Inferiority of Fish Oils
There is much conflicting information today regarding nutrition — and the consumption of fish oil versus plant-based oils is no exception.
Obtaining the already converted forms of omega-3 fatty acids from fish is said to be the best source.
Because of vested interests, half-truths, and almost exclusive testing on fish, fish oil has vaulted to the top of the omega-3 fatty acid charts.
However, more research is being done on plant-based oils, bringing to light information not previously known and showing why they will be the better sources in the future.
This section will provide some of the controversial problems that stem from consuming fish and fish oils as opposed to plant-based oils in order to obtain the valuable Essential Fatty Acids (EFAs).
Essential means that the body cannot make them; therefore, they must be consumed.
Fatty acids are the building blocks of the fat that our bodies need in order to function.
EFAs are:
- LA (linoleic acid) [Omega-6]
- ALA or LNA (alpha linolenic acid) [Omega-3]
Non-EFAs (non-essential fatty acids) include:
- EPA (eicosapentanoic acid) necessary for the circulation system
- DHA (docosahexanoic acid) necessary for the brain, heart, and eyes
- SDA (stearidonic acid) necessary to increase EPA concentrations
Non-essential because the body can make them from omega-3 ALA
- AA [ARA] (arachidonic acid) a necessary structural component and precursor that can have antagonistic effects
- GLA (gamma-linolenic acid) necessary to prevent certain skin conditions
Non-essential because the body can make them from omega-6 LA
Conversion Process
Omega-3 conversion process:
- ALA converts to the enzyme Delta-5-desaturase
- Delta-5-desaturase converts to SDA
- SDA elongates and converts to EPA
- EPA elongates and converts to DHA and the prostaglandin PGE3
(EPA is the precursor for series-3 prostaglandins and thromboxanes and series-5 leukotrienes)
Omega-6 conversion process is as follows:
- LA converts to the enzyme Delta-6-desaturase
- Delta-6-desaturase converts to GLA
- GLA converts to DGLA
- DGLA converts to the prostaglandin PGE1 and AA
- AA converts to the prostaglandin PGE2
Marine sources (oily fish and algae) contain the converted or long-chain forms of DHA and/or EPA.
Plant-based sources contain the parent (precursor) or medium-chain forms, ALA and LA. Land-based animals used to be good sources of these EFAs, which were concentrated in the brain, eyeballs, adrenal glands, and testes.
This explains one reason why primitive tribes prized these organs and ate them raw immediately after a kill.
Because of domestication, pollution, and feed, this is no longer the case.
In addition, through processing and refining of oilseed plants, all but scant amounts of the omega-3s (ALA) are lost, leaving only the omega-6 (LA) content.
Because there is too much LA in the average diet and too little ALA, health problems have skyrocketed.
ALA, omega-3, is found in such plant-based oils as:
- Chia seed (63.8%)
- Flaxseed (56.4%)
- Hemp seed (20%)
- Walnuts (3-14%)
- Soybean (6.8%)
- Pumpkin seed (0-15%)
Dark green leafy plants contain only a little oil, but what there is consists of over 50% ALA. Wild purslane is the richest green leafy plant source.
EPA and/or DHA are found almost exclusively in aquatic plants and oily fish. The highest levels come from salmon, tuna, sardines, trout, and corvina, but only if they eat phyto-plankton.
EPA and DHA supplements are also readily available, but the caution is that these two preformed EFAs are easily oxidized, thereby causing more health problems than they fix; adding an antioxidant, as vitamin E, will help to offset this problem to a certain extent – maybe.
SDA is found mainly in black current seed oil and is the biochemical precursor to EPA and DHA. While it has not been studied nearly as much as the other two, what has been done is to show health-benefit potential. SDA and GLA work together to alleviate various skin diseases.
LA, omega-6, is found in most oils, especially those from safflower, sunflower, hemp, soybean, walnut, pumpkin, sesame, and flax.
