Measuring the Omega-3 Index: the one blood value hardly any doctor checks
Do not guess. Measure. The Omega-3 Index shows how well your cell membranes are actually supplied. And it often shows something different from what the capsule on your kitchen table suggests.
We have been recommending omega-3 for decades without checking whether it actually arrives. A capsule is an amount, not a result. Only the blood value turns an assumption into a decision.
I bet you know this scene. There is a tin of fish oil in the kitchen cupboard. You have been taking it for months, most days at least. Sometimes you wonder whether it does anything. And then you put it back and think: it will be fine.
That is not carelessness. That is a completely normal reaction to a situation we would hardly accept with any other laboratory value. For iron we measure ferritin. For vitamin D we measure 25-OH-D. For thyroid we measure TSH. For omega-3 we take a capsule and hope.
Yet since 2004 there has been a value that could fill exactly this gap. It is called the Omega-3 Index. And it appears in hardly any routine laboratory panel.
What to expect here
- What the Omega-3 Index measures and why in red blood cells
- Where the target range of 8 to 12 percent comes from
- Why the same capsule produces two values in two people
- How Germany compares internationally
- The four KPNI lenses on the same value
- What the index cannot do, named openly
- When caution is appropriate, including bleeding risk
- How to plan a follow-up measurement sensibly
What the Omega-3 Index actually measures
Imagine each of your cells as a house. The outer wall of this house is not made of stone, but of fat. More precisely: of a double layer of fat molecules, with receptors, channels and pumps sitting in it like windows and doors.
How flexible this wall is depends on which fatty acids were built into it. Saturated fatty acids are straight and lie tightly packed, like boards in a stack. The long chain omega-3 fatty acids EPA and DHA have several kinks. They create space in between. They make the wall supple.
The Omega-3 Index measures exactly that: the share of EPA plus DHA among all fatty acids in the membrane of your red blood cells, expressed as a percentage.
Why red blood cells of all things? Because they live for around 120 days. Their membrane is therefore a long term memory. It does not show what you ate yesterday, but how you have been supplied over months. A value in serum, by contrast, fluctuates with every meal and can mislead you.
William Harris and Clemens von Schacky proposed in 2004 in Preventive Medicine that the EPA plus DHA content in red blood cells be considered a risk marker in its own right for death from coronary heart disease. They combined their own laboratory data with the results of already published prevention studies.
Their observation: an index of around 8 percent or higher went along with the most favourable risk profile, an index of 4 percent or below with the least favourable one. For you that means: the target range you read about everywhere today does not come from marketing, it comes from this series of observations.
Harris WS, von Schacky C. Prev Med. 2004;39(1):212-220. DOI: 10.1016/j.ypmed.2004.02.030And now you know why I would rather look at a tube of blood than at a tin.
Where the target range of 8 to 12 percent comes from
A target value without a rationale is a claim. So here are the three data sets this corridor rests on.
The four categories as used in the literature
This classification comes from the omega-3 world map 2024. Individual research groups name 8 to 11 percent as the target range. The spread is a scientific discussion, not a contradiction.
Harris, Del Gobbo and Tintle re-analysed data from 10 prospective cohorts in 2017 in Atherosclerosis to check whether the originally proposed cut off values hold up. The mean index across all cohorts was 6.1 percent.
Per standard deviation of higher index, the risk of fatal coronary events came with a hazard ratio of 0.85. From this the authors estimated: with a shift from 4 to 8 percent, the risk would have been around 30 percent lower. Important for you: these are observational data, not an intervention trial. They describe an association, they do not prove a cause.
Harris WS, Del Gobbo L, Tintle NL. Atherosclerosis. 2017;262:51-54. DOI: 10.1016/j.atherosclerosis.2017.05.007In 2021 Nature Communications published a pooled analysis of 17 prospective cohort studies. Over a median of 16 years of follow-up, 15,720 deaths occurred among 42,466 people.
People in the top fifth of long chain omega-3 levels had a 15 to 18 percent lower risk of death from any cause than people in the bottom fifth. Similar patterns showed for cardiovascular death and cancer death. For plant based alpha linolenic acid, no such association was found. For you that means: if anything counts here, it is EPA and DHA, not omega-3 as a collective term.
