A. The sample types we use (red blood cell / dried blood spot vs plasma / phospholipids)
Each of these sample types has a unique fatty acid profile, so you cannot compare the EPA+DHA level in RBCs to the EPA+DHA level in plasma, or in plasma phospholipids – the numbers will be quite different, even from the same lab. So regardless of which lab you choose to work with, you should always order the same type of test if you want to be able to track trends in the same patient over time. At OmegaQuant, we offer a RBC profile and a whole blood (dried blood spot) profile, and from either one you can get our branded metric, the HS-Omega-3 Index®. We do not offer serum or serum phospholipid assays because we believe that the RBC – since it’s a cell – provides the best reflection of tissue omega-3 fatty acid status. In addition, there is considerably more day-to-day variation in the plasma tests than in the RBC – (or whole blood) – based tests.

B. The uniqueness of the specific method we use
Second, even if you order the RBC-based assay from two different labs, there is no guarantee whatever that you’ll get the same answer. That’s a big problem. The reason is that, unlike serum cholesterol or glucose or calcium, there is no standardized method (i.e., internationally recognized gold standard) to which all labs must peg their assays. There is no standard test material to which all labs are required to conform. So your EPA+DHA, for example, might be 6.7% in Lab A and 5.2% in Lab B. Which one is “right?” We don’t know what “right” is because there is no formal standard. At OmegaQuant, the specific method we use has more research behind it than any other commercially-available test and many more studies will be published in the coming years. A significant advantage of the HS-Omega-3 Index test is the ability to correlate it to clinical outcomes from major epidemiological and interventions studies (see below for “Research behind the test”)

C. The number of fatty acids reported in the profile
In addition to the HS-Omega-3 Index, we also provide, at no additional charge, a complete fatty acid profile including 4 omega-3 fatty acids, 7 omega-6 fatty acids, 4 monounsaturated fatty acids, 6 saturated fatty acids, 3 groups of trans fatty acids, 5 composites (group sums), and 2 ratios (see below). Other ratios or groups of fatty acids can be calculated from these. But beyond these 26 fatty acids, there are still others (very minor components) that can be detected in both RBCs and in whole blood, and some labs will report these as well. It is our view at OmegaQuant that it is possible to provide too much information, and hence we draw the line at these 26, and in many respects, even this is more than can practically be addressed. We provide them as a courtesy to those clients who want to know. Sometimes “less is more” and we believe that applies here.

D. The ratios included in the profile
As noted above, we provide two fatty acid ratios: the omega-6/omega-3 and AA/EPA. Although we include these values, we believe that the HS-Omega-3 Index is, by far, the single most important (and actionable) component of our report. These other fatty acids and ratios are provided as a courtesy and because some practitioners find them useful. We would suggest that for the dried blood spot assay, the omega-6/omega-3 ratio should be 4.6 or less, and the AA/EPA ratio should be 9 or less. For the red blood cell assay, the omega-6/omega-3 ratio should be 2.6 or less, and the AA/EPA ratio should be 15 or less.

E. The use of “reference” or “normal” ranges
Included with each the 5 classes of fatty acids are “reference ranges.” Reference ranges should not be confused with “normal” or “optimal” or “target” values. The reference range is provided simply to give an idea of how these values compared to a large number of others taken from a relatively healthy population. In the case of the RBC assay, the reference range was taken from approximately 3200 participants in the Framingham Offspring study, whose average age was 67 years old. In the case of the dried blood spot assay, the reference range was taken from approximately 1000 participants in the Heart and Soul study, also 67 years of age on average, but all with a history of heart disease. In both cases, the reference range encompasses 99% of the individuals in their respective populations. Although “average,” these are not necessarily “optimal” levels, i.e., target levels or levels that one should to attempt to achieve. The only result for which we feel justified in providing an actual target or optimal level is the HS-Omega-3 Index since it has received undergone the most research. As the research in this area matures, we will recommend new “target” values for other fatty acids or ratios when we believe that they have been adequately validated.

