life, women will see the increased need for DHA again before, during, and after pregnancy. Pregnant women should get adequate DHA for the babies in their wombs and themselves.
This will be explained later in this article. For those in advanced age, high EPA levels are linked to a lowered risk of cognitive decline and dementia.
However, for those diagnosed already with Alzheimer's or dementia, DHA will become important again because this is needed for the structural support of the brain and to prevent further brain tissue loss.
EPA is also a precursor to DHA. This makes ensuring adequate EPA levels in a diet with neither EPA nor DHA a challenge because of the extra metabolic work required to synthesize EPA from ALA and the natural process that turns EPA into DHA.
For some people, medical conditions like diabetes or specific allergies may significantly limit the human body's capacity to metabolize ALA into EPA.
Best Fish to Get Fish Oil From
What fish are usually the sources of fish oil? You might be surprised.
Predatory fish with much fat, like sharks, swordfish, tilefish, and albacore tuna, are high in Omega-3 fatty acids. Still, because they are on top or close to the top of the food chain, they also tend to have many toxins and other harmful substances passed on to them from prey items they have ingested and those prey items ingested.
These toxins and contaminants include but are not limited to mercury, dioxin, polychlorinated biphenyls, and chlordane. On a side note, the United States Environmental Protection Agency also recommends limiting the consumption of the mentioned species, especially for women of childbearing age.
It's ideal for getting the fish oil from cold-water oily fish, such as salmon, herring, mackerel, anchovies, sardines, and other fish that aren't top or apex predators.
Did you know there is an even bigger market than human consumption regarding fish oil? The fish! Fish oil is used as a component in aquaculture feed, and over half of all fish oil harvested worldwide is fed to farmed salmon.
Fish Oil Benefits
These benefits fish oil is said to bring; some have been scientifically proven, while others still need further study.
People with attention deficit hyperactivity disorder tend to be hyperactive and may have trouble paying attention. We say "people" because this disorder isn't exclusive to kids; it can also affect teens and adults.
Where were we? Oh yes, according to DrAxe.com, a 2012 study involved children from 6 to 12 years old with ADHD who were being treated with methylphenidate and standard behavior therapy for over six months; after the parents reported no positive changes, the researchers gave some of the children an Omega-3 and Omega-6 supplement or a placebo.
They found "statistically significant improvement" in the group taking the Omega fatty acids regarding restlessness, aggressiveness, completing homework, and academic performance.
A separate study found that increasing Omega-3 intake, specifically DHA, may improve literacy and behavior in children with ADHD.
Improving the Immune System
Fish oil helps improve your immune system by reducing inflammation and improving your blood chemistry. In particular, DHA-rich fish oil enhances the activity of the B cell, a white blood cell essential to the immune system, and the production of antibodies.
When the antioxidant astaxanthin is combined with fish oil, the immune system's capacity is increased, according to a study of animals with similar immune systems to humans published in the Journal of Leukocyte Biology.
Salmon is a fish that naturally contains both fish oil and astaxanthin. There are also fish oil products that contain astaxanthin.
Sometimes the cause of your worries isn't the things that cause worries; in many cases, this can be because of hormonal or chemical imbalances in the body.
In 2013 the European Journal of Neuroscience published a study showing that fish oil reversed all anxiety-like and depression-like behavior changes induced in rats.
But that was rats! Where's the human proof?
Among people, it was found that populations that eat more fish tend to suffer less from anxiety. Epidemiological data and observational studies also show that a higher fish or DHA and EPA intake is directly associated with a lower incidence of depressive disorders in non-psychiatrically ill and psychiatrically ill populations.
It's good to start some people young. Some doctors recommend giving fish oil to children from early on and prevent them from developing anxiety or depression later on in life.
Preventing Alzheimer's Disease
While further study is required, the fact remains that for several years now, the direct connection between fish oil consumption and Alzheimer's disease prevention has been proven with consistent results.
The essential fatty acids in fish oil are vital to brain functions and help slow cognitive decline and prevent brain atrophy in older adults.
A study conducted by researchers at the Rhode Island Hospital established conclusive results when it sought to examine the relationship between fish oil supplementation and indicators of cognitive decline among older adults.
The study was conducted on 229 cognitively normal individuals, 397 patients with mild cognitive impairment, and 193 patients with Alzheimer's disease. Over a certain period, they were given brain magnetic resonance imaging every six months to check for brain atrophy as well as given neuropsychological tests.
Random samples of the test group were given fish oil supplements, while the rest were not. The study found that the adults who had not yet developed Alzheimer's and did not have genetic risk factors for developing Alzheimer's who took the fish oil experienced significantly less cognitive decline and brain shrinkage than the other test subjects who did not take fish oil.
