Can Omega-3 Levels Predict Your Risk of Dying?

What if there were a simple way to identify your risk of dying? Perhaps that’s not a cheerful thought, but having such information can help you be proactive and take preventive measures. According to research funded by the National Institutes of Health, knowing your level of omega-3 predicts your risk of dying from all causes, and not just cardiovascular disease.

Why should we measure omega-3 fatty acids?

The authors of the new study, which appears in the Journal of Clinical Lipidology, reported on the value of measuring blood levels of omega-3 fatty acids, which are dominated by eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The study involved 2,500 individuals, who were the offspring cohort of the Framingham Heart Study. Their average age was 66 years, and they were tracked until about age 73. All subjects were free of cardiovascular disease at the start of the study.

Measurements of EPA and DHA reflected the amount of these omega-3s found in the membranes of red blood cells. The authors observed that having a higher omega-3 index was associated with significant health benefits, including a lower risk for total strokes, total coronary heart disease episodes, and total cardiovascular events. They also noted a strong relationship between the omega-3 index and dying from all other causes. More specifically:

  • Individuals who had the highest levels of omega-3s reduced their risk of dying from any case by 34 percent.
  • Those with the highest omega-3 levels also had a 3 percent lower risk of having a cardiovascular event (e.g., stroke, heart attack)

Comparing omega-3 and cholesterol values

For some time, high cholesterol has been considered to be a significant risk factor for heart disease, even though this has been shown to be incorrect. In this new study, the researchers decided to compare omega-3 and cholesterol to identify which factor is a better predictor of mortality. When the authors looked at five outcomes, they found that serum cholesterol was not significantly associated with higher mortality but omega-3 was in four of the five outcomes evaluated.

How omega-3 levels are measured

Omega-3 index can be measured using a simple blood test that identifies the amounts of EPA and DHA in red blood cell membranes. The figure your doctor gives you reflects the percentage of your total red blood cell fatty acids. What do the numbers mean?

  • An omega-3 index of greater than 8 percent (which is typical in Japan) is associated with the lowest risk of dying from heart disease
  • An index lower than 4 percent, which is common among Europeans and Americans, is the highest risk of heart disease-related death

People who engage in vigorous exercise, such as many athletes, burn their omega-3 supplies very quickly because DHA is used as a fuel instead of being allocated to the cell membranes. Therefore, active people who eat fish may still need to consider taking an omega-3 supplement.

What is the role of omega-6 fatty acids?

Some research has suggested that omega-6 fatty acids (fond in vegetable oils, nuts, and seeds) may play an equal role in reducing the risk of dying prematurely. One meta-analysis in particular, which was conducted at the University of Eastern Finland, followed about 2,500 middle-aged men and measured their blood levels of fatty acids. The men were part of the Kuopio Ischaemic Heart Disease Risk Factor study.

The participants were categorized based on the level of omega-6 fatty acid linoleic acid found in their bloodstream. They discovered that:

  • Men who had the highest blood levels of linoleic acid had a 43 percent lower risk of dying than men with the lowest levels of the fatty acid.
  • Those with higher levels of linoleic acid were less likely to die from cardiovascular disease or other cases
  • Overall, the higher a man’s level of linoleic acid, the smaller his risk of premature death
  • Earlier research indicates that having a higher blood level of linoleic acid is associated with a reduced risk of cardiovascular disease and type 2 diabetes

Omega-3 and omega-6 fatty acids

The standard American diet (SAD) typically falls short on omega-3s but not on omega-6s. This means that the ideal ratio of omega-3s to omega-6s, which is often said to be 1-to-1, is actually more like 1-to-20 or even greater, depending on how much fast food and processed food you eat. These foods generally contain some type of vegetable oils, which are rich in omega-6 fatty acids.

Omega-6 fatty acids pose a number of health issues. Among the most important is chronic inflammation, a factor that plays a significant role in heart disease, dementia, arthritis, inflammatory bowel disease, some cancers, periodontitis, and obesity, among others.

Generally, if you eat a diet that is high in omega-3s and low in omega-6s, you can reduce inflammation. So where can you get omega-3s?

Where to find omega-3 fatty acids

The best way to include omega-3 fatty acids in your diet is to include items such as cold water fatty fish. You want to focus on smaller cold-water fish, such as anchovies and sardines, because they are less likely to be significantly contaminated with mercury and other toxins such as cadmium, lead, radioactive poisons, and arsenic. Wild Alaskan salmon is another wise choice, but stay away from any farmed salmon or other farmed fish as well as larger wild fish, including tuna, marlin, and swordfish.

Other sources of omega-3 fatty acids include:

Fish oil: Use of a reputable fish oil supplement is a convenient way to boost your intake of omega-3 fatty acids. Because fish oil can oxidize easily, be sure to store it according to the package directions. If you want to take fish oil for general cardiovascular health, one 1,000 mg softgel (offering about 300 mg EPA and 200 mg DHA) is usually felt to be sufficient. If you are managing an existing heart problem or other specific health concern, a higher dose is usually suggested.

Krill oil. Minute sea creatures called krill are another source of omega-3s. Krill oil contains more EPA than does fish oil and it also tends to be more easily absorbed. Unlike fish oil, krill oil can cross the blood-brain barrier and provide positive effects on the brain.

Astaxanthin. This powerful antioxidant is a pigment that is found in salmon, krill, and several other foods. In fact, krill oil contains astaxanthin, which is one reason it is considered by some to be superior to fish oil for those who want an omega-3 supplement. In addition, taking astaxanthin as a stand-alone supplement, when used with fish oil or krill oil, can reduce the risk of the oil oxidizing while also boosting its ability to enhance the immune system. Here is the best astaxanthin supplement which we like.


Farvid MS et al. Dietary linoleic acid and risk of coronary heart disease: a systematic review and meta-analysis of prospective cohort studies. Circulation 2014 Oct 28; 130(18): 1568-78

Harris WS et al. Erythrocyte long-chain omega-3 fatty acid levels are inversely associated with mortality and with incident cardiovascular disease: The Framingham Heart Study. Journal of Clinical Lipidology 2018

Mercola J. Omega-3 level is the best predictor of mortality. 2018 April 4

Virtanen JK et al. Serum n-6 polyunsaturated fatty acids and risk of death: the Kuopio ischaemic heart disease risk factor study. The American Journal of Clinical Nutrition 2018 Mar 1; 107(3): 427-35