F. The provision of dietary recommendations to correct deviations from “normal”
As noted above, we provide reference ranges for general information only, not to suggest or guide changes in diet. We do not believe that the research has advanced to the point where we can tell people who have a below (or above) “average” level of any given fatty acid class that they should try to change it. First, since most fatty acid levels in the blood are not influenced by diet but are established by internal genetics and metabolism, even attempting to alter a fatty acid level by dietary change would be largely futile. Secondly, we don’t have the data at present to show that even if one could change fatty acid levels (again, except for the HS-Omega-3 Index and trans fatty acids), it would benefit them to do so. So until further research convincingly demonstrates that raising or lowering a certain fatty acid or class is beneficial or not, we will take the conservative approach of simply giving each client the numbers, and they can track them as they wish.

Clearly, we are very comfortable with recommending specific targets for the HS-Omega-3 Index® because the research supporting a target of 8% is strong, and we know that you can specifically raise the Index by eating more omega-3. We don’t, however, know exactly how much EPA+DHA any particular person should be told to take to achieve the 8% target. People differ, and so each person’s response to supplemental omega-3s will vary. Just like one cannot predict how much serum cholesterol will go down when a patient is placed on statins, we cannot accurately predict how the HS-Omega-3 Index® will respond to an increased intake; it must be individually tested. (See Question 2).

G. The research behind the test
Dr. Harris has been doing research in omega-3s for 30 years, and has over 80 published research papers in this field. He, along with his colleague Clemens von Schacky, MD, a cardiologist from Munich, was the first to propose the Omega-3 Index as an independent risk factor for heart disease. More importantly, currently Dr. Harris is the Principal Investigator for and is using the HS-Omega-3 Index test in two major epidemiological studies, both funded by the National Institutes of Health (NIH): the Framingham Heart Study and the Women’s Health Initiative’s Memory Study. In addition, he will be doing the blood analyses in the newly announced $20M, 20K-subject “VITAL” study testing omega-3 and vitamin D for CHD and cancer prevention. Dr. Harris is using the same method in at least 8 additional clinical studies being funded by the NIH.

H. The clinical applicability of the test
Because of the research foundation supporting the HS-Omega-3 Index, its clinical utility will continue to grow and mature as the results of these new studies are published. Health care providers and consumers alike want their results to be comparable to those published in the mainstream medical literature. If high or low risk for disease X is defined by a particular HS-Omega-3 Index value as derived from these research studies, then only by using this specific test can you be sure that yourlevel of risk is accurately predicted; a value from another lab may or may not give you a clinically-useful estimate of risk. It is for these reasons that the Cooper Aerobics Center (Dallas, TX) selected OmegaQuant as their sole provider for fatty acid testing.

At OmegaQuant, we primarily offer the HS-Omega-3 Index test for researchers and re-sellers. Healthcare providers wishing to use this test in patient care should contact customer service at Health Diagnostic Laboratory (HDL, located in Richmond, VA, 804-343-2718) to set up an account. HDL performs the HS-Omega-3 Index Test. For individuals wishing to have the test performed directly by OmegaQuant, the price is $199.95. Contact Customer Service at 1-800-949-0632 or send an inquiry to info@omegaquant.com. Researchers, please contact Customer Service for a price quote for blood, plasma, or tissue fatty acid tests.

No. There is no way to predict – for any given person – what his/her HS-Omega-3 Index will be just by knowing how much fish they eat or how many capsules they take. Individual differences in metabolism, absorption, and genetics make it impossible to predict with certainty how a given person will respond to supplements.

The only way is to directly measure the HS-Omega-3 Index®.

