Fish oil is one of the most popular dietary supplements in the world.
Many people take it to protect their hearts, lower cholesterol, or reduce blood pressure. Its health benefits come from omega-3 fatty acids, healthy fats that the body cannot make on its own.
The two main omega-3 fatty acids in fish oil are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).
They are naturally found in oily fish such as salmon, sardines, mackerel, and herring. These healthy fats help reduce inflammation, which plays a role in many heart and blood vessel diseases.
When talking about cholesterol, it is important to understand that there are different types. LDL cholesterol is often called ‘bad’ cholesterol because high levels can build up inside arteries and increase the risk of heart attacks and strokes. HDL cholesterol is known as ‘good’ cholesterol because it helps carry extra cholesterol away from the bloodstream.
Research shows that fish oil does not usually lower LDL cholesterol by a large amount. However, studies have found that it can increase HDL cholesterol in some people and is especially effective at lowering triglycerides, another type of fat in the blood.
High triglyceride levels are linked to a greater risk of heart disease, and fish oil has been shown to reduce them by about 15% to 30% in many studies.
Fish oil may also help people with high blood pressure. Hypertension forces the heart to work harder and can damage blood vessels over time. This increases the risk of heart attacks, strokes, heart failure, and kidney disease.
Scientists believe omega-3 fatty acids help blood vessels relax and widen, making it easier for blood to flow through the body. As a result, fish oil can produce a small but meaningful reduction in blood pressure, especially in people who already have hypertension.
Several large research reviews have supported these benefits. Meta-analyses of randomized clinical trials have found that omega-3 supplements are linked to a lower risk of heart attacks and other major cardiovascular events. Other studies have also reported improvements in blood pressure among people taking fish oil regularly.
Although these findings are encouraging, fish oil should not be viewed as a replacement for healthy living or prescribed medicines. The greatest benefits are seen when it is combined with a balanced diet, regular physical activity, maintaining a healthy weight, and avoiding smoking.
Not all fish oil supplements are made to the same standard. Choosing products that have been independently tested for quality and purity can help reduce the risk of contaminants such as mercury and ensure the supplement contains the amount of omega-3 listed on the label.
Overall, research suggests that fish oil can support heart health by lowering triglycerides and providing a modest reduction in blood pressure, even though it has little effect on LDL cholesterol.
Anyone thinking about taking fish oil, especially people with heart disease or those using blood-thinning medicines, should speak with their healthcare provider first to make sure it is safe and appropriate.
If you care about blood pressure, please read studies about how diets could help lower high blood pressure, and 3 grams of omega-3s a day keep high blood pressure at bay.
For more health information, please see recent studies about how tea and coffee influence your risk of high blood pressure, and results showing this olive oil could reduce blood pressure in healthy people.
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