The richest source of LA is a non-processed safflower oil — which is hard to obtain. New genetic varieties of high oleic safflower and sunflower oils now contain only small quantities of LA, whereas before, they were once the richest sources.
GLA is said to be the only ‘good’ fatty acid form to come out of omega-6 fatty acid because it is almost identical to ALA.
The only difference between the two is where one double bond is placed on the chain. This may seem like a small difference; but to the body, it is a major distinguishing factor that impacts various functions.
Since there are many reasons why GLA cannot be converted from LA in the body, it is wise to obtain it from oils where it is already present.
Besides being formed from LA, GLA is also found in such oils as borage (20-26%), black currant (14-19%), evening primrose (7-10%), hemp seed (4% plus 2% SDA and 9% omega-9), as well as spirulina and walnuts.
AA is found only in animal fats and should not be confused with arachidic acid found in peanuts.
AA, as well as DHA, is crucial to the optimal development of the brain and eyes. Since these are non-essential fatty acids, the body can make AA from LA and DHA from ALA.
Below, are some reasons why fish oil is inferior to plant-based oils.
Reason 1 – Fish is no longer a health food.
Today, it is widely recommended that people obtain their EFAs from fish. For vegans and some vegetarians, this is not an option.
Among the main problems with this advice is that all marine life has varying levels of toxins and pollutants. One of the nastiest is a class of contaminants called POPs (Persistent Organic Pollutants).
This category consists mainly of dioxin, PCBs (polychlorinated biphenyls), and DDT. These cause a host of health problems, including reproductive difficulties, cancers, and neurological disorders.
Those most at risk are ones with weakened immune systems (which include a good portion of the so-called healthy population), children, pregnant women, and the elderly.
Dioxins and PCBs are two of the most dangerous chemicals known to man because, not only are they toxic, persistent, and bio-accumulative, but they can also be carried long distances in air currents, thereby posing a threat to humans and wildlife living in remote places once thought to be safe.
Because they are also fat soluble, oily fish and fish oil supplements can be rich sources of POPs.
These toxic chemicals, along with heavy metals, are especially concentrated in the livers of fish – an important fact to consider if taking fish liver oil supplements.
It is no secret now that people who regularly consume fish will have larger levels of toxic chemicals in their bodies than those who eat fish only occasionally or who do not consume it at all.
Another chemical of concern is mercury. Although it occurs naturally in the environment, most is released by incineration and coal-burning power plants and by mining and industrial processes.
In the US alone, more than 40 tons of mercury are released into the air every year, eventually ending up in water where it changes into a form called methyl mercury, which accumulates in fish as they grow older and bigger.
Fish that tend to have high levels of POPs in their bodies, are also ones more susceptible to accumulations of mercury.
Women in coastal areas have higher levels of mercury than those who live inland.
Ironically, pregnant women are told to eat more fish to obtain valuable omega-3 fatty acids for their unborn child. By doing this, however, they are exposing greater risk to their unborn children.
Fetal exposure to mercury can cause learning deficits and other neurological problems. This is not an isolated problem occurring in the far north. It is estimated that a full 10% of American women (about 7 million) have mercury levels above what is considered to be average. Despite these findings, fish is still being recommended – but in smaller doses.
Significant amounts of EFAs are found only in ocean fish that have eaten plankton rich in ALA. This does not apply to farmed fish, which are fed various high protein concentrates.
According to Professor Frank Hu, who conducted a 16-year study on omega-3 fatty acids and heart disease in women, farmed fish hardly contains any omega-3 at all.
In addition, because of pollutants, some researchers advise that consuming more than one meal of farmed fish every month or two increases the risk of cancer.
As if that wasn’t bad enough, farmed fish may also contain flame retardants (Science Daily). Although these have been found mainly in cod liver oil, farmed fish (including European salmon) that are given feed containing liver oils are more likely to have PBDEs (polybrominated diphenyl ethers).
PBDEs are showing up in a wide variety of unusual places such as human breast milk in the United States and peregrine falcon eggs in Sweden.
