Do you know what EPA and DHA are? And perhaps, you’ve never thought about or completely unaware of the small details that different EPA:DHA ratios have completely different effects on the body. How do you choose to experience the benefits of fish oil? Today, we’re going to unlock the secrets of EPA and DHA in fish oil.
I believe that many people have the habit of taking health supplements in their daily lives, such as fish oil, probiotics, and calcium. Among these, fish oil has been in the market for many years, and people choose fish oil based on its Omega-3 content. You might have heard that fish oil is rich in Omega-3 (EPA and DHA), but do you know what EPA and DHA really are? Moreover, there’s a little-known detail that the different EPA:DHA ratios have vastly different effects on the body. How can you choose to feel the benefits? Today, let’s dive deep into the world of EPA and DHA in fish oil.
What is Omega-3 (EPA/DHA) in fish oil?
Fatty acids can be divided into saturated and unsaturated fatty acids based on their saturation level. Among unsaturated fatty acids, they can be further divided into monounsaturated and polyunsaturated fatty acids. Omega-3 in fish oil is a type of polyunsaturated fatty acid.
What is EPA?
EPA is an Omega-3 fatty acid. EPA stands for Eicosapentaenoic acid, which means it is a fatty acid with 20 carbon atoms and 5 double bonds. It is generally written as (C20:5,ω-3).
What is DHA?
DHA is also an Omega-3 fatty acid. DHA stands for Docosahexanoic acid, which means it is a fatty acid with 22 carbon atoms and 6 double bonds. It is generally written as (C22:6,ω-3).
Did you know that the EPA:DHA ratio has different effects on the body? While it’s common knowledge that fish oil primarily contains two fatty acids, EPA and DHA, what’s less known is that the EPA:DHA ratio has different effects. Moreover, the choice between supplements rich in EPA or DHA can differ depending on the specific health condition. Let’s explore these aspects in six common situations.
- Cardiovascular Protection
- Myocardial Infarction and Sudden Death: In a retrospective review of 11 studies (two involving dietary intake of deep-sea fish and nine using fish oil supplements), with EPA:DHA ratios ranging from 3:2 to 1:2 and an average intervention duration of up to 20 months, it was found that this combination effectively reduced the risk of myocardial infarction by 30%, decreased the risk of sudden death by 30%, and reduced overall mortality by 20%.
- Triglyceride Reduction: Omega-3 fatty acids, including both EPA and DHA, are known to effectively reduce fasting and postprandial triglycerides by 14-35%. Some studies suggest that DHA’s effect may be greater, but the difference is not very pronounced.
- Blood Pressure Improvement: Omega-3 fatty acids have been shown to improve blood pressure by enhancing endothelial function. DHA, in various experimental models (animal or human), has shown more significant effects than EPA in lowering diastolic and systolic blood pressure. Additionally, DHA has demonstrated better responses in improving endothelial function, but both EPA and DHA have anti-atherosclerotic effects.
Heart Rate Regulation
Increased heart rate is an important risk factor for cardiovascular disease mortality. In a study from 2005 involving over 1,600 healthy adults, supplementing with over 3.5 grams of Omega-3 (containing both EPA and DHA) for more than two weeks effectively reduced heart rate. Another study observed a reduction in heart rate only in the DHA group among overweight men with high lipid levels.
💡 In general, for cardiovascular protection, an EPA:DHA ratio of 3:2 to 1:2 is recommended. If your goal is to improve blood pressure specifically, you may opt for products with relatively higher DHA content.
Diets rich in fatty acids tend to have anti-inflammatory effects. Current results suggest that there is no significant difference in the anti-inflammatory effects of EPA and DHA. Most research experiments have used the standard fish oil ratio of EPA:DHA = 3:2.
💡 To achieve anti-inflammatory effects through fish oil supplements, it is recommended to consume the 3:2 EPA:DHA ratio.
Most research on the anti-depressant effects of EPA and DHA is based on epidemiological findings, with more evidence indicating that EPA has a stronger anti-depressant effect compared to DHA. According to current evidence, a daily dose of 2 grams of EPA has been found to improve severe adult depression.
💡 For depression-related health concerns, you may choose products with higher EPA content.
Omega-3 fatty acids, especially DHA, are highly concentrated in the retina of the eye. Therefore, many studies have investigated the relationship between fatty acid intake and eye-related diseases. Epidemiological studies have shown that increased consumption of fish and nuts helps reduce the risk of age-related macular degeneration.
💡 For vision health, you may choose products with higher DHA content.
Epidemiological studies have found that increased Omega-3 intake can lead to improved cognitive function and a reduced risk of dementia. Additionally, several studies have shown that DHA concentrations decrease in the brains of Alzheimer’s disease patients. Blood serum DHA levels can also serve as an independent predictor of dementia.
In a study from 2012 involving elderly individuals with mild cognitive impairment, three groups were formed: one rich in EPA, one rich in DHA, and one rich in Omega-6 fatty acids (linoleic acid). The study assessed depression symptoms, quality of life, and cognitive function. Results showed that both the EPA and DHA groups outperformed the Omega-6 fatty acid group on depression scales. However, only the DHA group demonstrated significant improvements in fluency of speech and self-rated physical health.
💡 To prevent or slow cognitive impairment, you may choose products with higher DHA content.
Pregnant Women and Fetus
Research indicates that dietary patterns with a higher ratio of Omega-6 to Omega-3 fatty acids are associated with an increased risk of postpartum depression. Omega-3 fatty acids have been positively associated with the health of pregnant women and fetuses. Clinical studies have found that supplementing with Omega-3 fatty acids during pregnancy can reduce the risk of premature birth and low birth weight.
Therefore, many global organizations related to maternal and infant health recommend that pregnant women supplement with Omega-3 fatty acids. During the third trimester of pregnancy, maternal DHA requirements increase as the fetus cannot synthesize sufficient DHA. Studies have shown that supplementing with DHA during the third trimester and breastfeeding can benefit the cognitive development and sleep patterns of newborns and result in higher IQs.
💡 Supplementing with Omega-3 (either EPA or DHA) during pregnancy can help reduce adverse effects during pregnancy and childbirth, such as premature birth or preeclampsia. For fetal brain development, it’s advisable to choose supplements with higher DHA content.