Fish Oil Protects Against Heart Disease, Other Ills, and Early Death

By Vera Tweed

Last Updated: November 11, 2024

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You may know that fish can be a healthy food. But did you know that people who regularly eat fish live longer, healthier lives?

In fact, recent research shows that eating oily fish, such as salmon, sardines, or herring, can add nearly five years to your life.^[1] But there’s a catch: It will take more than a few fish dinners to get the benefit.

A longer life comes from routinely eating the right kinds of fish, prepared the right way (not fried), over a period of years. In addition, the fish meals need to be part of an overall healthy diet.

Most people haven’t been eating this way and need to make up for a shortfall. Taking fish oil supplements can help you to reap the benefits.

Why Fish Oil Is Essential

Researchers have studied fish oil for the past 70 years, initially finding a connection to a healthy heart. But more recently, studies have uncovered a wide variety of benefits as the oil has become better understood.

Fish oil contains specific omega-3 fats: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). These have many beneficial effects because our bodies need them for a variety of important functions.

To start, omega-3 fats are key building blocks of every cell in the human body. They support the structure of each cell and enable communication between cells, which are basic necessities for our bodies to function properly.

Omega-3 fats also regulate many internal processes. Early in life, these fats are necessary for normal brain development, and as we get older omega-3s help to keep us healthy through the years.^[2]

5 Important Benefits of Fish Oil

Here are five ways that a fish oil supplement can enhance health:

1. Reduced Heart Disease

The omega-3 fats in fish oil help to regulate blood pressure, lower harmful chronic inflammation, and protect against all types of heart problems and stroke.

Studies have shown that omega-3s lower triglycerides, which are blood fats that are tested along with cholesterol and are harmful when elevated. As a result of the evidence, in 2002, the American Heart Association began recommending fish oil to lower triglycerides with doses between 2 grams and 4 grams of omega-3s daily.^[3]

Research also shows that omega-3s help to prevent plaque in arteries or, where it has already begun to develop, slow the progression. Reduced risk of stroke is another potential benefit.^[4]

Other studies have found that omega-3s from fish oil help to maintain healthy blood clotting and heart rhythms and reduce the odds of sudden death from a heart attack. More than half of sudden heart-related deaths occur in people who seemed healthy and had never been diagnosed with any type of heart disease.^[5]

2. Better Mental Function

Cultures that routinely eat fish tend to have better memory and other mental functions as they age. And a study of older people showed that switching to a diet that includes fish can produce benefits in a few months.

Researchers compared two dietary changes in a group of 57 healthy older people. Half added canned sardines and a fish spread to their diets and the other half added meatballs and soy foods. Memory and other mental skills of people in both groups were tested at the start.

After study participants had followed their modified diets for 12 weeks, the memory and other mental performance tests were repeated. Those who had been eating sardines and fish spread scored significantly better, but those eating meatballs and soy foods showed no improvement. Researchers estimated that the fish group consumed about 2.2 grams of omega-3s daily.^[6]

Other studies have found that inflammation and damaged cells in the nervous system contribute to mental decline in older people. Overall good nutrition — and especially omega-3s from fish oil — can help to decrease inflammation, reverse some of the damage, improve memory and overall mental performance, and help to ward off dementia.^[7]

A specific therapeutic dose of fish oil for mental improvement has not been identified, and individual responses to supplementation vary.

3. Protection Against Diabetes

Omega-3 fats can help to protect against type 2 diabetes or improve health if the disease has developed. There are several ways this works.

High triglycerides are known to increase risk for diabetes, even when other health markers are in healthy ranges.^[8] Omega-3s are proven to lower triglyceride levels.

In addition, elevated inflammation and poor insulin sensitivity are indicators of higher risk for diabetes, and they also contribute to worsening of the disease. Omega-3s help on both counts — they reduce chronic inflammation and enhance insulin sensitivity.^[9]

Insulin sensitivity is a measure of how well your body metabolizes carbs: sugars and starches. Healthy insulin sensitivity enables carbs to be burned to generate energy. However, when insulin sensitivity is poor — a condition known as insulin resistance — carbs are not metabolized properly. This leads to less energy production and more fat storage, which in turn contributes to chronic inflammation and higher odds of diabetes (and heart disease).

In short, good insulin sensitivity is a key to steering clear of diabetes, stopping its progression, or even reversing the disease.

Studies have shown that people who eat a lot of fish, rather than meat, have better insulin sensitivity^[10] and less type 2 diabetes.^[11] Other research shows that high blood levels of omega-3 fats, whether they are obtained by eating a lot of fish or by taking fish oil supplements, correlate with healthy insulin sensitivity, healthy blood pressure, and less harmful chronic inflammation.^[12]

Another Beneficial Fish Oil Ingredient

In its natural state, fish oil contains another beneficial fat: omega-7, also called palmitoleic acid. Numerous animal studies and some human trials have found that omega-7 is beneficial.