Fish oils are also used as feed supplements for farm animals, including sheep, cows, and chickens.
Additional studies have shown a paradox concerning the elderly who are encouraged to eat fish.
Research found that, while an increased consumption of fish was associated with a decreased risk of late age-related maculopathy (ARM), it also interfered with the absorption of vitamin E (a potent antioxidant) and one very necessary in reducing risk of several disorders, including visual disturbances.
To be sure, contaminants are also found in plant foods. See the Environmental Working Group Listings
This is why it is so important to obtain organic foods whenever possible. While organic produce may not be available in all areas, it does present reason enough for people to make every effort to have them grown in their communities and brought into their stores. Until then, consume more foods that contain the least amount of contaminants.
Aside from contaminants, fish is being recognized as a major food and occupational allergen.
Reactions to fish are among the most common food allergies found in adults and children. But fish is not always obvious. Fish can be found in such items as Worcestershire sauce, which may contain anchovies, Caesar salad, and imitation seafood.
Reason 2 – Not all fish oils are created equal.
The main, and most popular, source of DHA and EPA is said to be fish oil. However, not all fish oils are good sources of these fatty acids.
The highest levels come from salmon, tuna, sardines, trout, and corvina, but many fish oil supplements contain only oils from one of these (sardines).
The rest is made up of the oils from such cheaper and lesser fish as mackerel and anchovies. Some manufacturers state it is because they are lower in pollutants, but pollutants are found in all oily fish.
Fish oil for supplements comes mainly from reduction fisheries in Peru and Chile. Europe, Africa, and the US make up the rest of the market. Fish caught for reduction are mainly anchovies, sardines, mackerel, and menhaden used specifically for fish oil, fishmeal, and animal feed.
Fish oil supplements can come in several forms: natural or chemically modified and can be stable or unstable.
Natural fish oils have a maximum concentration of 38%. Anything higher than that has been chemically modified and come in three different types: those containing triglycerides where the fatty acids have been chemically changed; those that contain ethyl esters; and those that have free fatty acids.
Natural fish oil has the balance of all the fatty acids in the fish. Although chemically modified supplements may have higher concentrations of DHA and EPA, they have not proven themselves to be more effective.
Obtaining DHA and EPA from canned fish is not a good alternative either.
While canned fish is said to contain some EFAs, much is lost in the extensive processing. In addition, the natural fish oil, where the essential fatty acids are located, is removed through pre-cooking and replaced by cheaper hydrogenated vegetable oils, usually from olives, sunflower, or soy.
As we saw in Reason #1, canned fish also contains pollutants, including mercury as well as other substances not on the label, but allowed by governmental regulations.
Another problem not readily seen is the amount of canned fish one would have to eat to obtain the necessary DHA and EPA content.
For example, the EPA/DHA content of a 3 g serving of tuna (packed in water) is roughly 0.24 percent. To fulfil the recommended one gram daily requirement, one would have to eat 12 more of these.
Also previously mentioned, farmed fish contain hardly any omega-3 fatty acids unless they are fed significant amounts of fish scraps. Since most are fed vegetable proteins, the valuable omega-3 content will be next to nil compared to ocean fish that feed on plankton. Interestingly, plankton found in colder waters contains more omega-3s than that found in warmer waters.
Hydrogenated or partially hydrogenated fish oil is popular in such countries as Holland, Norway, Great Britain, Chile, Peru, and South Africa. These are not only a source of the harmful trans-fats, but also a poor source of the omega-3 fatty acids, mainly because the hydrogenation process that all but eliminates any EPA and DHA content.
A report published by ConsumerLab found that, of the 41 brands of Omega-3 fatty acid fish oil supplements tested, none had detectable levels of mercury; that is, less than 1.5 parts per billion (ppb) and no unsafe levels of PCBs (polychlorinated biphenyls) – what is deemed a “safe” level is not determined since the definition fluctuates among organizations.
