- What is EPA and DHA?
- If we can convert, why supplement?
- 1st reason: ideal omega 3 to 6 ratio
- 2nd reason: EPA DHA benefits
- 3rd reason: conversion process of ALA
- 4th reason: omega 3 recommended intake
- 1st rebuttal: total ALA matters, not ratio
- 2nd rebuttal: vegans have higher DHA levels
- 3rd rebuttal: EPA and DHA side effects
- 4th rebuttal: contaminated fish oil
- 5th rebuttal: the vitamin A analogy
What is EPA and DHA?
EPA is short for Eicosapentaenoic acid and DPA stands for Docosahexaenoic acid. Most articles and even doctors claim these are forms of omega 3 fatty acids which are exclusively found in animal-based foods; fish and seafood naturally, as well as unnaturally through the eggs of hens which are fed a special omega 3 enriched diet.
Only animal-based foods is not an entirely correct answer. When it comes to what most would classify as human food, then yes it is true that there are only animal sources for DHA and EPA. But cold-water fish – which are by far referenced as the best source – are not actually making those nutrients themselves.
Rather, the fish are obtaining it from the marine plants they eat. Or if those fish are higher up on the food chain, from the smaller fish they eat which are consuming those plants. Likewise for krill and any other animal you can think of. So technically speaking, the original source for all omega 3 fatty acids is vegetarian/vegan, not fish.
The marine plants which make EPA and DHA – certain species of algae – are not considered to be a human food source. Of course technically, just like someone can go catch a fish and eat it, there’s nothing stopping a human from grabbing a clump of algae and eating it, too. Even if you did that though, it wouldn’t be a good food source, because of the vast quantities you would need to eat in order to obtain the recommended daily dosage.
ALA, the mother omega 3
What’s the difference between EPA, DHA and ALA? The latter stands for alpha-linolenic acid, which is what EPA and DHA are derived from. ALA is considered an essential omega fatty acid because humans can’t create it and therefore we need to acquire it from dietary sources. It’s a necessary nutrient for life and regular consumption is needed, since unlike most other fats, our body has limited storage capacity for omega 3.
ALA is found in land-based plant foods, especially nuts, seeds, soybeans, green leafy vegetables, and some refined oils like walnut and flax oil. Since EPA and DHA is found in so few food types, when you hear people say omega 3 fatty acids, they are almost always referencing alpha-linolenic acid (ALA). Are EPA and DHA essential fatty acids? No, because humans can create it by converting ALA to EPA and DHA.
Although much more complicated than depicted, that’s the order your body converts ALA to first become EPA, and then DHA. Both forms have different health benefits which we will discuss in a moment.
In short, the consensus definitions of each can be summed up as:
ALA = plant-based omega 3
DHA & EPA = fish-based omega 3 (originally coming from algae)
Does red meat contain omega 3? How about dairy, chicken, turkey, pork, and other meats? No land-based animals can provide you with any significant amounts of DHA and EPA, since they aren’t consuming algae. The only amounts they can provide – if and when it’s even enough to measure – will be what their own body has converted from ALA, which will be quite negligible.
However land-based animals can provide you with ALA, albeit in very small quantities. They can get it from what they eat, but it’s not much. Beef from the typical grain-fed cattle only provide about 1% of their fat content in the form of omega 3 and even with grass-fed, it’s only 7% (1). That means meat from land-based animals is almost entirely omega 6 and other fatty acids (most non-essential).
If we can convert, why supplement?
You will find very well educated scientists and doctors on both sides; some advocating for supplements, while others are against them. As you may guess, the lion’s share are for taking a DHA EPA supplement.
1st reason: ideal omega 3 to 6 ratio
The biggest pro-supplementation argument is that the typical Western diet has an out-of-control omega 3 to 6 ratio. As hunter-gatherers, it has been proposed that originally, humans were consuming omega 6’s and omega 3’s in roughly a 1:1 ratio. Today, the Westernized diet is said to be around a 15 to 1 or 16 to 1 ratio (2). That means you you might be getting only 7% of the omega 3 you should be!
This may have devastating side effects on your health. Research has suggested that excess omega 6 polyunsaturated fatty acids (PUFA) have been correlated with and therefore may contribute to:
- Cardiovascular diseases including increased risk of heart attacks, arrhythmia (3), and thrombosis (4)
- Diseases worsened by inflammatory environments such as cancer proliferation (5), arthritis (6), nonalcoholic fatty liver disease or NAFLD, Crohn’s disease and ulcerative colitis (7), inflammatory bowel disease or IBD, Alzheimer’s disease (8) (9), and asthma (10)
- Psychiatric disorders including depression, bipolar disorder (11), unproductive behaviors, and increased risk of suicide and homicide (12)
- Strokes (13)
- Obesity (14)
As you see, research has suggested that omega 3 deficiency symptoms may cause a laundry list of side effects and worsen many diseases. Being an essential fatty acid, this should come as no surprise.
