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All fats, including saturated fatty acids, play important roles in the body (1). However, the most important fats are those that the body cannot make itself and thus must come from the food we eat.
These are called essential fatty acids (EFAs).
The Discovery of Essential Fatty Acids
Dietary fat was only recognized as a valuable source of energy and fat-soluble vitamins in the first part of the 20th century. However, fatty acids were not considered to be essential nutrients because it was assumed that they could be synthesized from dietary carbohydrates.
This well-established belief was challenged in 1929 by George and Mildred Burr who reported that dietary fatty acid was required to prevent a deficiency disease that occurred in rats fed a fat-free diet. This was a hugely important finding and is considered to be one of the landmark discoveries within lipid research (2).
Types of Essential Fatty Acids
EFAs can be divided into two groups: the linoleic acid (omega-6 group) and alpha-linolenic acid (omega-3 group).
We need both groups of essential fatty acids in order to be healthy. However, due to the diets that we tend to consume, we tend to have a disproportionately high intake of omega-6 fatty acids compared to omega 3-fatty acids (3).
Studies have demonstrated that increasing the intake of certain essential fatty acids, either alone or with other compounds, can improve both mental and physical health status.
Omega-6 Fatty Acids
There are four types of omega-6 fatty acids: linoleic acid (LA), arachidonic acid (ARA), gamma-linoleic acid (GLA) and conjugated linoleic acid (CLA).
Omega 6-fatty acids are a type of polyunsaturated fat and are found in soybeans, vegetable oils, nuts, and seeds.
Omega-6 fats play a key role in regulating genes, maintaining immune health and promoting blood clotting.
Omega-3 Fatty Acids
The three main types of omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).
ALA is known as a short-chain fatty acid, whereas EPA and DHA are long-chain fatty acids. ALA is found predominantly in plant oils such as flaxseed, soybean, and canola oils.
DHA and EPA tend to be found in algae, fish and other seafood.
Omega-6 fats play a key role in regulating genes, maintaining immune health and promoting blood clotting. These fats can also help with the symptoms of rheumatoid arthritis and dermatitis.
Although the body can convert some ALA into EPA and then to DHA, this can only occur in very small amounts because the conversion efficiency is very poor. Therefore, getting EPA and DHA from foods and dietary supplements is the only practical way to increase the levels of these omega-3 fatty acids.
7 Best Supplement Sources of Essential Fatty Acids
In addition to obtaining essential fatty acids through your diet, there are also a number of nutritional supplements that can boost your intake.
Krill oil is derived from krill, a member of the crustacean family. It contains two of the same fatty acids as fish oil, EPA and DHA, in the form of phospholipids, mainly phosphatidylcholine. This improves its bioavailability, which means that it is easier than fish oil for the body to absorb.
How does krill oil boost health?
Krill oil has been shown to be effective in reducing inflammation and the symptoms of rheumatoid arthritis.
One randomized, double-blind, placebo-controlled study found that 30 days of daily supplementation with 300mg Krill oil significantly reduced symptoms of rheumatoid arthritis (6).
There was a 20.3-28.9% symptom reduction as assessed by the Western Ontario and McMaster Universities (WOMAC) osteoarthritis score and 31.6% less rescue medication usage. Positive results were seen after 7 days of supplementation, in terms of reduced pain, stiffness and functional impairment.
Improvements in heart health have also been observed from krill oil supplementation.
A multi-center, three-month, prospective, randomized study found that a dose of between 1 g and 1.5 g krill oil daily was effective in reducing glucose, total cholesterol, triglycerides, LDL, and HDL, compared to both fish oil and placebo (7).
How do I take krill oil?
Supplementation of Krill oil tends to be in the range of 1-3g daily, which is the dose that has been used in the clinical trials.
Due to the higher bioavailability, the omega-3 content from a krill oil supplement should be equivalent to approximately 2/3 of the usual amount taken of fish oil.
For example, if you would usually supplement with 1000mg of fish oil, 660mg of krill oil would be sufficient to obtain the same amount of omega 3.
Fish oil is a source of the two omega-3 fatty acids EPA and DHA. These fats are can also be found in fish, animal products, and phytoplankton.
Fish oil refers to a mixture of fatty acids where the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are dominant.
Fish is the most common source for fish oil, hence the name, but any artificially manufactured EPA/DHA dominant mixture from any source could technically be considered fish oil.
How does fish oil boost health?
Fish oil has been found to boost heart health, by reducing triglyceride levels and low-density lipoprotein (LDL).
A meta-analysis of randomized placebo-controlled trials investigated the effect of monotherapy with EPA, DHA or EPA vs DHA (8). Compared with placebo, DHA was found to raise LDL 7.23 mg/dL whereas EPA non-significantly reduced LDL.
In studies directly comparing EPA and DHA, DHA raised LDL 4.63 mg/dL more than EPA. Although both EPA and DHA reduced triglycerides, DHA had a greater effect than EPA in direct comparison studies. DHA also raised high-density lipoprotein compared with placebo, whereas EPA did not. Although EPA and DHA both reduce triglycerides, they seem to have different effects of LDL and HDL.