The target HS-Omega-3 Index is 8% and above, a level that current research indicates is associated with the lowest risk* for death from CHD. This is also a typical level in Japan, a country with one of the lowest rates of sudden cardiac death in the world. On the other hand, an Index of 4% or less (which is common in the US) indicates the highest risk*. At present, there is no reason to suggest that the target should be different for men vs. women, or for different age groups. Whether there is an upper limit of safety for the Index is not clear, but there is likely a value above which there is not likely to be any additional health benefit. Further research will help define this level.

*In this context, “risk” refers only to that associated with differing levels of omega-3 fatty acids. Risks associated with other factors such as cholesterol, blood pressure, diabetes, family history of CHD, smoking, or other cardiac conditions are completely independent of and not influenced by omega-3 fatty acids. All risk factors – including the HS-Omega-3 Index—should be addressed as part of any global risk reduction strategy.

Increase your intake of EPA+DHA. The amount you would need to take in order to raise your HS-Omega-3 Index into the target range (>8%) depends in part on your starting level, but it cannot be predicted with certainty as described above. Nevertheless, if your HS-Omega-3 Index is between 4% and 8%, we would recommend that you increase your current EPA+DHA intake by ½ -1 gram (500 – 1000 mg) per day. This can be accomplished in two ways: eating more oily fish and/or taking fish oil supplements. On the other hand, if it is less than 4%, our recommendation would be that you raise your intake by 1-3 g (1000 – 3000 mg) per day. Although this can be accomplished by eating more oily fish, fish oil supplements are usually necessary to achieve this level of EPA+DHA intake.

In our experience, to increase the HS-Omega-3 Index by 4%, one would need to take about 25 g EPA+DHA-weeks. That means taking 1 g of EPA+DHA per day for 25 weeks, or 2 g/d for 12.5 weeks or 3 g/d for about 8 weeks. In other words it’s a combination of dose and time. This calculation probably cannot be extrapolated to extreme conditions; for example, 25 g/d x 1 week or 0.1 g/d x 250 weeks may not achieve the same effect.

In North America, the test is performed by OmegaQuant®, Sioux Falls, SD. In Europe, the test can be obtained from our sister laboratory, OmegaMetrix. As other labs around the world become licensed to offer the HS-Omega-3 Index test they will be listed on our website.

Once the sample is received at OmegaQuant, the results will be available on-line within 3 working days.

The other class of fatty acids that, like the omega-3 fatty acids, is largely controlled by dietary habits is the trans fatty acids. There has been much about these “bad” fatty acids in the media in recent years, and some cities have actually banned these fatty acids from restaurants. You can learn more about saturated and trans fatty acids here. With respect to defining a “healthy” target value, this has not received much attention, and thus any recommendations should be considered tentative. At OmegaQuant, we are in the process of defining, based on our test, what a good level should be, and this will be posted on our website once we are comfortable with the science behind it. But even without a target value, you can use the “total trans fats” result on your Full Fatty Acid report to track changes in your own personal trans levels as you begin to eat a healthier diet.

The HS-Omega-3 Index® is an accurate, precise and validated measure of your red blood cell omega-3 level. The assay is reproducible, linear across the physiological range, and highly responsive to changes in omega-3 intake, even when measured in a dried blood spot. Intra-individual variability in the HS-Omega-3 Index® is very low. For more information, click here.

For the RBC Test (obtained directly from a blood tube) overnight fasting is not necessary. In general the same is true for the dried blood spot test, the only exception being the situation where an individual might take a fish oil supplement 2-6 hours before taking the blood test. In this case, the EPA+DHA value from the dried blood spot will be artificially inflated; therefore, the test should be done at least 12 hours after the last dose of fish oil.

Whole blood and RBCs are different starting materials and the EPA+DHA content of each is different, but highly correlated. Based on multiple experiments, we have derived a mathematical equation that converts the DBS EPA+DHA value into the corresponding RBC value (which is the HS-Omega-3 Index). Therefore, the sum of EPA and DHA in the DBS report will usually be slightly different from the HS-Omega-3 Index.

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