2nd reason: EPA DHA benefits
Due to the reported health benefits, many healthcare professionals recommend daily supplements whether they’re omega 3 vegetarian capsules made from algae, from fish oil (salmon, mackerel, anchovies, tuna, etc.), or from a crustacean (krill).
The fish derived supplements are by far the cheapest. Purely vegan sources of DHA and EPA like the Ovega 3 brand of softgels made from algae are often times more expensive on a per serving basis (but with a benefit of no fishy taste/breathe). Krill oil is popular too and very reasonably priced, but since it’s a crustacean those with shellfish allergies most likely can’t have it.
In addition to avoiding the above list of side effects which may be linked to deficiency, supplementation has been stressed as being important for a couple of other purposes.
For several decades now, a plethora of studies have suggested that healthy levels during pregnancy can be extremely beneficial for the developing baby.
It is said to be especially important during the last trimester of pregnancy and during the first 6 months after birth. It is during this crucial time when there is much greater accumulation of the DHA in the baby’s brain and retina (15).
For healthy vision and development of the baby’s central nervous system, this is why many infant formulas add DHA to bring up the levels so they’re comparable to that found in a mother’s breast milk (0.2-0.3 wt% of total fatty acids).
It is also why many healthcare professionals and obstetricians recommend pregnant and lactating women consume a DHA dosage of 200 to 300 mg per day (16). Getting that purely from fish and seafood can be dangerous due to mercury levels, and hence, why many advocate for a highly refined fish oil which has been thoroughly tested for contaminants.
For men and non-pregnant women, both young and especially old, the suggested benefits of EPA and DHA are often linked to brain health.
The human brain is nearly 60% fat and as many Americans try and adapt a low fat diet, they may be starving their brain of the good fats (17).
Dieters and non-dieters alike are already getting plenty of omega 6’s since it’s in practically all the fats we eat, from the oils we fry our foods in to the high amounts of meat and dairy which are part of the Western lifestyle. Good DHA fish sources are not regularly consumed and most Americans eat too few ALA plant sources for adequate conversion.
Even those who think they are eating healthy fats, like olive oil, are fooling themselves. Its omega 3 to 6 ratio is better than many others, but olive oil is still unhealthy with a ratio of 1:13 for omega 3 to 6 levels. The only benefit EVOO really has is its high smoke point, which makes it one of the least evil choices for frying and high-heat cooking. Even though it’s rich in omega 3, flax oil would be a terrible choice for that due to its very low smoke point.
What is DHA good for in adults?
Even though our bodies are not developing like a growing baby or child, our retina and visual cortex still need DHA. Healthy levels are associated with better visual acuity.
Improved cognitive function has also been linked to having a healthy amount of DHA. Aside from their role in the structure of the brain, essential fatty acids are involved in the neurotransmitter or “messenger” and signaling processes which take place (18).
What is EPA good for in adults?
Is EPA better than DHA or more important than it? No, they both do different things.
Unlike DHA, there are not high levels of EPA in the brain. In fact once it enters the brain, it oxidizes rapidly. That’s why EPA levels in the brain are 250 to 300x lower than DHA (19). The difference between the two may suggest EPA doesn’t offer any cognitive benefits, but research has suggested it indirectly benefits the brain. Why is it beneficial?
- EPA inhibits the enzyme delta-5-desaturase (D5D) which is responsible for the production of the omega 6 fatty acid known as arachidonic acid (AA) (20).
- Eicosanoids (compounds derived from AA) are a primary reason why excess omega 6 is inflammatory (21).
- This means the healthier amounts of EPA you have, the less inflammation you may have from excess omega 6.
So even though EPA may have very little direct involvement in neurological processes, it may benefit the entire body – including the brain – by reducing inflammation. Perhaps now more than ever, EPA is especially important given the modern Western diet.
3rd reason: conversion process of ALA
Supplement advocates point to the slow and complicated way how our bodies first convert alpha-linolenic to EPA, which is a precursor to DHA and needs to undergo additional conversions to create it. Since DHA undergoes the most processes, it is the one people are most vocal about needing a supplement for.
Women vs. men
Perhaps women are the stronger gender, because they definitely beat men in conversion efficiency! Studies have shown that even in healthy young men, only about 8% of ALA is converted to EPA and just 0 to 4% as DHA (22).
Contrast that to young women who have over double the conversion efficiency; 21% of ALA converts to EPA and 9% to DHA (23). It has been speculated this may have something to do with estrogen vs. testosterone levels, with lower levels of estrogen adversely affecting the conversion process (24).