A meta-analysis found that fish oil significantly reduced arterial stiffness, a risk factor for heart disease (9). Results were not influenced by changes in blood pressure or heart rate.
Fish oil has also been found to reduce the symptoms of depression. A 4-week, parallel-group, double-blind addition of either placebo or EPA to ongoing antidepressant therapy was found to lower depression rating scores by a mean reduction of 12.4, while placebo only resulted in a reduction of 1.6 based on the Hamilton Rating Scale for Depression (HRSD) (10).
One randomized control trial looked to determine the most effective dose of EPA by comparing 1, 2, and 4 grams per day to placebo (11). The highest response rate was found for those taking 1g per day, suggesting that this is the optimal dose and that higher doses do not provide greater benefits.
Fish oil can also reduce high blood pressure. A randomized, prospective, double-blind, controlled study found that 5g fish oil per day reduced blood pressure and triglycerides compared to the same amount of safflower oil (12). There was also a small reduction in total cholesterol and blood glucose levels.
Fish oil can help to improve lupus symptoms. A double-blind, double placebo-controlled factorial trial found that 3g of EPA taken daily for 24 weeks in those suffering from lupus reduced symptoms as assessed by the SLAM-R rating scale (13).
How do I take fish oil?
Fish oil doses vary according to the goal of supplementation. For general health, 250mg of combined EPA and DHA is the minimum dose to obtain benefits.
However, the American Heart Association recommends 1g daily and this is the dose most commonly used in studies.
Because fish oil is a combination of two different fatty acids, EPA and DHA, these numbers reflect a combined total. It can be taken throughout the day but to avoid the “fish burp” taste, it is best to take fish oil with meals.
Safflower oil comes from the seeds of the safflower plant and is often used for cooking.
It is found in two main forms: high linoleic acid (up to 75%) and high oleic acid (up to 75%), both of which are unsaturated fatty acids. It is particularly high in conjugated linoleic acid (CLA).
How does safflower oil boost health?
Safflower oil has been shown to be beneficial for managing blood glucose levels.
A blinded comparison study of 8g safflower oil vs 8g of CLA found that safflower oil provided benefits to blood glucose metabolism over 12-16 weeks (14). Total blood glucose levels were also reduced, as measured by HbA1c levels.
Other benefits to lipid metabolism were found from supplementation with safflower oil, including an increase in HDL-C by 0.1+/-0.1mmol/L. A reduction in inflammation was also found, as indicated by a reduction in C-Reactive Protein (CRP) by 3.4+/-9.9mg/L.
Safflower oil has also been found to increase lean muscle mass.
A 36 week randomized, double-masked, crossover study found that 8g of safflower oil taken daily was able to significantly increase muscle mass compared with taking the same amount of CLA (15).
This was assessed by DEXA scan, considered to be the “gold standard” for measuring body composition.
How do I take safflower oil?
To obtain the health benefits of safflower oil, it is recommended to take 8g daily. This can be taken in one dose or split into smaller doses.
It can be taken at any time of the day, with or without food.
Algae are marine-based photosynthesizing organisms. This means that they live in the water and obtain energy from sunlight.
They share some features with land-based plants but don’t have leaves or roots so they are considered to be a different family of plants.
In addition to containing omega-3 fatty acids in the form of EPA and DHA, they also phytochemicals such as chlorophyll, and minerals such as iodine, all of which are beneficial for health.
Algae are the base of the food chain for fish, which means that fish consume them and therefore have high amounts of EPA and DHA in their tissues. Algal oil is, therefore, a useful source of omega-3 fatty acids for vegetarians and vegans.
How does algae oil boost health?
Research has shown that algal oil is beneficial for heart health.
A meta-analysis of 11 randomized controlled trials found that a daily dose of around 1.68g significantly reduced triglyceride levels and increased HDL cholesterol levels (16).
These are similar to the results found with fish oil, demonstrating that algal oil is a suitable alternative for those not wanting to consume fish.
Another study confirmed these equivalent benefits. It was shown that algal oil can raise EPA and DHA levels in the body similarly to fish oil (17).
The results demonstrate that algal-oil supplements are a sufficient and viable source of DHA for fish and non-fish eaters alike.
How do I take algal oil?
Research demonstrates that taking between 1 and 2 grams of algae oil per day significantly elevates blood levels of DHA and EPA. This dose can also help to lower blood triglycerides and raise HDL levels.
Flax is one of the oldest cultivated crops, with evidence suggesting that it was cultivated in Babylon in approximately 3000 BCE.
The seeds have traditionally been used in healing, and the fibers for producing fabric, such as linen, and rope.
Similarly to flax seeds, flaxseed oil is a rich source of the omega-3 fatty acid ALA, which can be converted in small amounts to EPA and subsequently to DHA.
How does flaxseed oil boost health?
Several studies have found that flaxseed oil can benefit heart health.
A prospective, two-group, parallel-arm study compared the effects of flaxseed oil to those of safflower oil.
Supplementing with one tablespoon (15ml) of flaxseed daily for 12 weeks led to significantly lower systolic and diastolic blood pressure levels than supplementing with safflower oil (18).