Millions around the world suffer from this crippling disease. The sad this is they need not suffer from it with the proper treatment –fish oil.
An 18-month study published in 2014 showed the results of testing on three groups of people who suffered from rheumatoid arthritis; one group was given borage seed oil rich in GLA, another group was given fish oil, and the last group was a combination of both.
The test was to see how fish oil would measure up to borage seed oil, the usual remedy for rheumatoid arthritis. The results showed that fish oil was just as good as borage oil. No therapy outperformed the others, and the results were the same for the three groups after nine months.
Another study showed that fish oil supplements worked just as well to relieve arthritic pain as nonsteroidal anti-inflammatory drugs (NSAIDs). It is also a safer alternative to NSAIDs because it has none of its side effects.
When it comes to cancer, fish oil helps in two ways; first, it can kill cancer cells, and second, it can enhance the effectiveness of conventional anti-cancer drugs.
A scientific review was published in 2013 regarding the connection between Omega-3 fatty acids and prostate cancer prevention. Researchers found evidence suggesting that Omega-3s have antiproliferative effects on cancer cells, which inhibit cancer cell growth. It was also proven that Omega-3 fatty acids inhibited tumor growth.
Another study in India on the effects of fish on chemosensitize tumor cells found that using 5-Fluorouracil to treat colorectal cancer and fish oil increased the survival rate in carcinogen-treated animals. The same study also proved that fish oil relieved hematologic depression and gastrointestinal, hepatic, and renal toxicity caused by the anti-cancer drug.
Lastly, a scientific review published in 2014 sought to find the effects of Omega-3 intake on the prevention and treatment of breast cancer; it was found that EPA, DHA, and ALA can differentially inhibit breast tumor development. The study said there was sufficient evidence to recommend using Omega-3 acids to prevent and treat breast cancer.
Post-cardiovascular Disease Treatment
More conclusive and decisive studies have yet to prove that fish oil can prevent cardiovascular disease. Still, those studies are being conducted as many are trying to establish the link between fish oil consumption and lowered risk of this illness.
According to one such study conducted at the Cardiovascular Research Institute in Maastricht in the Netherlands, replacing fat with carbohydrates to prevent cardiovascular disease, long thought of as a solution to this problem, may do more harm than good. They also found that fatty acids have been observed to prevent the conditions leading up to cardiovascular disease.
What is certain, however, is that fish oil is suitable for those recovering from cardiovascular disease and those who have recently suffered from heart attacks.
One study into the effects of fish oil on heart attack survivors found that Omega-3 fatty acids from fish oil are associated with improved survival rates for heart attack victims.
Test subjects given a high dose of fish oil for six months following a heart attack were found to have improved their hearts' overall functioning. There was also proof of reduced systemic inflammation.
Lowering the Risk of Depression
This is another of those things that scientists want to prove definitively but have yet to be there.
But don't be depressed; a large study in Norway involving nearly 22,000 participants revealed that those who regularly consumed fish oil were about 30 percent less likely to have symptoms of depression than those who did not.
Other studies also found that people diagnosed with depression reported reduced intensity of anxiety, sleep disturbances, and sexual dysfunction when supplementing with fish oils.
According to the Mayo Clinic, fish oil should never be considered a replacement for treating depression. Still, it may be helpful as an addition to prescribed medications or other forms of treatment.
Consuming fish oil has been proven to help prevent diabetes and treat existing diabetic conditions.
According to WebMD, research suggests fish oil supplements could help reduce the risk of type 2 diabetes. Harvard researchers discovered that fish oils increase levels of a hormone called adiponectin linked to insulin sensitivity.
Another study found that fish oil can help reduce the risk of diabetics developing cognitive deficits by protecting the hippocampus cells from destruction.
Here's another eye-opener. According to a study, fish oil consumption can cut the risk of eye-diabetes complications.
The study was conducted on about 3,600 diabetic men and women between 55 and 80 years of age for nearly five years. The researchers found that people who regularly consumed 500 milligrams daily of Omega-3 fatty acids were 48 percent less likely to develop diabetic retinopathy than those who consumed less.
Preventing Eye Disorders
It's not just the diabetics who can benefit from fish oil helping prevent eye problems. Fish oil has been shown to reverse eye disorders that people usually develop as they age.
In 2009 the National Eye Institute released the results of a study that found age-related eye diseases and macular degeneration were lower by 30 percent in people who regularly consumed fish oil as part of their diet compared to others who didn't.
A higher intake of fish oil has also been linked to reduced cortical cataracts. Essential fatty acids also help drain intraocular fluid from the eye properly, lowering the risk of high eye pressure and glaucoma.