Harris WS, Tintle NL, Imamura F et al. Nat Commun. 2021;12(1):2329. DOI: 10.1038/s41467-021-22370-2The Omega-3 Index is not a grade for your diet. It is a position fix. A low value does not mean you did something wrong. It means that your intake and your requirement currently do not match.
And that is good news. Because a position can change. A grade stays.
Two capsules a day, index at 4 percent
When discipline meets a dose that is too small
I know this pattern very well. Someone comes to the practice and brings a complete list. Two fish oil capsules daily, for over a year, in the morning with breakfast, not a single day missed. The question is: is that enough?
We measure the Omega-3 Index. The result is 4 percent. So at the lower end of what the literature classifies as very low.
The front of the tin stated an amount of fish oil. The back stated how much of that was actually EPA and DHA. Between those two numbers there is a factor that hardly anyone works out. Add to that body weight, starting point and absorption in the gut.
I cannot claim causality here and only document the temporal sequence: after an adjusted intake and a control measurement in the same laboratory, the value was clearly higher in the following quarter. Whether and how that is mirrored in how someone feels is a second question, and nobody can answer it from a laboratory value alone.
The lesson: it is not loyalty to the capsule that decides, but the amount of EPA and DHA that arrives in this particular body.
Without measurement, every omega-3 recommendation is an estimate with very wide scatter. With measurement it becomes a decision with feedback.
Why the same capsule produces two different values
Here it gets interesting. And here lies the reason why I consider blanket recommendations problematic.
Michael Flock and colleagues randomised 115 healthy adults in 2013 in the Journal of the American Heart Association and gave them 0, 300, 600, 900 or 1800 milligrams of EPA plus DHA daily over around five months. The Omega-3 Index was measured before and after.
The index rose in a dose dependent way. Dose alone explained 68 percent of the variability in response. Calculated as dose per kilogram of body weight it was 70 percent. Adding baseline value, age, sex and physical activity brings you to 78 percent.
For you that means: around one fifth of the result remains individual and unpredictable. This is why the follow-up measurement is not a luxury, but the actual core of the method.
Flock MR, Skulas-Ray AC, Harris WS et al. J Am Heart Assoc. 2013;2(6):e000513. DOI: 10.1161/JAHA.113.000513An Australian research group gave 160 healthy adults fish oil over 16 weeks in 2014 in Nutrients, in part combined with a multivitamin. The EPA content in red blood cells rose under the higher fish oil dose, the DHA content remained unchanged on average.
The authors describe considerable individual variability. Women showed higher values on average at the end than men. For you that means: even with an identical capsule, identical duration and an identical study protocol, people do not end up at the same point.
Pipingas A, Cockerell R, Grima N et al. Nutrients. 2014;6(5):1956-1970. DOI: 10.3390/nu6051956What this means for the large intervention trials
You may have read that omega-3 studies have produced contradictory results. That is true. Part of the explanation could lie in the methodology.
A review from 2023 in the Internal Medicine Journal argues that many of the large trials worked with less than 1 gram of EPA and DHA per day and neither recorded the blood level at baseline nor titrated to a target range. If you randomise by dose only and do not analyse by the level actually reached, you could dilute an effect that is present.
That is a plausible hypothesis, not a proof. It comes from authors who are close to the index. It still deserves an honest examination, because it is methodologically comprehensible.
Hamilton-Craig C, Kostner K, Colquhoun D, Nicholls SJ. Intern Med J. 2023;53(12):2330-2335. DOI: 10.1111/imj.16283| Study | Daily dose of EPA plus DHA tested | Duration | Observation |
|---|---|---|---|
| Flock 2013, n=115 | 0, 300, 600, 900, 1800 mg | approx. 5 months | Dose dependent rise of the index |
| Pipingas 2014, n=160 | 3 g or 6 g fish oil daily | 16 weeks | EPA rise, DHA unchanged on average |
| Skulas-Ray 2015, n=115 and n=28 | up to 1800 mg and up to 3400 mg | 5 months and 8 weeks | Dose dependent rise of DPA as well |
| Lane 2021, scoping review | plant oils versus algal oil | varied | Only algal oil raised the index |
And now you know why with omega-3 I do not start with a dose, but with a number.
Where Germany stands in international comparison
When a value is low in almost everyone, at some point people consider it normal. That is a thinking error I come across in many areas. Normal and average are not the same thing.