One study of 100 people at high risk for diabetes found that a slight increase in omega-7 levels made a significant improvement in insulin sensitivity for most study participants, which helps to prevent diabetes or reverse its course.^[13] And another study found that eating macadamia nuts, which are exceptionally high in omega-7 fat, improved cholesterol.^[14]

Most fish oil supplements are formulated to provide a higher concentration of omega-3s and do not contain omega-7. But some supplements do contain both. Provinal is one patented form of omega-7 from fish that has been purified and tested.

4. Relief from Joint Pain

Osteoarthritis is a leading cause of joint pain and disability. Fish oil can provide some relief.

One study compared the effects of 2,000 mg of omega-3s from fish oil and a dummy pill on 152 people. Those in the study were over age 65, overweight or obese, and suffered from pain in the knees, shoulders, and/or lower back. In most cases, the pain was chronic.

Supplements of fish oil or dummy pills were taken for 16 weeks. At the end of that period, those taking fish oil reported, on average, 42 percent less pain than those taking dummy pills.^[15]

According to the researchers, one way that fish oil helped was by improving microcirculation in the joints. In plain English, this means that tiny blood vessels around joints became more flexible and more efficiently delivered oxygen and nutrients. This led to healthier cartilage and less pain. In addition, inflammation was slightly reduced.

In people with rheumatoid arthritis, studies have found that fish oil decreases inflammatory signals in the human body that cause the symptoms of the disease. Through this mechanism, fish oil can reduce swelling and tenderness in joints.^[16]

5. Healthier Skin

Walk into any drugstore and you will see thousands of creams, lotions, balms, and serums to treat various skin problems and give you a healthy glow. But no matter how many potions and lotions we use, our skin will be a sign of what’s going on inside our bodies.

Inflammation plays a big role in psoriasis, dermatitis, acne, and skin damage from the sun. Studies show that by calming inflammation in skin cells, fish oil can reduce symptoms of these conditions.^[17]

Fish oil can also help to heal skin ulcers and other wounds, which is especially important for diabetics. In the case of sun exposure, fish oil does not replace the need for sunscreen but can make skin more resistant to damage. It can also help to reduce the side effects of acne drugs.^[18]

How to Benefit from Fish Oil

At times, researchers have been baffled by the fact that specific dosages of fish oil did not always produce the same results. As more studies were done, it became apparent that different diets, body weight, overall health status, and genetics influence how efficiently each of us absorbs and uses omega-3s.

What matters most is the level of omega-3s in a person’s body. Among most Americans, those levels are too low and raising them is the key to improving health and longevity. How do you measure omega-3 levels? With a simple blood test.^[19]

The Omega-3 Index

The omega-3 index test measures levels of omega-3s in red blood cells. Research with more than 3,000 people has shown that a level of at least 8 percent is optimal. However, among people who eat the usual American diet, with little or no fish and no fish oil supplements, the likelihood of having an optimal level is almost non-existent — about 2 percent.^[20]

An omega-3 index test can give you a picture of your personal omega-3 levels and needs. But there is also research that provides an idea of the doses of fish oil supplements needed to achieve an optimal range.

How Much Fish Oil Should I Take?

A study of more than 1,400 people estimated that, on average, it would take supplementing with approximately 2,000 mg daily of omega-3s (EPA and DHA), for 13 weeks, to raise levels to the optimal 8 percent or more. Higher doses would raise levels more quickly.^[21]

How to Read Supplement Labels

Labels on the front of supplement bottles may give an amount of total fish oil per serving, such as 1,000 milligrams (mg), which is the same as 1 gram (g). But the key omega-3s — EPA and DHA — are only part of the fish oil. And the specific quantities of omega-3s may only be found in the Supplement Facts section of the label, on the back or side of a product.

The amounts of EPA and DHA are listed separately, and they vary from one product to another. Look for the combined amount of EPA plus DHA per serving. And consider looking for a product that also contains omega-7.

Can I Get Enough Omega-3s from Fish?

In theory, perhaps, but it isn’t likely in practice. In Japan, where people eat lots of fish throughout their lives, optimal levels of omega-3s are common. But if fish hasn’t habitually been one of your staples, you’ll need extra omega-3s to get your levels into a healthy range.

This doesn’t mean you shouldn’t start eating more fish. You should, notably those fish high in omega-3s such as salmon, herring, mackerel, and sardines — baked, grilled, or poached, but not fried. Tuna is another good source but can be high in mercury so it’s best to eat it only occasionally.

That said, a recent study found that even if you follow the American Heart Association recommendation of eating at least 2 servings of fish per week, it isn’t enough to raise levels of omega-3s to an optimal range.^[22]

Does Fish Oil Have Side Effects or Risks?

Some people experience gas or burps after taking fish oil, and there have been rare reports of some stomach upset. To avoid digestive problems, take fish oil with food, preferably with fatty food. Fish oil can be taken at any time of day.

The Bottom Line

The fish with the highest amounts of omega-3s are not America’s most popular foods. Therefore, fish oil supplements, taken regularly as part of a healthy diet, are a practical way to achieve the optimal omega-3 levels that will enhance health and help you live longer.

References

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