WARNING!
This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.
Dietary fats are essential to good health. Although it is harmful to eat too many of some, or not enough of others, without healthy fats your body will not work properly.1 Fat is used to keep your skin and hair healthy, absorb certain vitamins and insulate your body to keep you warm. Certain fats are essential since your body cannot make them.
Fat is required for brain development as well as controlling inflammation and blood clotting. The most dangerous type of dietary fat is trans fat, which is found in baked goods and processed foods.2 During processing, healthy oils may be turned into solids through a process called hydrogenation to extend their shelf life. During this process, trans fats are formed.
There are no health benefits from trans fats and it is not safe to eat any amount of them. Polyunsaturated fats are essential, which means you must eat them since your body doesn't make them. The two main types are omega-3 and omega-6 fatty acids. The number identifies the chemical bond in the fat.
While both are essential, most people eat them in the wrong ratio, which leads to an increase in chronic inflammation.3 Omega-6 is found in high concentrations in processed foods, corn oil, sunflower oil and safflower oil. The ideal ratio of omega-3 to omega-6 fats is 1-to-1.4 Unfortunately, the typical Western diet has a ratio up to 1-to-16.
Maintaining a low ratio may help reduce your risk of many of the chronic diseases prevalent in Western society. The excessive intake of omega-6 fats nearly tripled in the last 100 years with the introduction of vegetable oils.5 Researchers believe they may have discovered a formula that would help 95% of people raise their omega-3 index to a healthy range from 8% to 12%.6
What Is an Omega-3 Index?
Measuring omega-3 levels in your blood provides an indication of risk for chronic disease. In this short video William Harris, Ph.D., discusses the omega-3 index and the importance it has in evaluating your disease risk.
Omega-3 is measured on your red blood cells as a reflection of the amount found in the rest of your body. Before Harris developed the test in 2004, an assay was not available. Since the life span of a red blood cell is about 120 days,7 the test measures an average of your intake and isn't influenced by a recent meal that was high in omega-3.
The test has been used to evaluate data from several studies, including the Framingham Study and the Women's Health Initiative.8 The index is expressed as a percent of all fatty acids in the red blood cell membrane.9 Data from studies Harris performed showed the healthy range of omega-3 is from 8% to 12%.10
An international team of scientists led by researchers from Penn State University and OmegaQuant Analytics used the omega-3 index to model how it might be affected by eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation.11 These are long-chain fatty acids found in animal-based omega-3 fats.12
Achieving Your Target Omega-3 Index
As Harris determined, maintaining your omega-3 index in a low risk range reduces your chance of getting heart disease. However, it's been challenging for researchers and consumers to determine how much supplementation might be needed to achieve a healthy range.
The team's objective was to study the effects of EPA and DHA supplementation on volunteers' omega-3 index levels.13 Using a literature review, they identified data from 1,422 individuals participating in intervention trials where measurements of omega-3 index, sex, age, weight and duration of treatment were all recorded.
There were 846 individuals who were given EPA and DHA supplements, while 576 were given placebos. After analysis, the researchers found the supplement formulation, dose and baseline omega-3 index were predictors of response to the intervention.
The scientists believe the model they developed could be used by researchers to help estimate the physiological response to a dose and form of supplementation.14 As reported in NutraIngredients-USA,15 a dose of 2 grams of EPA and DHA in the triglyceride form is needed to raise omega-3 levels more than supplements in the ethyl ester form. The researchers said:16
"A dose of about 2000 mg/d of EPA + DHA is much higher than current recommended intakes to reduce CVD [cardiovascular disease] risk.
The 2015-2020 Dietary Guidelines for Americans recommend 8 oz of fish per week, which is said to be equivalent to about 250 mg/d EPA + DHA, and the American Heart Association recommends 1-2 servings of "oily" fish per week (assumed to approximate 500 mg/d EPA + DHA) to reduce CVD risk. Using the model and assuming the TG (triglyceride) form, these EPA + DHA intakes would increase the O3I from 4% to ~6%."
Omega-3 EPA and DHA are available in several forms, including triglyceride, ethyl ester, phospholipid and free fatty acid.17 The featured study evaluated the use of omega-3 in the triglyceride form, which is more prevalent in the food supply. In comparison, the ethyl ester form is chemically connected to ethanol during processing enabling EPA and DHA to be concentrated in supplements.