For example, the biggest gap is with PCB levels. Not surprisingly, FDA standards are the least stringent (2,000 parts per billion (ppb) while the State of California has the most stringent standard (90 ppb).
The report goes on to say that one brand of fish oil supplement was spoiled and some fell short of the amount of EPA or DHA stated on the label with the worst containing only 53% of its claimed EPA content. Although this product was marketed for use by pets, it was also sold for human consumption.
Another study was done by a group called Environmental Defense. They contacted 75 companies who produce fish oil supplements commonly found in supermarkets, pharmacies, and health food stores and asked them three questions.
- Do you purify your fish oil to reduce or remove environmental contaminants?
- What methods do you use to purify your fish oil?
- What standards do you comply with regarding acceptable levels of contaminants?
Environmental Defense also requested information on three contaminants: mercury, PCBs, and dioxins since these three are found in the majority of consumption advisories for fish caught in the United States.
Although most companies adhered to a strict standard of contaminant removal, some were less than forthcoming with their information. Therefore, consumers are admonished to be knowledgeable about the brands they are using – and not just with fish oil supplements.
Pharmaceutical grade fish oil is a term used to separate unscrupulous fish oil supplement manufacturers from those trying to offer a decent product. However, since there are no set standards for this term, it didn’t take long before it was picked up and widely used.
To some, pharmaceutical grade means a concentrated potency of EPA and DHA in their products, while to others it means a lack of impurities and contaminants.
Most fish oil supplements found in grocery or drug stores apparently do not even meet the standards of this open-ended definition.
According to some manufacturers, it takes roughly 100 gallons of health-food grade fish oil to produce one gallon of pharmaceutical-grade fish oil.
But even this is not set in stone. It just depends on the ethics of any particular manufacturer.
Dr. Barry Sears, who supposedly was the first to coin the term pharmaceutical-grade, has become so disgusted with it all, that he changed the name of his pharmaceutical-grade product to ultra-refined.
According to a consumer report by International Fish Oil Standards, standards of quality have been raised to a 5-star rating system that will show better levels of quality and purity. Although this particular report lists various products that meet their “consumer ready” standards, nothing was stated as to whether any or all received the full 5-star rating.
To be fair, it is these products that try to maintain high quality standards.
Reason 3 – EFAs are easily destroyed, especially preformed ones.
Essential fatty acids, especially omega-3s, are easily destroyed by light, oxygen, heat, metals, and time.
Light can induce free-radical chain reactions that break down EFAs into aldehydes, ketones, and other toxic and nontoxic products, as well as destroying their vital properties. Light destroys the EFAs in oil 1,000 times faster than does oxygen and is the reason that cold-pressed oils are sold in dark bottles.
Oxygen causes EFAs to become rancid, resulting in a scratchy, bitter, or fishy taste and smell. Rancid fats are linked to increased rates of cancer, heart disease, atherosclerosis, and various other health problems.
Heat destroys EFAs by twisting the molecule into an unnatural shape, thereby producing harmful free radicals and other toxic substances.
Metals, for example, nickel and aluminum are catalysts used in the hydrogenation process.
Time is also a destroying factor. As soon as a fish dies, its components begin to deteriorate immediately. The same holds true for oil seeds and grains. This deterioration accelerates during storage and processing, even when stabilizers are added. The major sign of deterioration is rancidity, as evidenced by a ‘fishy’ or off-taste that leaves a scratchy feeling in the back of your throat. One exception may be chia seed, which does not lose its naturally occurring antioxidants (chlorogenic and caffeic acids). It appears this is the reason that the ancients were able to keep the seeds for long periods of time without spoilage.
With this in mind, when fish is cooked or canned, almost all of the nutritional benefit is lost and may even turn around to be more harmful. In fact, EFAs in fish oils are destroyed five times more rapidly than the seed oil component, ALA; and ALA is five times more sensitive than LA.
