EPA vs. DHA in Omega-3: What’s the Difference?

Before we dive into the specifics of EPA and DHA, it’s important to understand fatty acids and the role they play in your health.

Omega-3 and omega-6 are two essential fatty acids, meaning that your body can’t create them on its own, so they must be obtained from food or supplementation.

This might be trickier than you think…

1. Your body can only take a limited amount of omega-6 and omega-3s at once.
2. It’s crucial that you get the right ratio of omega-6 fats to omega-3 fats.

While the diet of our hunter-gatherer ancestors had an omega-6 to omega-3 ratio of 4:1 or less, our modern diet exhibits a hefty 20:1 ratio (1).

When too many omega-6s are consumed, your body is thrown into an inflammatory state, leading to a heightened risk of health issues like obesity, heart disease, type 2 diabetes, autoimmune disorders, cancer, depression, irritable bowel syndrome (IBS), and rheumatoid arthritis (1, 2).

This huge shift in the omega-6 to omega-3 ratio is largely due to the overconsumption of industrial seed oils (e.g., corn, soybean, safflower oils) paired with low intake of EPA and DHA. Today's average intake is about 100-200 mg/day, which pales in comparison to the 660-14,250 mg/day during Paleolithic times.

Low consumption of omega-3s—specifically EPA and DHA—has been determined by a study from Harvard to be one of the top six preventable causes of death, accounting for an estimated 84,000 deaths per year in the U.S. (3).

Conversely, higher levels of omega-3s may add healthy years to your life.

In the groundbreaking Framingham Heart Study, 2500 participants were assessed for red blood cell levels of EPA and DHA. Those with the highest levels of EPA and DHA had a 34% lower risk of dying from any cause compared to those participants with the lowest levels (4).

The potent ability of EPA and DHA to suppress inflammation throughout the body plays a key role in its life-extending benefits. Chronic inflammation is linked to the development of most of the major chronic diseases such as cardiovascular disease, cancer, type 2 diabetes, kidney disease, non-alcoholic fatty liver disease, autoimmune diseases, and neurodegenerative disorders (e.g., Alzheimer's disease) (5).

Now that we’ve covered the basics of omega-3 fatty acids, it's time to get into the details about EPA and DHA.

There are three main types of omega-3s:

• Alpha-linolenic acid (ALA)
• Eicosapentaenoic acid (EPA)
• Docosahexaenoic acid (DHA)

Of the three, ALA (found in nuts and seeds) is the only fatty acid that is essential because it can’t be made in the body (6).

EPA and DHA can technically be produced in the body from ALA, but there’s a catch—the conversion rate is pretty low. We're talking about 0.2% to 6% for EPA and less than 0.5% for DHA (7, 8).

So, even though your body can make them to some extent, it's not enough to meet the demand. That's why they're considered conditionally essential fatty acids. To ensure you're getting enough, you need EPA and DHA directly from foods like oily fish or supplements (9).

It’s important to note the health and longevity benefits above are provided by EPA and DHA, not by ALA (10).

We touched on a few of the incredible health benefits of EPA and DHA, but let’s dig a little deeper.

1. Supports Cardiovascular Health

The benefits of EPA and DHA for heart health are supported by decades of research.

A 2022 review of 884 clinical trials evaluated 27 supplements for their ability to benefit cardiovascular health. Omega-3s ranked in the top three nutrients that improved cardiovascular health. Specifically, omega-3s reduce the risk of heart attack, coronary heart disease events, and deaths from cardiovascular disease (11).

Native Note: As a further testament to the therapeutic potency of EPA and DHA, consider that there are prescription versions of EPA (Vascepa) and EPA+DHA (Lovaza) FDA-approved for lowering high triglycerides (12, 13).

2. Improves Brain Health

Since fat makes up nearly 60% of the brain … and omega-3s account for 35% of that amount … it would be expected that omega-3s play vital roles in brain functioning and health. Multiple studies have shown that EPA and DHA supplementation improves cognitive performance, memory, learning, and blood circulation in the brain (14).

One way this happens is by omega-3s making cell membranes in the brain more fluid and flexible. This helps neurotransmitters like serotonin and dopamine connect to their membrane receptors more easily, improving brain function (15).

3. Reduce Inflammatory Conditions

The strong anti-inflammatory effects of EPA and DHA have been shown to benefit various inflammatory disorders. For example, a review of nine clinical trials concluded that omega-3s are effective at alleviating pain and improving joint function in patients with osteoarthritis (16).

Although osteoporosis is not typically regarded as an inflammatory condition, chronic inflammation is a major driver of age-related bone loss. Data from the National Health and Nutrition Examination Survey (2005-2008) showed a significant association between EPA and DHA supplementation and higher bone mineral density of the lumbar spine in older adults (17).

In a study utilizing genetic data, dietary supplementation with omega-3s was found to provide significant protection against inflammatory bowel disease (IBD) and, according to the study authors, should be considered as an option in the treatment of the disease (18).

4. Reduce the Risk of Cancer

EPA and DHA have well-documented anticancer effects, particularly against colorectal, prostate, and breast cancer. This is due in part to their anti-inflammatory and immune-regulating effects. EPA/DHA can also be used to improve the efficacy of chemotherapy drugs by sensitizing cancer cells (including some drug-resistant cells) to the drugs (19).

An association between high consumption of EPA/DHA-rich fish oil and a reduced risk of pancreatic cancer has also been reported (20).

5. Promote Muscle Health

The benefits of omega-3s for the heart and brain are pretty well-known…but did you know they’re actually really good for your muscles too?