Health Benefits Associated With Achieving Target Levels
Harris18 found a significant association between the omega-3 index and the risk for coronary heart disease. Based on his results, he proposed that those with an omega-3 index below 4% were at high risk; those with an index from 4% to 8% experienced intermediate risk and those who had an index greater than 8% had a low risk for coronary heart disease.
In an effort to understand how this may occur, Harris and a team of researchers19 investigated levels of omega 3 compared to telomere length. The study involved 608 outpatients, through whom researchers identified an inverse relationship in the baseline levels of omega-3 fatty acids and telomere shortening over a five-year period.
In a subsequent study20 researchers used a randomized control trial to assess the effect of omega-3 supplementation on telomere length and oxidative stress. This four-month study21 involved evaluation of 138 middle-aged and older adults who were classified as overweight and sedentary. They found that telomere length increased with a decreasing omega-6 to omega-3 ratio. This suggests that even over a short study period, the ratio could impact cell aging.
A reduction in inflammation and improved cardiovascular health may also influence other health benefits associated with omega-3 fats, including:
- Fewer asthma symptoms22
- Brain23 and eye24 development
- Reduced risk of Parkinson's disease25
- Reduced risk of multiple sclerosis26
- Reduced risk of depression27,28
Differences Between Plant and Animal Based Omega-3
Although omega-3 fat may be found in plant and animal sources, it's the animal-based sources that have higher levels of EPA and DHA. Plant-based sources such as raw nuts and seeds are high in alpha-linolenic acid (ALA). These are shorter chain omega-3 fats and are also essential since your body cannot make them.29
While all three are needed to keep you healthy, it's important to know that plant-based sources are higher in ALA and animal-based sources are higher in EPA and DHA.30
Your body is able to make some EPA and DHA from the short chain ALA in plant-based sources, but it does so inefficiently. The conversion is not enough for optimal brain growth and development or to reduce the inflammatory effects of omega-6 in your body.
Choose Krill Oil Over Fish Oil for Omega-3
The best omega-3 supplement is from an animal-based source. Krill oil and fish oil provide both EPA and DHA, but while krill is sustainable, fish oil has a greater potential for contamination. In addition, fish oil has a higher risk of oxidative damage that can occur during processing and after you open the bottle.31
In an analysis of fish oil available over the counter in Canada, researchers analyzed 171 supplements from 49 brands.32 The scientists found 50% of the samples exceeded one measurement of oxidation and 39% exceeded what is considered safe by international standards.
Another research team found that 25.9% of fish oil tested in the U.S. had more than twice the recommended levels of lipid peroxides and 92.5% had measurable amounts of mercury.33 It's important to remember that these tests were done on supplements before the bottles were opened, which increases exposure to oxygen and subsequent oxidative damage.
Krill oil is not as unstable because it also contains astaxanthin which reduces oxidative damage. In addition to a lower rate of contamination, krill oil is far more potent than fish oil. In one study,34 participants who took krill oil required only 62.8% of the amount of those taking fish oil to achieve the same results.
The Vitamin D and Omega-3 Relationship
Vitamin D and omega-3 have several things in common.35 They both play important roles in your overall and cardiovascular health. Additionally, there is evidence that most people are deficient in both.
This sparked the VITAL study,36 in which researchers at Brigham and Women's Hospital began evaluating the effects of daily dietary supplementation of vitamin D3 or omega-3 fatty acids. They are interested in learning whether these dietary additions may reduce the risk that someone without cardiovascular disease or cancer will develop it in the future.
The study includes 25,871 men and women across the U.S.; data are still being compiled and evaluated. In a related study,37 co-supplementation was found to affect inflammation and oxidative stress in women who had gestational diabetes.
Our staff recently took an omega-3 and vitamin D3 challenge during which they used the dual test kit offered by GrassrootsHealth, an independent research organization that we partner with. Participation in the project is giving researchers the opportunity to learn more about how these two essential nutrients function together.
The results also help you determine how you can make changes affecting your health. Working with this Research Institute, you can get answers to not only what your test levels are, but also determine whether or not your actions are working for you. The tests are done at home, are completely private, and require no doctor or lab visit. Once your sample and questionnaire are mailed, your results are usually ready within 10 to 20 days after the lab receives your sample.
I offer this test kit simply as a convenience and courtesy as I don't benefit or participate in the test in anyway. Proceeds from the sale go directly to GrassrootsHealth.38 However, I feel so strongly about how deficiencies in omega-3 and vitamin D may affect health, I have encouraged our staff to use this project as a means of identifying deficiencies and determining their best supplementation levels.