Adding insult to injury, while the much sought-after long-chain (preformed) EPA and DHA are destroyed by cooking, toxins are not. Therefore, because of toxins and parasites, eating fish raw should never be an option.
Destruction through oxidation is a crucial factor when dealing with EPA and DHA supplements. While ALA is a fairly stable compound, the converted forms are not, thereby dramatically increasing the formation of free radicals.
There is a close relationship between peroxidation (a free radical attack on cells) and cardiovascular diseases as well as such other diseases as cancer, cataracts, immune system decline, and brain dysfunction.
Studies have shown that the risk of CHD (coronary heart disease) is indeed reduced by the effects of EPA and DHA but only if there is sufficient oxidative protection to minimize both the lipid peroxidation and the disruption of the cell’s antioxidant system.
This is why many manufacturers of fish oil supplements include the antioxidant, vitamin E (alpha-tocopherol) – not only to prevent oxidation but also to maintain EPA/DHA stability after it is consumed.
However, this small amount of vitamin E does not offer sufficient protection. The vitamin E used is usually the cheaper synthetic form and added only to increase shelf life. It has nothing to do with the health of the recipient. Potency of synthetic vitamin E is well recognized as being half that of the natural.
Vitamin E supplementation is very important if consuming fish or taking fish oil; which will be dealt with in Reason #4.
Reason 4 – Fish-based EFAs increase certain risks.
Studies have found that there is a significant reduction of vitamin E in the liver and plasma when DHA is taken without vitamin E supplementation. Not only is there is a close relationship between peroxidation and cardiovascular diseases, but also other diseases including cancers, cataracts, immune system decline, and brain dysfunction.
Therefore, those who take fish oil supplements or whose diets are high in fish are strongly advised to take added vitamin E supplements.
This is the main advantage to consuming ALA rather than DHA and EPA from fish. Even high intakes of ALA from plant-based oils do not cause a vitamin E deficiency, but fish oil and other DHA and EPA supplements can.
The formation and progression of atherosclerosis have been directly linked to lipid peroxidation (the deterioration of the EFAs that cause trans fats). When DHA was used to decrease this risk, DHA was transformed into a promoter of the disease when there was not enough antioxidants present.
Some researchers are expressing concern that fish oil supplements appear to depress the immune system’s response to infection. Moderate to high intakes of EPA – but not of ALA – can decrease natural killer (NK) cell activity in healthy subjects.
Natural killer cells play an important role in defending the body against viral infections.
Researchers at Tufts University Human Nutrition Center have determined that fish oil reduces the production of T-cells and other lymphocytes by at least 63 percent, and actually use this method to create vitamin E deficiencies in their experiments.
Another risk factor is aimed at those taking anticoagulants (blood thinners), especially aspirin, warfarin, dalteparin, and enoxaparin.
Fish oil tends to intensify blood-thinning effects; and these patients are at a greater risk for bleeding episodes, including internal bleeding. While blood-thinners help prevent heart attacks, they can increase the risk of hemorrhagic stroke. Therefore, those on anticoagulants and those with high blood pressure are advised not to take fish oil supplements.
Diabetics are at greater risk for heart disease and are now being advised not to use fish oil supplements. Although studies have shown that the supplements lower triglyceride levels, fish oil supplements tend to increase LDL cholesterol, often referred to as the ‘bad’ cholesterol. The increase was significant, especially in those taking the highest doses.
Consuming fish oil (or vitamin E) also does not prevent secondary coronary heart disease (subsequent episodes following non-fatal heart attacks or strokes). Researchers did admit that important questions still remain about the benefits of plant sources of EFAs, but they were definite about the promotion of fish oil capsules for the prevention of further episodes.
Reason 5 – The hype about ALA conversion contains half-truths.
Claims that the human body cannot convert ALA into EPA and DHA in sufficient quantities to do any good is one of those half-truths that vested interests love to exploit.
Humans, from fetus to old-age, are able to convert ALA to DHA, a process observed in other species as well. Even vegetarians do not suffer if their diets contain no additional DHA in their diets.
