Omega 3s to combat hypertension
Omega 3 fatty acids can offer moderate reductions in blood pressure, providing a cheap and simple means to combat hypertension in the general population.
Constant elevated blood pressure (hypertension) is a very common problem worldwide. Approximately 31% of Americans are hypertensive, while 30% are on the boundaries of developing hypertension.
Is hypertension such a big issue for health?
Yes, the constant strain exerted on blood vessels predisposes individuals to develop serious conditions such as heart disease, stroke and chronic kidney disease.
Hypertension is commonly treated with blood pressure lowering medication, but this costs a lot of money and there are always unwanted side effects.
The goal is to find safe and cheap interventions that are effective in reducing blood pressure to treat and to delay the occurrence of hypertension.
So why omega 3s?
The omega 3 fatty acids EPA and DHA are known to improve the lining (endothelium) of blood vessels and allow the blood to flow more smoothly, thereby helping to reduce blood pressure.
Many studies have shown reductions in blood pressure with the use of EPA and DHA, but a lot of these findings are not applicable to the rest of us.
You see, many trials have assessed the efficacy of omega 3s on patients who already have cardiovascular disease, and in those who already take blood pressure medication.
Hence, here I focus on a meta-analysis that assessed the effects of omega 3 on blood pressure in the general population in individuals not taking antihypertensive drugs.
A meta-analysis is a study that looks at multiple studies in one go, analysing the data over many years and summing up all the evidence in one scientific paper. Meta-analyses provide the highest level of scientific evidence, allowing medical professionals to make informed decisions.
This meta-analysis included the data obtained from 70 randomised controlled trials and analysed the effects of EPA and DHA ingestion on systolic and diastolic blood pressure.
Ok, let’s dive straight to the study findings now!
The researchers found that EPA and DHA reduced both systolic and diastolic blood pressure in both hypertensive and normotensive (without hypertension) patients.
Across all 70 studies in both normotensive and hypertensive patients, EPA and DHA reduced systolic blood pressure by -1.5 mmHg, and diastolic blood pressure by -1.0 mmHg.
In normotensive subjects, systolic blood pressure significantly decreased by -1.3 mmHg. Because blood pressure tends to increase by around 0.6 mmHg per year in adults, this means that high intakes of EPA and DHA could potentially delay systolic hypertension by over 2 years.
Meanwhile, the effects of EPA and DHA in reducing blood pressure in hypertensive subjects were more pronounced. Systolic blood pressure was reduced by -4.5 mmHg, and diastolic blood pressure by -3.1 mmHg.
Such reductions in blood pressure among hypertensive patients could prevent the need to take blood pressure lowering medications or maintain hypertensive patients at a lower stage of progressive hypertension.
However, please note that the mean daily dose of EPA + DHA that was given patients across all 70 studies was 3.8 g/day, which is quite a LARGE amount!
Yet, doses of EPA + DHA just under 1 g/day, lead to significant reductions in systolic blood pressure of -2.4 mmHg.
In most studies analysed in this meta-analysis, EPA and DHA was given to patients as fish oil. As for the control groups, patients were given other types of oils to consume, such as olive, corn, sunflower oil.
Overall, by lowering blood pressure, EPA and DHA can reduce the risk of cardiovascular events, improving the quality of life in individuals and saving costs to the healthcare system.
Miller, P.E., Van Elswyk, M. & Alexander, D.D. (2014). Long-chain omega-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid and blood pressure: a meta-analysis of randomized controlled trials. American journal of hypertension, 27(7), 885–896.
This post was written by Juan Girones, Medical Writer at Havas Life Medicom.
You can read more of his work on his blog Nutrisphere on Medium: Precise and up-to-date nutrition and medical information.