Jan Philipp Schuchardt and an international team pooled data from seven countries in 2022, a total of 167,347 people from the USA, Canada, Italy, Spain, Germany, South Korea and Japan.
Only the cohorts from Alaska, South Korea and Japan were in the desirable range. Spain was moderate. The cohorts from the USA, Canada, Italy and Germany were classified as low, meaning above 4 to 6 percent. For you that means: a value around 5 percent is unremarkable in this country, but it lies clearly below the discussed target range.
Schuchardt JP, Cerrato M, Ceseri M et al. Prostaglandins Leukot Essent Fatty Acids. 2022;179:102418. DOI: 10.1016/j.plefa.2022.102418In 2024, Progress in Lipid Research published the updated worldwide stocktaking. It included 328 studies with 342,864 people from 48 countries and regions.
The authors' conclusion: in most countries the Omega-3 Index is low to very low. Countries such as Iran, Egypt and India stood out particularly. Important for context: the data come mainly from study cohorts, not from representative population samples. They are a strong signal, but not official statistics.
Schuchardt JP, Beinhorn P, Hu XF et al. Prog Lipid Res. 2024;95:101286. DOI: 10.1016/j.plipres.2024.101286"When a value is low in almost everyone, it is not normal. It is average. And average is a description of how we live, not a biological goal."
Shukri Jarmoukli, ViveCura BerlinFour lenses on the same value
In clinical psychoneuroimmunology I look at a topic through four lenses: nervous system, immune system, metabolism, hormonal system. With the Omega-3 Index they converge at one point, namely the cell membrane.
Nervous system
DHA is not just any fat in the brain. It is building material. Grey matter and synapses contain particularly high proportions. A supple membrane at the synapse is the precondition for receptors to change shape and pass signals on.
Tan and colleagues compared the DHA content in red blood cells with brain MRI and cognitive tests in 1,575 dementia free participants of the Framingham study in 2012 in Neurology.
People in the lowest quartile had smaller total brain volumes and performed more weakly in tests of visual memory, executive function and abstract reasoning. For you that means: there is a striking association. Whether low DHA contributes to smaller volumes, or whether both share a common cause, is something a cross sectional study cannot answer.
Tan ZS, Harris WS, Beiser AS et al. Neurology. 2012;78(9):658-664. DOI: 10.1212/WNL.0b013e318249f6a9An analysis from 2022 in Neurology examined 2,183 people with a mean age of 46 years, all without dementia and without a history of stroke.
A higher Omega-3 Index was associated with larger hippocampal volume and better results in abstract reasoning. The authors themselves describe their results as exploratory. For you that means: the topic does not only concern old age, but it is not yet an established causal chain either.
Satizabal CL, Himali JJ, Beiser AS et al. Neurology. 2022;99(23):e2572-e2582. DOI: 10.1212/WNL.0000000000201296Immune system
EPA and DHA are the starting material for messengers that actively bring inflammatory processes to an end. In the field they are called resolvins and protectins. The image for this: inflammation is the fire brigade. And these molecules are the instruction to roll the hoses back up. Without building material, the order to clean up is missing.
McBurney, Tintle and Harris examined 25,485 people without inflammation and without anaemia in a clinical laboratory data set in 2021. They compared the Omega-3 Index and red blood cell distribution width, a routine value from every blood count.
Both measures were inversely related, in women and in men, also after adjustment for age, sex, body mass index and CRP. The authors concluded that an index above 5.6 percent could contribute to maintaining normal structure and function of red blood cells. For you that means: the index is not an abstract laboratory value, it has a visible link to the nature of your cells.
McBurney MI, Tintle NL, Harris WS. Prostaglandins Leukot Essent Fatty Acids. 2021;176:102376. DOI: 10.1016/j.plefa.2021.102376Metabolism
Insulin docks onto a receptor that sits in the cell membrane. How flexible this membrane is can influence how the signal is passed on. That is the mechanistic idea behind the link between fatty acid pattern and metabolism.
A meta-analysis from 2021 summarised eight case control studies, with 1,357 people with type 2 diabetes and 1,616 control participants. The Omega-3 Index was significantly lower in the diabetes group.
Very important for context: heterogeneity between the studies was extremely high, the authors report an I squared of 99 percent. And case control studies cannot say what came first. It could be biologically plausible that the membrane plays a part. It is not proven.