Make no mistake, DHA (along with AA) is very important to the body: for brain function and development, vision, sperm counts, protection of the heart, and for anti-inflammatory action. In fact, DHA is the most abundant EFA in the brain, mother’s milk, and the eyes.
EFA must be converted from ALA, otherwise life would literally cease to exist but that part is rarely mentioned.
Instead, the trend today is to promote a fear that people must get their DHA from fish. If that were truly the case, people walking around without benefit of fish oil supplements or even access to fish and who are only able to rely on plant-based oils would be dead or very close to it.
Since DHA remains in the body for only about a week, humans are converting what they need, when they need it. Some people convert more slowly while others do so rapidly. Women possess a greater capacity to convert ALA than men, no doubt to compensate for pregnancy.
One small study showed that the women involved were able to convert an average of 36% of the ALA they were given into long chain derivatives (21% EPA, 6% DPA, and 9% DHA).
Another small study with men, showed that they converted an average of 16% of the ALA they received into long-chain derivatives (8% EPA and 8% DPA but no DHA) – although another study did show that men do convert ALA to DHA just as well.
Research has also proven that as quantities of dietary DHA increased, synthesis of DHA from ALA decreased but was not totally suppressed, even when the DHA levels are increased to very high concentrations.
This means that the natural ability to convert ALA to DHA diminishes as more supplemental DHA is taken in but does not stop entirely.
Studies conducted in Japan confirmed these findings. Ten months of feeding ALA to elderly volunteers (ages 67-91) showed serum increases of DHA. This surprised researchers since the regular intake of long-chain omega-3s from fish had been very high. The conclusion was that DHA synthesis from ALA is a continuing process and the body adjusts to fulfill essential brain functions.
The following is but one example that gives a suitable amount of EFAs one should consume while also taking into account the currently accepted conversion rate of 1% ALA to DHA.
- One tablespoon of hempseed oil or 1 ounce of shelled hempseed per day supplies roughly 6.6 grams of omega-6 and 2.2 grams of omega-3s, which is the right amount required for a 2000-calorie diet.
Why not flaxseed?
Flaxseed has an overabundance of omega-3s, which is good for a short-term treatment of an omega-3 deficiency.
For long-term health maintenance, however, hemp seed or chia seeds are better alternatives because they are the closest to the ratio the human body demands – which is roughly 3:1 (omega-6 to omega-3).
Hemp seed and chia seed have this ratio. Flaxseed has an opposite ratio of 1:3.
In addition, flaxseed cannot be digested unless it is ground up, which increases the risk of oxidization. This is also true of hemp seed and the reason why both seeds need to be refrigerated.
Chia seed, however, does not have this problem as it contains natural antioxidants that keep it from spoiling.
When using plant-based oils, conversion rates increase when other nutrients are present. Although recommendations vary as to which nutrients, most agree that these are necessary to help increase the conversion of ALA to its necessary derivatives: zinc, selenium, magnesium, folic acid, and vitamins B3 (niacin), B6 and C.
Researchers have compared the effects of supplying ALA of vegetable origin with marine sources of DHA and EPA. They determined that there was very little differences between the two as far as effect on humans were concerned.
However, it has been found that vegetable oils containing SDA (hempseed, black currant seed, and echium oils) could be more effective in increasing tissue EPA concentrations than the currently ALA-containing vegetable oils.
Medium-chain fatty acids from plant-based oils are more easily digested than long-chain fatty acids from fish, for example.
When long-chain fatty acids are eaten, they must be emulsified by bile salts in the small intestine before they can be absorbed into the body.
Short- and medium-chain fatty acids are absorbed directly through the portal vein to the liver, where they are immediately available to the body.
Medium chain fatty acids also help increase the absorption of such nutrients as the fat-soluble vitamins A, E, D, and K as well as magnesium, calcium, carotenoids, flavonoids, and the supplemental long-chain fatty acids EPA, DHA, and GLA.
