What is High Blood Pressure?
High blood pressure is diagnosed when a person has a blood pressure reading of greater than 140/90 mm Hg on 2 different occasions. Some causes of high blood pressure include:
Stress and fear
Being overweight
High salt intake
Excessive alcohol consumption
Lack of exercise
Genetics
High blood pressure can lead to other health problems such as:
Peripheral Arterial Disease (poor circulation in the legs)
Heart Attack
Stroke
Kidney damage
There are many lifestyle, medicinal, and supplement approaches to reduce blood pressure. One of which includes increasing omega-3 fatty acid intake.
Omega-3 Fatty Acid Background:
Omega-3 fatty acids are polyunsaturated fats found in fatty fish such as salmon, mackerel, tuna, and sardines. They are also in walnuts, flaxseeds, and canola oils. Foods can also be fortified with omega-3s, such as milk, egg, yogurt, juices, and more. There are also omega-3 fatty acid-containing supplements.
The three main types of omega-3s which are:
Alpha-lipoic acid (ALA)
Eicosapentaenoic acid (EPA)
Docosahexaenoic acid (DHA)
The daily recommended amount of omega-3 fatty acids depends on age and gender. Below is the recommended intake of omega-3 fatty acids, according to the National Institutes of Health (NIH):
Birth to 6 months*:
Male: 0.5 g
Female: 0.5 g
7-12 months*:
Male: 0,5 g
Female: 0.5 g
1-3 years**:
Male: 0.7 g
Female: 0.7 g
4-8 years **:
Male: 0.9 g
Female: 0.9 g
9-13 years**:
Male: 1.2 g
Female: 1.0 g
14-18 years**:
Male: 1.6 g
Female: 1.1 g
Pregnancy: 1.4 g
Lactation: 1.3 g
19-50 years**:
Male: 1.6 g
Female: 1.1 g
Pregnancy: 1.4 g
Lactation: 1.3 g
51+ years**:
Male: 1.6 g
Female: 1.1 g
* As total omega-3's
** As ALA
How Do Omega-3 Fatty Acids Affect Blood Pressure?
Omega-3 fatty acids have been shown to affect blood pressure. Morris et al. (1993) explain that omega-3 fatty acids can lower blood pressure by producing prostaglandins, which are fats that act like hormones and are responsible for controlling sodium and water excretion. They also cause vasodilation (opening of the blood vessels) and stop vasoconstriction (narrowing of the blood vessels) (Morris et al., 1993). Omega-3s can control renin release (blood pressure-controlling hormone) and lower the response of hormones that control blood vessels (Morris et al., 1993).
Although there may be conflicting results about whether omega-3 fatty acids can lower blood pressure, Morris et al. (1993) stated that the reasons previous studies found inconclusive evidence of omega-3 fatty acids on blood pressure is due to small sample sizes, doses of omega-3 fatty acids, study design, and participant health status. The authors examined 31 controlled trials that showed omega-3 fatty acids can have positive impacts on blood pressure (Morris et al., 1993) and reported a blood pressure decrease of 3.0 mm Hg and 1.5 mm Hg for systolic blood pressure and diastolic blood pressure, respectively, when participants consumed an average amount of 4.8 grams of omega-3 fatty acids daily for those with high blood pressure, while noticing little to no effect on blood pressure in participants with normal blood pressure (Morris et al., 1993). Zhang et al. (2022) performed a more recent analysis of different studies, which showed that 2-3 grams of omega-3 fatty acids lowered blood pressure. A more recent double-blinded, randomized controlled trial by Stanton et al. (2020) showed appropriate reductions in diastolic blood pressure and heart rate in participants who ate omega-3-enriched foods. They observed 143 participants after a 3- and 6-month follow-up and randomly placed participants in groups that ate 3 portions of omega-3-enriched chicken meat each week, 3 portions of omega-3-enriched eggs each week, or were part of the control for each treatment group (Stanton et al., 2020).
Omega-3 should be considered in treating high blood pressure because of its ability to lower pressure due to the hormonal effects on blood pressure control. Though the various studies showed significant improvements in blood pressure at different amounts of omega-3 consumption, it is important to note the upper limit of omega-3s, which Krupa et al. (2024) states is 3 grams, where no more than 2 grams come from fish oil supplements.
References
Krupa, K. N., Fritz, K., Parmar, M. (2024). Omega-3 Fatty Acids. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK564314/
Morris, M.C., Sacks, F., Rosner, B. (1993). Does Fish Oil Lower Blood Pressure? A Meta-Analysis of Controlled Trials. Circulation. 88(2) 523-532. https://www.ahajournals.org/doi/10.1161/01.cir.88.2.523?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
Office of Dietary Supplements. Omega-3 Fatty Acids: Fact Sheet for Health Professionals. National Institutes of Health. https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/
Stanton, A.V., James, K., Brennan, M.M., O’Donovan, F., Buskandar, F., Shortall, K., El-Sayed, T., Kennedy, J., Hayes, H., Fahey, A.G., Pender, N., Thom, S. A. M., Moran, N., Williams, D.J., Dolan, E. (2020). Omega-3 index and blood pressure responses to eating foods naturally enriched with omega-3 polyunsaturated fatty acids: a randomized controlled trial. Scientific Reports. 10(15444). 1-9. https://www.nature.com/articles/s41598-020-71801-5#:~:text=Numbers%20of%20subjects%20with%20a,%E2%88%92%205.8%2C%20%E2%88%92%200.3%5D).
Zhang, X., Ritonja, J.A., Zhou, N., Chen, B.E., Li, X. (2022). Omega-3 Polyunsaturated Fatty Acids Intake and Blood Pressure: A Dose-Response Meta-Analysis of Randomized Controlled Trials. J Am Heart Assoc. 11(11). 1-11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9238708/
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