Emerging evidence suggests that EPA and DHA can help promote muscle mass, increase strength, and help prevent age-related muscle loss (sarcopenia). EPA and DHA help your muscles grow stronger by increasing the production of muscle-building proteins and making your muscles more responsive to activities like resistance training and eating protein-rich foods. (21).

Daily supplementation with 5 grams of EPA/DHA in healthy young women prevented the decline in muscle size and mass resulting from two weeks of leg immobilization (muscle disuse) (22).

At this point in the blog, it's clear that the combination of EPA and DHA provides a wide variety of profound health benefits. Still, it’s important to know the distinction between the two for your specific health needs.

The difference between EPA and DHA lies in their chemical structures. EPA, with 20 carbon atoms and 5 double bonds, produces eicosanoids known for their potent antioxidants (23).

On the other hand, DHA has 22 carbon atoms and 6 double bonds, comprising about 8% of total brain weight.

These structural differences influence some of the distinct health benefits of EPA and DHA.

Improves Mood Disorders

In a review of 26 clinical trials, improvements in depression were demonstrated in participants who took supplements with either 100% EPA or an omega-3 formulation of 60% or more EPA.

No antidepressant effects were observed in those who took pure DHA or a DHA-dominant omega-3 supplement (24). One reason that may account for an EPA advantage over DHA is its greater ability to support the growth and survival of nerve cells.

Supports Joint Health

Animal studies have suggested that EPA exhibits stronger anti-inflammatory effects than DHA in animal models of inflammatory joint diseases such as rheumatoid arthritis and osteoarthritis (25, 26).

Supports Immune Function

A study of 21 adults with chronic inflammation compared the immune effects from supplementation with 3 grams of either EPA or DHA for 10 weeks.

The results?

EPA was found to be more effective than DHA at regulating the immune system by enhancing the balance between anti-inflammatory activity and proinflammatory activity (27). A balanced immune response is critical in the prevention and management of inflammatory and autoimmune disorders.

Essential For Healthy Fetal Development

During fetal and infant development, high concentrations of DHA accumulate in the central nervous system and retina, where they play important structural and functional roles (28).

For example, in a controlled trial of 350 pregnant women, infants from mothers supplemented with 600 mg DHA per day during the last two trimesters were consistently more attentive and less fussy during the first year of life. Sustained attention dropped off in the placebo group (29).

Reduces Risk of Premature Birth

The risk of early preterm birth (< 34 weeks gestation) is linked to low fish consumption and low blood levels of DHA in the mother. Several prominent health organizations, including the Food and Agricultural Organization of the UN, recommend that pregnant women consume a minimum of 200 mg/day of DHA from either fish or supplements (30).

Supports Brain Health

DHA is the predominant fatty acid in the brain (31). This high fatty acid content helps regulate the function and structure of the neurons, the messengers of the brain. A meta-analysis of 15 intervention studies found that DHA supplementation exceeding the average amount in the studies (580 mg/day) significantly improved long-term memory in healthy adults (18-90 years old) with mild memory complaints (32).

Native Note: DHA makes up a whopping 97% of the brain’s omega-3 fatty acid (33).

Supports Eye Health

The retina is actually an extension of the brain. Like the brain, it is highly concentrated in DHA. In fact, it has more DHA than any other tissue in the body. A dietary deficiency of DHA is associated with impaired vision, while low retinal DHA increases the risk for retinopathy and other eye disorders.

Interestingly, the amount of DHA in the retina can be increased by the phospholipid form of DHA (as found in krill oil) but not by the triglyceride form of DHA (as found in fish oil) (34).

While fish oil supplements remain popular as a concentrated source of EPA and DHA, krill oil is an alternative that has some distinct advantages.

Unlike fish oil, which comes in a triglyceride form of EPA/DHA, the EPA/DHA in krill oil is wrapped up in another type of fat called phospholipid. Research shows that because phospholipids are the main fat in cell membranes, they might get absorbed by your body more effectively. (35).

Also, many krill oil supplements contain astaxanthin—a powerful antioxidant that protects the fatty acids from oxidative damage (rancidity) (36).

Is EPA or DHA Better For Cardiovascular Health?

The debate on whether EPA or DHA gives better heart benefits is still ongoing. They both have their perks when it comes to heart health—many of which actually work hand in hand. (37).

A study comparing fish oil supplements rich in EPA versus DHA found that both omega-3s have comparable positive impacts on blood lipids like LDL cholesterol, HDL cholesterol, and triglycerides (38).

Plus, there's a solid body of evidence backing the heart-protective advantages of EPA and DHA combined. A recent meta-analysis of 40 studies even concluded that the risk of a deadly heart attack could drop by 35% with both omega-3s together. Therefore, if you're looking to protect your heart, going for a supplement that combines EPA and DHA rather than choosing one over the other would be more practical (39).

How Much EPA & DHA Do You Need?

Both the American Heart Association and the 2015-2020 Dietary Guidelines for Americans advise eating a 3.5 - 4 oz serving of fish twice per week to attain a daily intake of 250 mg/day of combined EPA and DHA (40). If you eat little or no fish, you should consider taking a supplement daily or several times a week. According to the U.S. FDA, supplementation with EPA+DHA up to 5 grams/day is safe (41).

Do You Need Both?

EPA and DHA are both omega-3 fatty acids and have similar benefits, but they each offer more specialized benefits that could make one more suitable to your needs than the other. EPA is known for its powerful antioxidant properties, as well as its promotion of cardiovascular and cognitive health. DHA is crucial for brain and eye development throughout life.

Most omega-3 supplements contain both DHA and EPA, so if you need to choose one over the other, it is best to make the decision in conjunction with your physician or healthcare provider.