Ma MY, Li KL, Zheng H et al. Prostaglandins Leukot Essent Fatty Acids. 2021;174:102361. DOI: 10.1016/j.plefa.2021.102361Hormonal system
Every steroid hormone has to pass a membrane in the end, or bind to a receptor that sits in a membrane. And pregnancy is the phase of life in which the requirement rises most clearly, because the developing brain incorporates DHA.
Clemens von Schacky reviewed the evidence for pregnancy and breastfeeding in 2020 in Nutrients. Pregnant women in Germany were on average below the discussed target range, with very wide scatter between individuals. Notably, the values were largely independent of whether supplements were taken.
The author explicitly points to the other direction as well. A very high intake or very high levels can also come with problems, naming a tendency to bleed and a prolonged duration of pregnancy. For you that means: a target range has an upper limit, and for good reason.
von Schacky C. Nutrients. 2020;12(4):898. DOI: 10.3390/nu12040898Omega-3 is not a heart remedy, not a brain remedy and not a joint remedy. It is building material for every single cell membrane in your body.
That is why the same fatty acids show up in such different fields of research. Not because they could do everything, but because they are built in everywhere. And that is why a membrane value is something different from a capsule recommendation.
How to measure properly and why the method matters
A value is only as good as the procedure behind it. And this is exactly where the most honest criticism of the Omega-3 Index lies.
Clemens von Schacky describes in a review from 2020 that the index is offered by many laboratories worldwide, but that even small differences in the analytical procedure lead to large differences in the result. Nevertheless results are often compared against the target range that was defined for one particular standardised procedure. He calls this an ethical problem and demands standardisation.
A second interesting point from the same paper: no human being has an index below 2 percent. So there is a biological minimum that can apparently be approached but not fallen below.
von Schacky C. Proc Nutr Soc. 2020;79(4):381-387. DOI: 10.1017/S0029665120006989In practical terms for you: baseline and control measurement belong in the same laboratory with the same method. A value from laboratory A and a value from laboratory B do not make a reliable curve over time.
A paper from 2018 in Lipids compared the classical gas chromatographic procedure with a faster mass spectrometric method for determining erythrocyte fatty acids.
Both methods correlated very closely for the Omega-3 Index, with an R of 0.993, and showed no systematic bias. For you that means: technically good routes exist. The sticking point is not the physics, but the lack of uniform application.
Alqarni A, Mcintyre KJ, Brown SHJ et al. Lipids. 2018;53(10):1005-1015. DOI: 10.1002/lipd.12108What belongs to a sensible measurement
- Determination in erythrocytes, not in serum or plasma
- Standardised, documented analytical procedure
- Baseline measurement before any supplementation
- Control measurement after roughly three to four months
- Same laboratory, same method for the follow-up
- Statement of the laboratory's reference and target range
What the index does not do
- It does not replace ferritin or thyroid values
- It says nothing about vitamin D or vitamin B12
- It is not an inflammatory marker
- It is not a cardiovascular diagnosis
- It does not explain every symptom
- It is no substitute for a medical examination
Why DPA is not counted
Alongside EPA and DHA, the blood contains a third long chain omega-3 fatty acid, docosapentaenoic acid or DPA for short. It deliberately does not appear in the index.
von Schacky and Harris set out in 2018 why DPA was not included in the index. In epidemiological analyses, DPA in erythrocytes could predict neither the risk of all cause mortality nor of sudden cardiac death, and it did not improve prediction even when added to EPA and DHA.
For you that means: if a laboratory report sells you a sum of three fatty acids as the Omega-3 Index, that is not the same as the validated value. Ask what exactly was added up.
von Schacky C, Harris WS. Prostaglandins Leukot Essent Fatty Acids. 2018;135:18-21. DOI: 10.1016/j.plefa.2018.06.003For whom the measurement is particularly obvious
Not every person needs every laboratory value. There are, however, constellations in which an estimate is especially unreliable.
Vegetarian or vegan
Plant oils supply alpha linolenic acid, not EPA and DHA. A scoping review from 2021 found that high dose flaxseed or echium oil did not raise the index, while microalgae oil did so in all studies considered. Guessing is particularly risky here.