It seems obvious that adding fish oil to an already bad diet is not the answer for preventing disease. A good diet, complete with vital nutrients, is the overall answer as well as the more immediate solution that requires the conversion of parent essential fatty acids into the components the body requires on a daily basis.
Reason 6 – Fish oil and EPA may not be best for the heart.
Fish for the heart first gained popularity in 1969 when two Danish physicians determined that the Eskimo population in Greenland had a much lower death rate from heart disease than the rest of the Danish population. They concluded that the reason for this had to be the high consumption of fish.
Since then, fish has been studied to death!
As a result of all these intense fish studies, it has been the common belief that EPA was best for the heart while DHA was best for the brain.
For many years, it was believed that the main benefits of fish oils for the heart came from EPA because of its role in modulating eicosanoids (a class of cytokines which have hormone-like actions that increase LDL or ‘bad’ cholesterol levels). Because of this, typical omega-3 fish oil products contain higher concentrations of EPA than DHA.
However, new research is showing that DHA offers greater cardiovascular benefits than EPA.
DHA regulates healthy blood pressure whereas the same amount of EPA cannot. In addition, DHA boosts the ‘good’ HDL cholesterol while lowering the ‘bad’ LDL triglycerides, something also associated with insulin resistance.
One interesting study out of Finland showed that, although DHA and not EPA was instrumental in the considerable lowering of the risk factor for CHD, consuming that amount of fish also dramatically increased the mercury content in their bodies.
Another study, involved Mediterranean men with CHD who had significantly lower omega-3s in their blood than other men free of the disease. The difference was found to be DHA (and DPA) but not EPA.
The reasons behind DHA being more effective than EPA are attributed to its functions. DHA is vital in preventing arrhythmias, regulating blood pressure, and for boosting the ‘good’ HDL cholesterol.
A low HDL level is not only linked to heart disease and metabolic syndrome X (a group of risk factors that determine if one is prone to heart disease), but is also associated with insulin resistance – and diabetics are known to be at a higher risk for CHD.
Because of its preformed omega-3 fatty acids, fish oil is often taken to reduce cholesterol; but fish oil contains cholesterol because it is an animal product. Amounts vary, however.
For instance, 100 grams of sardine oil contains about 710 mg. cholesterol, salmon oil – 485 mg, menhaden oil – 521 mg, herring oil – 766 mg, cod liver oil – 570 mg, and trout meat contains 58 mg.
For some people, taking large amounts of fish oil may be effective in lowering triglyceride levels but, for others, fish oil increased LDL levels.For these people, it took the addition of 15 grams of pectin per day and garlic supplementation to lower the LDL levels.
Usually any triglyceride-lowering effect can be attributed to replacing meat and other saturated fatty sources with fish. The same thing would happen if these saturated fatty sources were replaced with beans or other vegetable proteins. Plant-based oils, on the other hand, contain no cholesterol (another half-truth that is often seen on labels).
Fish oil simply is not needed to reduce the risk of heart disease, which has been noticed in the vegetarian community. Diet and the use of plant-based oils have long proven to be more effective in the long run.
Although one study recommended fish (with a note of caution because of such pollutants as mercury), it did state that for vegetarians or non-fish eaters, a total daily intake of 1.5 to 3 g per day of ALA seemed to be beneficial.
As confirmation, a flurry of controlled studies determined that consumption of ALA omega-3 fatty acids, rather than fish oil, is associated with the reduced risk of CHD (coronary heart disease).
Furthermore, one study went so far as to suggest that the percentage of DHA in erythrocytes could be used as an indicator of risk for CHD since it is DHA and not EPA that raises HDL cholesterol levels.
One study to watch for is currently being carried out at the St. Boniface General Hospital Research Centre in Winnipeg, Canada.
One of their projects includes the effects of fish oil, flaxseed oil, and hempseed oil supplementation on plasma lipids, LDL oxidation, inflammatory profile, and platelet function in healthy humans.