The keywords here are “healthy” and “young” males and females. As with just about all biological processes, the older we get the less efficient we are. That along with age-related cognitive decline is a reason why fish or vegan DHA supplements are especially recommended for older adults.
Not only does gender play a role, but also your ethnicity may affect how well (or not) you can convert.
Known as the fatty acid desaturase gene (FADS1), it is though to play a role in conversion efficiency (25). Those who carry this gene are believed to have lower conversion rates. Research points to around 40 to 50% of Hispanics, Chinese, and Japanese as being carriers.
On the other hand, those of European, African, and Middle Eastern descent tend to be less affected and therefore, are more likely to have an easier time converting plant based omega 3 (ALA) to EPA and then DHA. It is believed that this trait may have developed over time as the diets in these regions lend themselves naturally to having more plant-based sources of ALA.
4th reason: omega 3 recommended intake
What is the recommended daily intake of EPA and DHA? The daily value dosage amounts vary among world governments. Here’s a look at what the USDA and EFSA recommend.
- General population – 8 ounces per week of seafood, which should provide an average of 250 mg per day of EPA and DHA
- Women who are pregnant or breastfeeding – 8 to 12 ounces per week of seafood from those which are specifically lower in mercury
EFSA (European Food Safety Authority) (28):
- Infants and young children (7 to 24 months) – 100mg per day of DHA
- Children (2 to 18 years) – 250 mg per day of EPA + DHA
- Adults – 250 mg per day of EPA + DHA
- Women who are pregnant or breastfeeding – 250mg per day of EPA + DHA, plus an additional 100 to 200mg per day of DHA
The vast majority of people in the United States do not consume enough seafood to get the recommended dosages listed above. Many argue that’s actually a good thing. Given how polluted the oceans and lakes, eating so much seafood can lead to heavy metal contamination.
Those on a vegan or vegetarian diet are not getting any direct sources of the two omega 3 converted forms (and getting it from marine plants would require excessive intake). The amounts of ALA in the vegetarian diet may not be adequate either, given how little of it actually gets converted in both genders, plus the role your genetics may play.
In short, there are good reasons why you should supplement regardless of whether you eat a typical Western diet, a healthier Eastern diet, or even a vegan diet.
Though not everyone is on the supplement bandwagon. Even when people have zero fish in their diet, there are many who argue that it’s not necessary as long as you are getting adequate amounts of alpha-linolenic acid. Much of the evidence to support that argument is even more recent than the earlier studies published during the 90’s and 00’s, which were largely responsible for generating the omega 3 buzz in the first place.
1st rebuttal: total ALA matters, not ratio
The prestigious American Journal of Clinical Nutrition published a human study in 2006 which looked at high and low ALA diets (29).
For the first 4 weeks, 29 people received a controlled diet with 7% of calories coming from omega 6 and 0.4% coming from omega 3, which created a 1:19 ratio for 3’s vs 6’s.
For the next 6 weeks, the same 29 people were split up into 2 groups:
- Group 1 had a diet with 3% of calories coming from omega 6 and 0.4% from omega 3, which is a 1:7 ratio.
- Group 2 had 7% of calories coming from omega 6 and 1.1% from omega 3, which is also a 1:7 ratio.
Both groups had a 1:7 ratio, but the group with 1.1% from omega 3 (vs. 0.4%) had much higher DHA synthesis.
These findings suggest that even with a poor omega fatty acid ratio from diet and without DHA food sources, what determines whether or not we get adequate DHA is how much plant-based or vegetarian omega 3 sources we have in our diet.
2nd rebuttal: vegans have higher DHA levels
Even higher than fish eaters! That’s from a 2010 study which was published in the American Journal of Clinical Nutrition (30).
The researchers looked at 14,422 people between the ages of 39 and 78. Among them were men, women, meat-eaters, vegatarians, and vegans.
Guess what? Even though omega 3 intakes were 57-80% lower in the non-fish eaters (vegans), the amount of DHA in their blood was actually found to be higher at 286.4 micromoles per liter versus 271 for the fish eaters.
If one needs fish for adequate DHA as many claim, then why do the vegans have the highest amounts, despite taking in no direct sources of DHA? It’s likely because they are taking in higher amounts of the precursor – ALA – and the ultimate effect that has even exceeds those who consume fish + lower amounts of ALA. It’s hard for the pro-fish crowd and vegan haters to brush this study aside given how large the sample size was – over 14,000 people.
3rd rebuttal: EPA and DHA side effects
Can you overdose on EPA and DHA? Fishy taste and bad breathe will be the most likely side effects when used in moderation.
Although it’s considered to be “possibly safe,” no one is certain whether or not large amounts of these are entirely safe. Even in moderate amounts, side effects can include nausea, gas, watery stools, plus increased bleeding and bruising (31).
