Omega-3 index reveals heart health status

Heart: omega-3 index indicates its health status

Regular consumption of omega-3-rich fatty fish (mackerel, salmon, herring etc.) is associated with a reduced risk of cardiovascular disease, as shown by numerous studies over the past 30 years. Levels of the two main omega-3s, EPA and DHA, in the blood reflect the intake of unsaturated fatty acids ingested with food and possibly that of fish oil and algal oil supplements. Blood DHA and EPA concentrations can be measured by the Omega-3 Index, or Omega-3 Index, a new tool for assessing cardiac risk.

Therefore, it is no longer only cholesterol and triglyceride levels that indicate cardiovascular risk:today heart health is also defined by this new factor.

The omega-3 index: a measure of omega-3 in the blood

The Omega-3 Index indicates the amount of EPA and DHA out of the total fatty acids in red blood cell membranes.The fatty acid composition of red blood cells is therefore an indicator of nutritional status and risk for the heart.The omega-3 index represents an independent element with respect to estimated dietary intake of omega-3. Indeed, there are differences related to metabolism or genetic variability in each individual, just as there can be error in estimating dietary omega-3 intake, for example, due to consumption of fish varieties containing different amounts of EPA and DHA.

The Omega-3 index: the story

The Omega-3 Index was developed, in 2004, as a signal for the risk of sudden cardiac death by William Harris, a professor at the University of South Dakota (USA), and Professor Clemens von Schacky, a cardiologist at the University Of Munich (Germany). Sudden cardiac death is a death from cardiac arrest that occurs unexpectedly even in individuals who have never exhibited cardiac dysfunction. Harris and von Schacky found that the risk of this fatal phenomenon was related to the amount of EPA and DHA in red blood cells. Specifically, by reviewing some major epidemiological studies, they found that:

• L’indice Omega-3 < del 4% indica una forte probabilità per un individuo di essere colpito da morte cardiaca improvvisa
• Omega-3 Index between 4 and 8% is synonymous with moderate risk
• Omega-3 Index > 8% indicates a low-risk situation

The likelihood of fatal cardiac events is reduced by up to 90 percent in individuals in the category with the highest value, compared with those with the lowest index.How can an optimal Omega-3 Index be achieved? An Omega-3 Index of 8 percent is achievable through daily consumption of about 500 milligrams of EPA and DHA obtainable from two or more servings of fatty fish per week, or through supplements. The Omega-3 Index, like other cardiovascular risk factors, can thus be modified by a healthier lifestyle.

Some studies underlying the findings of Harris and von Schacky

The inverse relationship between omega-3 fatty acids and the risk of sudden cardiac death has been investigated by several researches in recent decades. In particular, Harris and von Schachy reviewed numerous scientific publications in which low omega-3 levels were found to be associated with the risk of sudden cardiac death. Among the most important scientific research in favor of the two scholars' interpretations should certainly be mentioned the "Health Study Physicians," a study of physicians in which it was found that subjects with an Omega-3 Index of 6.53 percent had a 90 percent lower risk of sudden cardiac death, compared with those with an index of 3.75 percent. In line with this, the "Cardiovascular Health Study," showed that higher levels of EPA and DHA in plasma membranes were strongly associated with a lower risk of fatal ischemic heart disease.

The Italian "GISSI" study was conducted in 172 cardiology centers on more than 11,000 patients who survived myocardial infarction. The subjects were divided so that they received 4 different treatments: one group omega-3, another vitamin E, the third omega-3 and vitamin E, and the control group with a placebo. At the end of the study period, omega-3 treatment was shown to be the only one effective in reducing heart attack mortality by 10-15%, and sudden cardiac death by 40%. Other studies taken into account include those conducted in parts of Europe with populations characterized by relatively low blood omega-3 concentrations, such as Belfast, where the incidence of sudden cardiac death is 122 per 100,000 people per year.

In contrast, the Japanese, a population with a high dietary intake of omega-3, average incidence of sudden cardiac death is only 7.8 per 100,000 people per year. 

How is the Omega-3 Index calculated?

The Omega-3 index is the sum of the omega-3 fatty acids EPA DHA in the blood cell membranes and is expressed as the percentage of EPA and DHA out of the total fatty acids in the membrane. The choice to use blood cell membrane concentrations is due to the fact that polyunsaturated fatty acids in these structures are more biologically stable (they hardly vary from week to week). Red blood cell membranes are then technically easier to analyze and reflect the long-term intake of EPA and DHA, indicating true omega-3 status, similar to the measurement of glycosylated hemoglobin in the diagnosis of diabetes. The effects of EPA and DHA appear to stem mainly from their ability to change the flexibility of cell membranes by making them more fluid. The alteration of the physical properties brought to the membrane level by EPA and DHA is reflected in the functionality of the proteins embedded in it, initiating a series of reactions within the cell that culminate in the regulation of numerous genes. These mechanisms lead to certain benefits such as the reduction of inflammation molecules, the decrease in blood triglycerides, and the stabilization of plaques responsible for atherosclerosis.

The Omega-3 Index Test

The Omega-3 Index in blood can be a new diagnostic tool and be used in the routine clinical evaluation of patients. Its determination requires the Omega-3 Index, a blood test that can be performed in laboratories that follow a strict quality management system. Measurement of the Omega-3 Index is highly reproducible, and values can be obtained within several hours. Quantifying the fatty acids in an individual is useful for physicians and patients to estimate the risk of heart disease, and to achieve the adequate levels of omega-3 needed to reduce the risk of heart attack and sudden mortality.