Algal oil Limited conversion rateNo fish on the plate
A dose response meta-analysis from 2022 found the possible benefit of fish consumption to be exhausted at around two portions per week. Anyone clearly below that and not supplementing has, statistically speaking, little chance of a value in the target range.
Intake FishPregnancy and wanting to conceive
The requirement rises, and German data show wide individual scatter, largely independent of intake. At the same time, particular caution towards the upper end applies here. This situation belongs in medical care, not in self management.
Higher requirement Mind the upper limitAlready supplementing without any check
If you have been taking capsules for months and do not know where you stand, measurement is the only way to answer that question. It can also show that you have long been in the target range and need to change nothing.
Follow-up Downwards possible too- You take anticoagulant medication, for example vitamin K antagonists, direct oral anticoagulants or platelet inhibitors
- Surgery or a larger procedure is planned
- There is a known clotting disorder or a tendency to bleed
- You are pregnant or breastfeeding
- There is a fish allergy or an allergy to seafood
- There is severe liver or kidney disease
The ViveCura way: measure, adjust, measure again
I think little of recommending a supplement and then never speaking about it again. A value without a course over time is a snapshot. A course without adjustment is statistics.
Baseline value before the first capsule
Without a starting point there is no course over time. Measuring before you start shows whether there is a gap at all. In some cases the value is already in the target range, and the most obvious recommendation is then: change nothing.
Read the back of the tin, not the front
The front states the amount of fish oil. What matters is the declared amount of EPA and DHA per portion. Between those two numbers there is often a factor that changes the whole calculation. Details on purity and oxidation stability belong here as well.
Take individual factors into account
The dose response trial showed that body weight, baseline value, age, sex and physical activity explain a large part of the response. A recommendation that ignores these factors ignores 78 percent of the known explanation.
Check after three to four months
The membrane of red blood cells needs time. Intervention studies typically measured again after 16 weeks to 5 months. A check after two weeks says little. A check after a quarter says a lot.
Adjust, in both directions
If the value is in the target range, the amount can stay the same or go down. If it is far below, an upward adjustment can be considered. Both are medical decisions, because medication, coagulation and pre-existing conditions play into it.
What I also look at before talking about omega-3
- Ferritin and transferrin saturation: the most commonly overlooked reason for exhaustion. A membrane value does not explain iron deficiency.
- Thyroid: TSH, free T3, free T4 and, where suspected, TPO antibodies.
- Vitamin D and vitamin B12: two values that are often low at the same time and can accompany similar complaints.
- Inflammatory markers and blood count: also because red blood cell distribution width is linked to the index.
- Blood sugar and HbA1c: metabolism and membrane quality are connected.
- Dietary history: how often fish, which oils, how much processed food. Without this information, every value is a riddle without context.
Three levers for this week
First: take your omega-3 tin out of the cupboard and read the back. Note down how many milligrams of EPA and DHA are in a daily portion. That single number is the beginning of every sensible discussion.
Second: keep track for seven days of how often oily sea fish lands on your plate. Not fish in general, but salmon, mackerel, herring, sardine. You may be surprised how far self image and reality can drift apart.
Third: if you have been supplementing for months and do not know where you stand, raise the idea of determining your Omega-3 Index. One value, measured in the same laboratory, repeatable after a quarter. That is the difference between a habit and a decision.
You do not have to believe that omega-3 is arriving in your body. You can look it up. And that is the real progress in this value.
And now you know why with me the blood value comes before the capsule.
Frequently asked questions about the Omega-3 Index
What exactly is the Omega-3 Index?
The Omega-3 Index is the share of the two marine omega-3 fatty acids EPA and DHA among all fatty acids in the membrane of your red blood cells, expressed as a percentage. It was proposed in 2004 by William Harris and Clemens von Schacky as a possible risk marker. Here is the clever part: red blood cells live for around 120 days. The value therefore does not reflect what you ate yesterday, but your supply over months. That makes it fundamentally different from a plasma measurement, which fluctuates strongly and depends on your last meal.
Which Omega-3 Index is a good one?
The literature discusses a target range of 8 to 12 percent, and depending on the research group also 8 to 11 percent. Values below 4 percent are considered very low. An analysis of 10 prospective cohorts estimated that the risk of fatal coronary events would have been around 30 percent lower with a shift from 4 to 8 percent. Important for context: these are observational data. They show an association, not proof of cause and effect.
