Does Fish Oil Lower Blood Pressure?

According to research, fish oil may lower blood pressure. Along with lifestyle changes like eating a healthy diet and losing extra weight, there's some evidence that adding fish oil to your diet may help keep blood pressure in check and control high blood pressure (also known as hypertension).

Fish oil is high in omega-3 fatty acids, healthy fatty acids you need to get from dietary sources. As an antioxidant, it helps reduce oxidative stress and inflammation. You can increase your dietary intake of fish oil through natural sources (fish) or supplements.

This article explains the benefits of fish oil, including how fish oil lowers blood pressure and boosts heart health to reduce the risk of heart attack and stroke. It also discusses fish oil sources and recommended amounts, side effects, and interactions.

Benefits of Fish Oil on Heart Health

Fish oil is rich in omega-3 fatty acids, a form of polyunsaturated fat considered essential for good health. Fish oil benefits heart health by reducing risk factors for heart disease and improving cardiovascular health.

Lowers Blood Pressure

Omega-3 fatty acids have the ability to lower blood pressure in people with high blood pressure by a significant amount—12/7 millimeters of mercury (mmHg) or more. Omega-3 fatty acids are also effective in lowering blood pressure in people with high blood pressure and diabetes.

High blood pressure can cause damage if left untreated. Over time, it can lead to heart disease, heart attack, stroke, and other complications.

Both fish oil from fish and fish oil supplements have the ability to lower blood pressure.

Slows Plaque Development

Fatty substances, cholesterol, and other products can form plaque deposits in the arteries. When plaque builds up, it makes the artery walls thick and stiff, leading to atherosclerosis. High blood pressure, high cholesterol and triglyceride levels, and other factors increase the risk of atherosclerosis.

The omega-3 fatty acids in fish oil may be able to counter these negative effects by stabilizing and reversing vulnerable atherosclerotic plaques. Thus, they can reduce the risk of cardiovascular events, which include heart attack or stroke.

Reduces Risk of Arrhythmia

Omega-3 fatty acids seem to offer excellent protection against cardiac arrhythmias. Cardiac arrhythmia means an abnormal heart rhythm.

If you're consuming omega-3 fatty acids every day, your body will store excess in heart cells, helping to make those cells resistant to arrhythmias. Long-chain omega-3 fatty acids from marine sources like fish oil are what to look for.

Reduces Risk of Heart Attack and Stroke

Research shows that fish oil may be able to reduce the risk of heart attack and stroke. Fish oil may also be used as an additional therapy in people who don't have optimal treatment for heart disease and can even lower the risk of heart attack and stroke in this population.

Fish oil reduces heart attack and stroke by lowering blood pressure, reducing inflammation, acting as an antioxidant, lowering blood lipids (like triglycerides), and more. However, more research is still needed in this area.

Reduces Risk of Death in Heart Disease

Heart disease is the leading cause of death for people in the United States. It kills one person every 33 seconds. Coronary artery disease is the most common form of heart disease. Heart attacks are also common.

Having about two servings of fish a week may be able to reduce death from heart disease regardless of whether you have existing heart problems or not. Getting fish oil from natural sources is recommended over supplements.

Improves Endothelial Function

High blood pressure is closely associated with a dysfunction in the endothelium, the layer of cells lining your blood vessels, heart, and other organs. The endothelium is involved in a number of physiological processes affecting cardiovascular health, like the contraction and relaxation of blood vessels and blood clotting.

Endothelial dysfunction is linked to plaque build-up in your arteries (atherosclerosis), causing narrowing. This condition can lead to heart attacks and stroke.

The antioxidative properties of fish oil can protect the endothelial cells. This translates to better blood vessel health and is associated with lower blood pressure levels.

Increases Arterial Elasticity

The ability of your arteries to contract and expand (elasticity) is important for maintaining a constant blood pressure. This is especially true for the arteries close to the heart that feel the greatest effects from the heart's pumping action.

The stiffer your arteries are, the more likely you are to have high blood pressure. This can contribute to the risk of heart disease, especially in people with a family history of high cholesterol. The good news is that the omega-3 fatty acids in fish oil have been shown to improve the elasticity of the large arteries in those with a family history of high cholesterol.