Improving Skin and Hair
Good news for the women; fish oil can make your hair look fabulous, and your skin looks smooth and feel supple. Who knew something so slimy could be so good for you?
Fish oil nourishes the skin with fats and contributes fat-soluble vitamins, giving it a smooth, elastic texture. Fish oil has also been proven to prevent wrinkles and signs of skin aging.
EPA and DHA deficiency has been linked to skin conditions, such as dandruff, eczema, psoriasis, age and sun spots, and thinning hair.
Without the essential fatty acids, too much moisture leaves the skin. Taking fish oil internally as a supplement may be as good as or even better than applying conventional moisturizers.
Another way fish oil can give you healthier skin is by reducing inflammation. Research shows that fish oil supplements can reduce sun-induced inflammation and relieve sunburn. Next time you go to the beach, have fish oil with you.
This goes for both men and women.
Recent studies show that fish oil consumption can improve fertility in men. DHA plays a vital role in the mobility of sperm and health of sperm in men.
In particular, DHA in fish oil is vital to changing dysfunctional round-headed sperm into strong swimmers with cone-shaped heads (like fish) packed with egg-opening proteins.
In women, fish oil has also been shown to increase fertility by reducing inflammation, balancing hormones, and regulating menstrual cycles. Fish oil has also been found to be effective in treating conditions that cause infertility, like polycystic ovarian syndrome and endometriosis.
Helping Normalize Pregnancy
We have already mentioned that DHA suits children and expectant mothers leading to delivery.
It's ideal for expectant mothers to have fish oils before, during, and after pregnancy. According to the American Pregnancy Association, most American women are deficient in EPA and especially DHA going into pregnancy.
This deficiency builds up during the pregnancy because the placenta supplies the fetus with DHA from the mother's tissue.
Omega-3 fatty acids also reduce the chance of premature delivery. EPA and DHA intake can help support healthy labor and delivery outcomes. Post-birth, these two fatty acids also help normalize the mood and overall well-being of the mother.
Aiding in Weight Loss
Strangely, it remains that sometimes eating some things is the best way to lose weight. Fish oil is one of those things.
In 2007, Australian researchers published the results of a study examining the combined effects of fish oil and exercise on weight loss. According to the study, combining fish oil supplements and regular exercise can reduce body fat while improving heart and metabolic health.
Two groups were studied; one was provided with fish oil in the diet, and the other wasn't. Over a certain period, the group taking fish oil registered lower triglycerides, increased HDL cholesterol, and improved blood flow.
Another study had test subjects undergoing a controlled diet for three weeks, where fish oil was served as a substitute for visible fats like butter and cream.
Researchers found out that their body fat mass decreased with the intake of fish oil, and the test subjects also registered a marked increase in physical activity. They concluded that dietary fish oil reduces body fat and stimulates the use of fatty acids to produce energy in healthy adults.
Types of Fish Oil Supplements
Since many of the ways we prepare fish cause it to lose its fish oil, manufacturers devised different ways to make it available to the public in its purest form.
This is also ideal for those who cannot eat fish because of specific allergies.
Fish Oil Foftgels
Soft gelatin capsules, or soft gels, make it easy to take liquid medications; the same applies to fish oil.
The problem with a fish oil regimen is taking the proper amount or dosage, and with soft gel capsules, this problem is eliminated.
Softgels also enhance the rate and efficiency with which the contents are absorbed by your body, according to a 2011 article in the International Journal of Pharmaceutical Sciences Review and Research.
The icing on the cake? Softgels are not so hard on the throat as tablets and not hard to swallow, thanks to their texture and overall lack of taste. This is particularly useful for people with a strong gag reflex.
The drawback? Softgel capsules can only contain so much when it comes to fish oil.
Liquid Fish Oil
If you take fish oil for its anti-inflammatory effects, you might have to take up to 10 or more soft gel capsules daily to develop the therapeutic dose. Fish oil in liquid form provides more Omega-3 fatty acids in a smaller serving than capsules can provide.
While they are assured of the correct dosage, some people need to know more about the taste of liquid fish oil. However, there is hope. A study proved that the older you get, the more and more the taste of fish oil becomes acceptable to the taste.
Emulsified Liquid Fish Oil
The emulsion process involves mixing fixed oil with another liquid to make it more acceptable to the human body. Emulsified fish oil is absorbed more quickly and efficiently, or so says a study published in the Journal of the American Dietetic Association in 2009.
This may be because the emulsification process breaks the fish oil into tiny droplets. This increases the surface area for any dosage or volume of oil ingested for digestion in the stomach and absorption in the small intestine.
The emulsification process also removes the fishy taste and "fishy burp" associated with fish oil supplements. Manufacturers can also add flavors to the fish oil to make ingesting them better.