High blood pressure: omega-3 EPA and DHA lower it

High blood pressure is a widespread condition in Western countries and poses a threat to heart health. According to recent research, omega-3 consumption appears to promote a decrease in blood pressure. Specifically, in people with isolated systolic hypertension, a daily dose of 0.7 grams of EPA and DHA, which can be achieved by eating 2-3 servings of fish or with dietary supplements, is sufficient to reduce blood pressure by about 5 mmHg.

These are the findings of a British study conducted by a team of researchers from the Universities of East Anglia, Reading, Southampton, Glasgow and Newcastle (UK) and published in the Journal of Nutrition.

High blood pressure: a cardiovascular risk factor

Blood pressure represents the force exerted by blood on the walls of the arteries through which it flows and is measured in millimeters of mercury (mmHg). When the heart contracts and blood passes into the arteries, the highest blood pressure, called systolic or "maximum," is recorded; between beats, on the other hand, the heart fills with blood and the lowest blood pressure, called diastolic or "minimum," is recorded in the arteries. 

When systolic blood pressure in adults exceeds 140 mmHg and diastolic blood pressure exceeds 90 mmHg, it is referred to as hypertension or more commonly "high blood pressure." This is an important risk factor for cardiovascular diseases such as stroke, myocardial infarction and aneurysms. Isolated systolic hypertension is the typical form of hypertension in old age and is defined by systolic values greater than 140 mmHg, while diastolic pressure is less than 90 mmHg. Hypertension is a widespread condition in Western countries; an estimated 15 million Italians suffer from it. Hypertension is promoted by several conditions, genetic but also related to age and lifestyle:

• Advanced age
• Overweight
• Smoking and alcohol consumption
• Salt abuse
• Diet high in fat and low in fruits and vegetables
• Hypercholesterolemia or Hypertriglyceridemia
• Genetic predisposition
• Stress and anxiety

700 milligrams of omega-3 is associated with lower blood pressure

The new British study, during which data obtained from more than 300 healthy citizens were analyzed, found that consuming 0.7 grams of EPA and DHA daily for eight weeks was associated with a 5.20 mmHg reduction in systolic blood pressure, while a daily dose of 1.8 grams of EPA and DHA with a 5.3 mmHg decrease. 

A result that, according to the authors of the research themselves, is also important because it highlights that consuming these amounts of omega-3s is easily achieved through the consumption of 2-3 servings of oily fish per week, or about 2 capsules of fish oil supplements. In fact, the two doses of omega-3s tested (0.7 and 1.8 grams of EPA and DHA) are significantly lower than those used in most similar studies done previously. 

In addition, the resulting decrease in blood pressure is associated with an approximately 20 percent reduction in cardiovascular risk, in middle-aged people. Commenting on this work, Harry Rice of GOED, an association that promotes the consumption of adequate levels of Omega-3, added that although the research is related to systolic hypertension, it confirms an earlier study. Last year, in fact, a meta-analysis found that EPA and DHA reduced systolic blood pressure by an average of 4.5 mmHg and diastolic by 3.0 mmHg . These data prompted the GOED to request the FDA (Food and Drug Administration), the U.S. agency that regulates food and pharmaceuticals, to issue health claims recommending omega-3s for hypertension.

Some details of the study

The British researchers arrived at the observations outlined through a retrospective analysis of a study that had involved 312 healthy people. Each of these randomly received either a 0.7-gram dose of EPA and DHA or 1.8 g of the same omega-3s, or an oil containing no omega-3s at all, for 8 wks. Fasting blood pressure and vascular function were then measured by means of specific assays. The results showed that while no benefit was observed for the group of subjects in total, a significant effect was reported on the subjects with hypertension, particularly in the 31 persons with isolated systolic hypertension.

 According to statistics, in countries such as the United Kingdom and the United States, more than 30 percent of adults suffer from high blood pressure. In those without major symptoms, the threshold for drug treatment is a systolic blood pressure greater than or equal to 160 mm Hg and diastolic blood pressure greater than or equal to 100 mg Hg. As a result, in the United Kingdom, about half of men and one-third of women with hypertension receive no drug treatment, despite evidence of an association between hypertension and cardiovascular risk.

Omega-3 to keep blood pressure under control

According to the researchers, therefore, research suggests that increased consumption of EPA and DHA could be an effective strategy for blood pressure control in people not taking high blood pressure medication, this, at the population level, may be associated with a lower risk of cardiovascular disease. 

However, more studies with participants recruited on the basis of blood pressure status will be needed to draw firm conclusions. To stay up-to-date on the latest news from Omega-3 scientific research, sign up for our newsletter. 

Source: A.M. Minihane, et al. "Consumption of fish oil providing amounts of Eicosapentaenoic Acid and Docosahexaenoic acid that can be obtained from the diet reduces blood pressure in adults with systolic hypertension: a retrospective analysis"Journal of Nutrition, 2016 Mar;146(3):516-23.