Reduces Triglycerides

Triglycerides are a type of fat (lipid) found in the blood. High levels of triglycerides put you at increased risk of heart disease and stroke.

Dietary sources of fish oil, including supplements, can have a positive effect on high triglycerides. Supplements contain many types of omega-3 fatty acids. Some evidence suggests that 1 gram per day of long-chain omega-3 fatty acids (eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA) can help lower triglycerides, as can eating 8 ounces of a variety of seafood each week.

Prescription omega-3 fatty acid medication is available for people with triglyceride levels above 500 milligrams per deciliter.

Sources and Recommended Amounts for Fish Oil

You can increase your intake of fish oil by incorporating fish into your diet or taking fish oil supplements.

Fish Oil Supplements

If you're taking fish oil supplements, the recommended amount is no more than 5 grams of omega-3s a day.

Fish oil supplements are sourced from a variety of fish. Fish oil isn't the only type of omega-3 supplement available. You can also find omega-3s in:

• Fish liver oil supplements
• Krill oil
• Algal oils
• Flaxseed oil

Fish oil supplements can contain impurities and have varying doses. If you are using a fish oil supplement, do your research to make sure the product you are buying comes from a good source.

Dietary Sources of Fish Oil

You can get enough fish oil from your diet. Natural sources of fish oil include:

• Salmon
• Anchovies
• Sardines
• Pacific oysters
• Trout
• Tilapia
• Shrimp
• Catfish
• Crab
• Flounder
• Tuna
• Sardines
• Herring

Dietary sources of fish oil are recommended over supplements. For a heart-healthy diet rich in omega-3s, aim for about two servings of fish each week.

Side Effects of Fish Oil

Fish oil supplements generally don't cause side effects. When they do occur, side effects tend to be mild and go away on their own. Side effects of fish oil supplements include:

• Bad breath
• Heartburn
• Nausea
• Gastrointestinal upset
• Bleeding tendency
• Heavy metal poisoning

Generally, the risk of bleeding is mild, even if you are taking antiplatelet medications (like aspirin) to help prevent blood clotting.

Heavy metals like mercury can show up in seafood. However, fish oil supplements usually contain very small amounts that are unlikely to be harmful. Plus, the purification process for fish oil supplements helps to remove heavy metals present in fish.

Fish oil supplements should be used cautiously and only with supervision by a qualified healthcare professional.

The safety of supplements in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications has not been established.

Risk of Atrial Fibrillation

Although fish oil can help protect against arrhythmia, there appears to be a Goldilocks zone when it comes to atrial fibrillation. Omega-3 fatty acid intake that is too high or too low may increase the risk of atrial fibrillation, but the right amount can lower it.

What's right for you will depend on several factors, including the dose, type and formulation of the omega-3 fatty acids (whether from food sources or supplements), as well as your age, sex, clinical risk factors, and atrial function.

If you're taking supplements, sticking to a dose of less than 2 grams a day may help reduce the risk of atrial fibrillation.

Talk to a healthcare provider or registered dietician before adding fish oil to your diet.

Interactions of Fish Oil With Other Substances

Fish oil can interact with the effects of warfarin and similar anticoagulant medications.

People taking warfarin and fish oil may have longer clotting times. Generally, 3 to 6 g of fish oil a day is considered safe. Your healthcare provider may want to monitor your blood for indicators of clotting.

Summary

In addition to adopting healthy lifestyle practices, adding fish oil to your diet may help you manage your blood pressure. Fish oil has been shown to lower blood pressure and improve other markers of heart health. Including fish oil in your diet can help you reduce the risk of heart disease and stroke.

Fish oil is high in omega-3 fatty acids. The best way to increase your dietary intake is to go straight to the source by eating fish. Dietary supplements are also available. However, high doses of fish oil may cause side effects, and fish oil can interact with anticoagulants like warfarin.

If you are considering taking fish oil supplements, speak with your healthcare provider or registered dietician first to make sure it's appropriate and safe for you.