Another randomized, double-blind, crossover study found that 10g of flaxseed taken daily for 12 weeks was able to significantly reduce LDL cholesterol levels (19).
Flaxseed has also been shown to be beneficial in relieving constipation.
A 4-week, double-blind, randomized controlled trial found that 4 mL/day of flaxseed oil significantly increased the frequency of bowel movements and improved stool consistency (20).
Flaxseed oil can also boost skin health.
A randomized, double-blind 12-week intervention study found that supplementation with flaxseed oil led to decreased skin sensitivity, roughness and scaling, and increased smoothness and hydration (21).
Flaxseed can reduce inflammation.
A systematic review and meta-analysis of randomized controlled trials found that flaxseed significantly reduced C-reactive protein, a key marker of inflammation (22). Interestingly, it seems to be most effective in those with higher BMIs.
How do I take flaxseed oil?
Flaxseed oil can be taken in liquid or capsule form.
If taking a liquid, it is recommended to take one tablespoon per day (15ml). If taking capsules, it is recommended to take 500mg per day.
Although flaxseed oil has a number of benefits, due to the low conversion efficiency of ALA to EPA and DHA, it is not recommended to be relied upon as a source of EPA and DHA for vegans and vegetarians.
Algal oil is a better alternative for this purpose.
Perilla oil refers to any oil derived from the perilla frutescent plant. Usually, it refers to the oil that has been processed from roasted seeds, which gives it a nutty taste. It is high in the omega-3 fatty acid ALA and rosmarinic acid.
How does perilla oil boost health?
Perilla oil has been shown to be beneficial for heart health.
Supplementation of perilla oil twice daily for 12 weeks improved the lipid profile and inflammatory biomarkers, as indicated by a decrease in triglycerides, total cholesterol and LDL levels (23). The effectiveness was similar to a mild exercise regimen consisting of 30-60 minutes four times a week of cardiovascular exercise.
Perilla oil has also been found to be effective in reducing asthma symptoms.
Between 10 and 20 grams of perilla seed oil taken daily for 4 weeks was able to significantly reduce levels of the inflammatory compounds, leukotriene B4 and C4 as well as improving lung function (24).
How do I take perilla oil?
Perilla oil can be taken in liquid or capsule form. If taking it as a liquid, it is recommended to take between 10 and 20g per day. If taking in capsule form, it is recommended to take 500mg per day.
It can be taken with or without meals and at any time of the day.
Tetradecyl Thioacetic Acid
Tetradecyl Thioacetic Acid (TTA), is what is known as a PPAR-alpha activator. It is an omega-3 fatty acid. However, it has a sulfur group at the omega-3 position which means that it cannot be burnt for energy and thus has no relevant caloric value to humans.
How does tetradecyl thioacetic acid boost health?
TTA has been shown to be beneficial for heart health.
A study found that 1g of tetradecyl thioacetic acid taken daily in four divided doses for 4 weeks was able to significantly reduce total cholesterol, LDL cholesterol, triglycerides, and LDL/HDL cholesterol levels when consumed alongside a cholesterol-reducing diet (25). Reduced levels of inflammation, as indicated by lower plasma levels of tumor necrosis factor were also found following supplementation.
It has also been shown to improve blood pressure.
An open-label study found that 1g of TTA taken daily for 28 days decreased LDL and increased in HDL, as well as reducing in diastolic blood pressure from 88 to 83 and slightly reducing systolic blood pressure from 136 to 133 (26).
TTA also has anti-inflammatory effects.
A double-blinded, placebo-controlled trial found that 1000 mg of TTA taken daily for 28 days reduced total cholesterol by almost 8%, triglycerides by 16% and total fatty acids by 12% (27). The HDL to LDL ratio improved and three markers of inflammation decreased (IL-6, TNF-a, and VCAM-1) over the course of the study.
TTA has also been demonstrated to have high bioavailability. A study testing its pharmacology and safety found that TTA was is detectable in the blood following a week of supplement cessation (28). However, it was not detectable three weeks later, highlighting the importance of continual supplementation in order to retain health benefits.
How do I take tetradecyl thioacetic acid?
Although more evidence is needed in order to find the most optimal dose, the current standard dose used in research demonstrating benefits is 1g per day, taken in divided doses with meals.
Both omega-3 and omega-6 essential fatty acids are hugely important for health. As they cannot be made by the body, they must be obtained from food or supplementation.
As Western diets tend to have sufficient amounts of omega 6, omega 3 supplementation is particularly important in order to maintain the necessary ratio between the two in the body.
As vegetarians and vegans do not consume fish, it is especially important to take essential fatty acid supplements that provide EPA and DHA, ideally from algal oil.
Keep Reading: 10 Best Herbal Supplements for Overall Health
ⓘ Any specific supplement products & brands featured on this website are not necessarily endorsed by Emma.
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About the Author
Emma Green has a PhD, MSc and BSc in Psychology and is a certified personal trainer. She currently works as a freelance writer, producing on content on science, health and fitness for a number of online platforms. She also coaches clients online on a one-to-one basis to help them achieve their health and fitness goals. Contact Emma.