Why does my family doctor not order the Omega-3 Index?
This is not a reproach towards colleagues. The Omega-3 Index is not part of any routine laboratory panel, it is not covered by statutory health insurance, and it does not appear in most guidelines as a parameter to steer by. On top of that comes a methodological problem: even small differences in the analytical procedure lead to clearly different results, which is why experts have been calling for standardisation for years. As long as a value is neither standardised nor reimbursed, it rarely finds its way into routine care. That does not make it worthless, it makes it a value that needs explaining.
How is the Omega-3 Index measured?
Measurement takes place in the red blood cells, not in serum. Classically this is done by gas chromatography after a defined preparation procedure. Dried blood spot methods using a few drops from the fingertip also exist. What matters is that the same standardised procedure is always used, because values from different methods are not directly comparable. In practical terms for follow-up: baseline and control measurement in the same laboratory with the same method.
Why are two omega-3 capsules often not enough?
Because two capsules are an amount, not a result. In a randomised dose response trial with 115 healthy adults, the index rose in a dose dependent way over five months, testing 0, 300, 600, 900 and 1800 milligrams of EPA plus DHA per day. Dose alone explained 68 percent of the variability in response. Calculated as dose per kilogram of body weight it was 70 percent. Together with baseline value, age, sex and physical activity the figure reached 78 percent. Put differently: two people taking the same capsule do not end up at the same value.
How long does it take for the Omega-3 Index to change?
Red blood cells are constantly renewed, their mean lifespan is around 120 days. The membrane therefore needs time before it reflects a changed intake. Intervention studies typically chose periods of around 16 weeks to 5 months before measuring again. A check after two weeks says very little. A realistic window for follow-up measurement is three to four months.
Are flaxseed oil, chia or walnuts enough to raise the index?
Plant sources supply alpha linolenic acid, not EPA and DHA. The body can convert only a limited amount. A scoping review from 2021 examined intervention studies on plant oils and found that high dose flaxseed or echium oil did not raise the Omega-3 Index, and in individual studies even accompanied lower values. Oil from microalgae, by contrast, raised the index in all studies considered. For people living vegetarian or vegan, algal oil is therefore the more obvious option. And the index is the only way to check this instead of hoping.
How does Germany compare on the Omega-3 Index?
Rather weakly. In an analysis of data from seven countries covering 167,347 people, the German cohort was classified as low, meaning above 4 to 6 percent. The updated omega-3 world map from 2024, with 328 studies and 342,864 people from 48 countries and regions, paints a similar picture: in most countries the index is low to very low. These figures come mainly from study cohorts, not from representative population samples. They are a signal, not official statistics.
Can the Omega-3 Index be too high?
The discussed target range has an upper limit for good reason. In a review on pregnancy and breastfeeding, the author explicitly points out that a very high intake or very high levels can also come with problems, naming a tendency to bleed and a prolonged duration of pregnancy. Anyone taking blood thinning medication, facing surgery or living with a known clotting disorder should therefore discuss omega-3 intake with a doctor. A target range is a corridor, not a competition to go higher.
What does a low Omega-3 Index say about my brain?
There are striking observational data, but no proof. In the Framingham cohort, participants with the lowest DHA values in red blood cells had smaller total brain volumes and weaker results in tests of visual memory, executive function and abstract reasoning. A later analysis of 2,183 people in midlife found higher index values associated with larger hippocampal volume and better abstract reasoning. Both are cross sectional findings. They cannot show what is cause and what is consequence.
Does the Omega-3 Index replace other blood values?
No, and that matters. The index says something about your fatty acid supply, nothing else. If you are tired, ferritin, thyroid, vitamin D, vitamin B12, a full blood count and blood sugar belong on the table just as much. A good Omega-3 Index does not rule out iron deficiency. A poor Omega-3 Index does not explain every symptom. It is one piece of a picture that only makes sense in context.
Read on in the ViveCura guide
The Omega-3 Index never stands alone. These topics are physiologically connected to it.