While not officially recognized as side effects, we have read comments on forums and seen product reviews from customers who talk about undesired mental side effects with DHA supplements.
In amounts of 3 grams per day or higher, DHA is known to thin the blood and that can definitely be quite dangerous for those with certain medical conditions like warfarin (32).
The DHA side effect of lower blood pressure may be considered desirable for most people, but for those on blood pressure lowering medication it can wreck havoc. Likewise for those who have too low of blood pressure (hypotension).
Ultimately, this means the overdose level can vary greatly depending upon a person’s unique circumstances.
4th rebuttal: contaminated fish oil
Anyone who buys omega 3 supplements knows how the marketing goes. Manufacturers will say their cod are caught in remote arctic waters or it’s sourced from organic wild caught Alaskan salmon. A century or two ago, that would have been plenty sufficient for providing an absolutely pure source of fish oil. However we have now polluted the earth so badly, it’s hard to justify anywhere as being completely safe.
Estimates peg the pollution of mercury each year as growing by a staggering 5,000 to 8,000 metric tons (33). As if that’s not crazy enough, with all the corners cut by China, who knows what the real number is. It’s the reason why fish are some of our biggest dietary sources of toxic metals and other harmful compounds:
- Strontium and other radioactive substances
Going back to the marketing verbiage used by many fish oil manufacturers, they forget to tell you that contaminants rapidly spread. Yeah, obviously casting your fish nets in the China sea would be a disastrous idea, but even remote arctic regions are heavily polluted due to ocean and wind currents.
It’s the same reason why 29% of San Francisco’s air pollution is actually from China and Asian industrial pollution, coming all the way from the other side of the world (34). So do you really think your fish oil is automatically safe just because it comes from a distant location?
Even the U.S. government admits that any and all fish need to be consumed in limited moderation. It’s why for pregnant women, they insist on them only eating a cumulative max of 2 servings per week of fish/seafood and only from species with lower mercury levels. For canned albacore or chunk white tuna, the limit is only 1 serving per week, since those have more mercury than canned light tuna (35).
The reason fish are so problematic is that with many of these toxins – particularly mercury – once they’re in a body (human or animal) they’re hard to get out. With fish that’s a big problem, because it’s not just the mercury from that specific one fish on your dinner plate, but all the other smaller fish it ate over its lifetime. It’s not just mercury from the one fish, but all the smaller fish it ate over its entire lifetime.
That’s why as tiny as a fish may be, it can contain such high amounts of mercury. It’s also the reason many people are opting for non fish oil omega 3 supplements, even though they cost a lot more. Those made from algae don’t have the “the fish and all the fish it ate” problem.
5th rebuttal: the vitamin A analogy
Vitamin A found in plants is beta-carotene. It’s not actually vitamin A, but rather a precursor to it. Our body converts what we need and disposes of the rest.
A few decades ago scientists thought the superior form was the final form, preformed vitamin A. They began synthesizing it in labs and using it in multivitamins and dietary supplements. The logic was that it’s better to get the final form than have our body go through processes to make it.
With beta carotene, you could literally take in 1,000% more than you need and your body will excrete it. The worst side effect may be temporary yellowing of the skin and nails. But with preformed vitamin A (as found in many supplements) even if you take in 150% of what you need, you may be in trouble. This is because our body can’t get of excess if it’s already in the converted form.
It’s why U.S. Dept. of Health and Human Services strongly warns against the risk of possible birth defects when a pregnant women takes a supplement with more than 5,000 IUs of preformed vitamin A.
Will the same thing happen if you eat too many carrots? The NIH says this: “High intakes of beta-carotene do not cause birth defects or the other more serious effects caused by getting too much preformed vitamin A” (36).
Is it possible that a decade or two from now, we will come to discover the same may be true with DHA and EPA, that too much may actually be bad for you? Is it possible the same logic with vitamin A applies to alpha-linolenic acid… our body converts what it needs and forcing more isn’t necessarily healthy? Is it possible that while it’s true many (or most) people have DHA and EPA deficiencies, the best solution is more omega 3 in the form of ALA?
As with all things in nutrition, only time will tell which theory is right. But one thing you can take to the bank now is that you might not be getting enough omega 3’s. Evidence from the latest research definitely supports the use of supplements for people who aren’t consuming enough omega 3 from plants, especially during pregnancy. But everyone should consult their doctor prior to taking a supplement.
Adding dietary sources like chia seeds and flax oil can be great, but even with those, a high quality ALA supplement may still be a good idea. Or if supplementing with the final forms, vegetarian EPA DHA coming from algae may make sense even for meat eaters, in order to circumvent the heavy metals and other toxins associated with fish oils.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.