Fish oil contains omega-3 fatty acids, types of fat important for certain bodily processes. Omega-3 fatty acids can help lower a person’s blood pressure. However, their effect on cholesterol is controversial.
The three main types of omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Fish oil contains EPA and DHA. Although the body can make very small amounts of DHA and EPA from ALA, it is important to get DHA and EPA through diet and/or supplementation. . Read on to learn more about the effects of fish oil on cholesterol and blood pressure, how much to consume, and other health benefits.
What is the problem with high cholesterol?
Cholesterol is a fatty substance found in a person’s blood. The liver makes all the cholesterol the body needs to build new cells and create certain hormones. However, people ingest additional cholesterol from Safe Source by eating foods of animal origin. Cholesterol moves through the body in the form of lipoproteins. There are many types of lipoproteins, but the two main ones are:
Low density lipoproteins (LDL): LDL is the “bad” cholesterol. If a person has too much LDL in their blood, it can build up on the walls of their arteries. This buildup can lead to problems, such as a heart attack or stroke.
High Density Lipoproteins (HDL): HDL is the “good” cholesterol. It helps move LDL cholesterol from the arteries to the liver, which removes it from the body.
Triglycerides are another type of fat in the blood that the body uses for energy. The combination of low HDL, high LDL, and high triglycerides can increase a person’s risk of heart attack and stroke.
What is the problem with high blood pressure?
Hypertension, or high blood pressure, occurs when a person’s blood pressure is consistently higher than normal. This means the heart has to work harder to pump blood around the body. If a person has high blood pressure, they are at increased risk for conditions such as the following:
heart disease
heart attack
stroke
kidney disease
Can fish oil lower cholesterol?
The effect of fish oil on cholesterol is controversial. Older information from the American Family Physician journal indicates that omega-3 fatty acid supplements may lower a person’s blood triglyceride levels. However, the authors note that omega-3 fatty acids can also raise a person’s LDL levels. In contrast, research conducted in 2021 linked increased DHA blood levels to reduced LDL levels. Additionally, researchers found that fish oil supplements did not raise LDL levels.
However, this study mainly concerns men with normal blood lipid levels. Further research is needed to confirm these results.
Another 2021 study looked at the effects of combining cod liver oil supplements with the cholesterol-lowering drug rosuvastatin. People who took a combination of cod liver oil and rosuvastatin had a greater reduction in cholesterol than people who took rosuvastatin alone.
Research from 2017 claims that eating fresh fish is more effective at lowering cholesterol than fish oil supplements. Researchers found that people who ate 250 grams (g) of farmed trout twice a week at lunch and dinner for 2 months had:
a reduction in LDL levels
an increase in HDL levels
a reduction in triglyceride levels
a reduction in total cholesterol levels
Researchers also found that people who took 2g of an omega-3 supplement daily saw their LDL levels rise after 2 months.
Taking omega-3s can help lower very high triglycerides, greater than or equal to 500 milligrams per deciliter (mg/dl). People can take 4g per day of EPA plus DHA or EPA only, either alone or with cholesterol medication. A person with high cholesterol should consult a doctor before beginning to take any supplements or changing their diet. Supplements cannot replace prescription drugs.
Can fish oil reduce high blood pressure?
3g of omega-3s a day can lower a person’s blood pressure. A 2022 meta-analysis concluded that people consuming 2–3 g per day of EPA and DHA from Safe Source had an average reduction in systolic and diastolic blood pressure of about 2 millimeters of mercury (mm Hg). People with hypertension had a greater reduction in blood pressure when taking omega-3s than people with normal blood pressure.
Sources of fish oil
Fish and other seafood contain fish oil. The amount of omega-3s can vary depending on the type of fish.
Oily cold water fish contain high amounts of omega-3s. These fish include:
the salmon
mackerel
the tuna
herring
sardines
Low-fat fish, such as cod, shellfish, have a lower content of omega-3 fatty acids.
Some foods may contain added omega-3s, such as:
Vegetable oils contain ALA, another form of omega-3 fatty acid. ALA is present in:
linseed oil
soybean oil
Nuts and chia seeds are also good sources of ALA.
However, a 2019 paper suggests that the body is only able to convert about 5-8% of ALA to EPA, suggesting that other sources may be more beneficial.
How to add fish oil to the diet
A person can consume fish oil through the foods they eat or in supplement form, or consume 1.1–1.6 g of safe-source omega-3s per day. That is to say consume two servings of 80 to 110g of fish per week. Fish oil supplements typically contain 300 milligrams (mg) per capsule. However, the amount of omega-3s in fish or supplements can vary.
How much fish oil is safe?
There is no recommended upper limit for omega-3 intake. However, taking 900 mg of EPA and 600 mg of DHA daily for several weeks can reduce a person’s immune function.
Additionally, taking 2-15g of EPA or EPA plus DHA daily can increase a person’s bleeding time. However, a combined daily dose of 5g of EPA and DHA is a safe amount to take over a long period of time.
Additionally, people with cardiovascular disease (CVD), or those at risk for CVD, may have a slightly increased risk of irregular heartbeats after taking 4g of omega-3 supplements daily for several years.
Other Health Benefits
Fish oil may have other health benefits, including:
a reduced risk of death from heart disease in people who eat seafood at least once a week
a moderate reduction in the risk of ischemic stroke in people who eat fish
relief of symptoms of rheumatoid arthritis in people taking fish oil supplements.
Side effects
The side effects of taking omega-3 supplements are usually mild:
an unpleasant taste
bad breath
smelly sweat
headaches
diarrhea
Possible interactions
Omega-3 supplements may interact with certain medications. High doses of omega-3 supplements can cause bleeding when taken with blood-thinning medications.
If a person is taking other medications, they should consult a doctor before taking omega-3 supplements.
Other foods beneficial for cholesterol and blood pressure
If a person wants to lower their cholesterol and blood pressure, they may benefit from eating the following foods:
fruits and vegetables
legumes, such as kidney beans, lentils, or chickpeas
poultry
lean meats
fish
vegetable oils
low fat dairy products
Whole grains
unsalted nuts
seeds
You may also benefit from reducing your salt and alcohol intake.
Outlook
Treatments for high cholesterol and high blood pressure include lifestyle changes and medication. Living a healthy lifestyle can:
reduce high cholesterol and blood pressure
prevent or delay the development of high blood pressure
improve the effectiveness of blood pressure medications
reduce the risk of heart attack, stroke, heart failure, kidney damage, vision loss and sexual dysfunction.
A person at risk for high cholesterol or high blood pressure should try to maintain a healthy lifestyle. This may include
a healthy diet
exercise regularly
NO SMOKING
limit salt and alcohol intake
get enough rest
reduce stress.
Summary
Fish oils contain omega-3 fatty acids, which can lower a person’s blood pressure. However, their effect on cholesterol levels is controversial. Omega-3 fatty acids are found in fish and seafood, vegetable oils, and fortified foods. The American Heart Association recommends eating two servings of fish per week. Fish oil may also be beneficial for other health conditions, such as rheumatoid arthritis. It usually has mild side effects, although high amounts can cause problems, such as bleeding.
People with high cholesterol or high blood pressure should consult a doctor before beginning to take supplements or changing their diet.