The HS-Omega-3 Index®

The HS-Omega-3 Index® is a kit provided by U.G.A. Nutraceuticals and allows anyone who wants it to easily determine their Omega-3 Index, using the same technique in the Harris and von Schacky clinical studies. The HS-Omega-3 Index® includes everything you need to be able to determine your Omega-3 Index at home. Just collect 3 drops of blood with the finger-prick lancet on a special filter paper to be sent to the specific laboratory. The result will be communicated after a few days via e-mail to the client directly from the laboratory and in strict confidence.

Other evidence of the relationship between the Omega-3 Index and cardiovascular health

Omega-3 fatty acids have antiarrhythmic effects; in fact, they can decrease heart rate as shown in a study of 402 patients who received 2.6 grams per day of EPA and DHA. After 12 months of treatment, the Omega-3 Index had increased from 3.4 percent to 7.6 percent in the intervention group, while it had not changed in the placebo group included in the research. Subjects who had taken omega-3 had shown a 28 percent reduction in the risk of ventricular tachycardia, ventricular fibrillation or death. 

Research published in the prestigious journal Lancet, in 2003 showed that in patients diagnosed with coronary artery disease, administration of 1.6 grams per day of EPA and DHA increased the Omega-3 Index from 3.4% to 8.3% and reduced the progression of coronary lesions. These results suggest that increasing the Omega-3 Index to levels above 8% can mitigate the progression of coronary atherosclerosis and reduce the number of unstable plaques by lowering the risk of heart attack.

The Optimal Omega-3 Index: also a benefit for diabetics?

Relationships between omega-3 index value and health status also appear to involve other diseases besides those closely related to the heart. A study published in Diabetes Care examined the relationship between high levels of nonesterified fatty acids, that is, circulating free lipids, and the risk of type 2 diabetes and the possible action of omega-3 on this relationship. Values obtained from about 5700 subjects, showed a higher incidence of diabetes in those who had the highest concentrations of nonesterified fatty acids and a significant interaction of omega-3s. Individuals with an Omega-3 Index of 3.9 percent showed, in fact, a higher risk of diabetes than those with the Omega-3 Index of 7.5 percent. Thus, the latter group was the one showing the greatest benefits, in agreement with studies suggesting that an Omega-3 Index of 8 percent is associated with lower cardiovascular risk.

Postpartum depression and low Omega-3 Index: relationship found

A high Omega-3 Index would also be a benefit to mental health, according to research published in 2013 in the journal Plos One. According to researchers, a low Omega-3 Index could be a risk factor for the onset of postpartum depression, a condition that commonly occurs in women soon after the birth of a child. In fact, the study related the Omega-3 index measured during the 28th week of gestation and the possible diagnosis of postnatal depression 3 months after delivery. The results showed a link between the disease and EPA and DHA deficiency in red blood cells and the need to consume the correct amount of fish during gestation. These data agree with those of other research that has suggested the protective role of omega-3s with respect to different forms of depression or behavioral disorders in adults, the elderly and the young.

In adolescents, omega-3s improve attention

A recent Dutch study, published in the journalNutrients, has shown that a high Omega-3 Index is positively associated with certain cognitive characteristics, as measured by special tests in adolescents. Specifically, the researchers verified a significant increase in the ability to process information corresponding to a 1 percent increase in Omega-3 Index. In addition, young people with the highest values of this parameter showed more alertness and fewer errors when taking the tests themselves.

How does the Omega-3 Index vary in populations?

Although recommendations for a healthy and proper diet call for fish consumption at least two to three times a week, omega-3 intake in Western countries is very low. One of the latest surveys, published in December in Nutrients, and conducted using data on the U.S. population regarding blood omega-3 concentrations, found that about 96 percent of adults have an omega-3 index of less than 4 percent. A value that is not surprising since on average the daily dietary intake of EPA and DHA is 8 and 50 milligrams per day, respectively. 

In the same months of 2015, a study reported Omega-3 Index and coronary heart disease risk on a representative sample of Canadian adults. Overall, the results show that less than 3 percent of them have an Omega-3 Index associated with a low risk of cardiovascular disease. But Americans and Canadians are not the only ones with a poor Omega-3 Index; a study published in recent months investigated the status and distribution of omega-3 levels in the Saudi Arabian population finding that the Omega-3 Index was, on average, 3.8 and that 46% of females and 39% of males had an Omega-3 Index even lower than 3.5%.

In summary, knowing one's Omega-3 Index is important because:

• It can estimate the risk of sudden cardiac death both in the general population and in patients with coronary artery dysfunction.
• It is easily measured.
• It is more discriminating than most other known risk factors.
• It can identify individuals who need to increase omega-3 consumption and then evaluate the progress achieved.

SourcesMurphy RA, Yu EA, Ciappio ED, Mehta S, McBurney MI. Suboptimal plasma long chain n-3 concentrations are common among adults in the United States, NHANES 2003-2004. 2015 Nutrients Harris WS. The omega-3 index as a risk factor for coronary heart disease. 2008 Am J Clin Nutr 87(6): 19975-20025 Langlois K, Ratnayake WM. Omega-3 index of Canadian adults. 2015 Health Rep 26(11) 82-003-x Bassam T, Superko HR, Caulfield M. Cardiovascular disease risk attributed to blood fish oil (omega-3 fatty acid) levels differ significantly in Saudi men and women. 2015 J Saudi Heart Asso Weir NL, Tsai MY. n-3 fatty acids attenuate the risk of diabetes associated with elevated serum non-esterified fatty acids: the Multi-Ethnic Study of Atherosclerosis. 2015 Diab Care.