Supplements
What makes sense and what does not
You are hereVitamin D
Taking it properly, with magnesium and K2
Iron deficiency
Ferritin, infusions, functional deficiency
Iron
The most overlooked reason for fatigue
Nutrition
Fatty acids, protein, real food
Hormones
Cortisol, thyroid, sex hormones
Burnout
When exhaustion no longer goes away
Medicinal plants
Phytotherapy with evidence and limits
Sources
- Harris WS, von Schacky C. The Omega-3 Index: a new risk factor for death from coronary heart disease? Prev Med. 2004;39(1):212-220. DOI: 10.1016/j.ypmed.2004.02.030 [Review with clinical data, validation]
- Harris WS, Del Gobbo L, Tintle NL. The Omega-3 Index and relative risk for coronary heart disease mortality: Estimation from 10 cohort studies. Atherosclerosis. 2017;262:51-54. DOI: 10.1016/j.atherosclerosis.2017.05.007 [Meta-analysis, k=10 cohorts]
- Harris WS, Tintle NL, Imamura F et al. Blood n-3 fatty acid levels and total and cause-specific mortality from 17 prospective studies. Nat Commun. 2021;12(1):2329. DOI: 10.1038/s41467-021-22370-2 [Meta-analysis, k=17 cohorts, n=42,466]
- Flock MR, Skulas-Ray AC, Harris WS et al. Determinants of erythrocyte omega-3 fatty acid content in response to fish oil supplementation: a dose-response randomized controlled trial. J Am Heart Assoc. 2013;2(6):e000513. DOI: 10.1161/JAHA.113.000513 [RCT, n=115, dose response]
- Pipingas A, Cockerell R, Grima N et al. Randomized controlled trial examining the effects of fish oil and multivitamin supplementation on the incorporation of n-3 and n-6 fatty acids into red blood cells. Nutrients. 2014;6(5):1956-1970. DOI: 10.3390/nu6051956 [RCT, n=160]
- Skulas-Ray AC, Flock MR, Richter CK et al. Red Blood Cell Docosapentaenoic Acid (DPA n-3) is Inversely Associated with Triglycerides and C-reactive Protein (CRP) in Healthy Adults and Dose-Dependently Increases Following n-3 Fatty Acid Supplementation. Nutrients. 2015;7(8):6390-6404. DOI: 10.3390/nu7085291 [RCT, n=115 and n=28]
- Schuchardt JP, Beinhorn P, Hu XF et al. Omega-3 world map: 2024 update. Prog Lipid Res. 2024;95:101286. DOI: 10.1016/j.plipres.2024.101286 [Review, 328 studies, n=342,864]
- Schuchardt JP, Cerrato M, Ceseri M et al. Red blood cell fatty acid patterns from 7 countries: Focus on the Omega-3 index. Prostaglandins Leukot Essent Fatty Acids. 2022;179:102418. DOI: 10.1016/j.plefa.2022.102418 [Cross sectional, n=167,347]
- von Schacky C. Omega-3 index in 2018/19. Proc Nutr Soc. 2020;79(4):381-387. DOI: 10.1017/S0029665120006989 [Review, methodology and standardisation]
- von Schacky C. Omega-3 index and cardiovascular health. Nutrients. 2014;6(2):799-814. DOI: 10.3390/nu6020799 [Review]
- von Schacky C. Omega-3 Fatty Acids in Pregnancy: The Case for a Target Omega-3 Index. Nutrients. 2020;12(4):898. DOI: 10.3390/nu12040898 [Review, pregnancy and upper limit]
- von Schacky C, Harris WS. Why docosapentaenoic acid is not included in the Omega-3 Index. Prostaglandins Leukot Essent Fatty Acids. 2018;135:18-21. DOI: 10.1016/j.plefa.2018.06.003 [Review, definition]
- Harris WS. The omega-3 index: clinical utility for therapeutic intervention. Curr Cardiol Rep. 2010;12(6):503-508. DOI: 10.1007/s11886-010-0141-6 [Review]
- Fielding BA. Omega-3 index as a prognosis tool in cardiovascular disease. Curr Opin Clin Nutr Metab Care. 2017;20(5):360-365. DOI: 10.1097/MCO.0000000000000404 [Review, critical appraisal]
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Important note: This text serves general information and replaces neither a medical examination nor individual advice. It contains no intake recommendation. The dosages mentioned are study protocols from the scientific literature. Please discuss any change to your supplementation with your doctor, especially if you have existing conditions, are pregnant or breastfeeding, or are taking medication.