Omega-3 Fatty Acids From Fish Oil Protect Your Heart, Brain and Overall Health

Cholesterol and fat were onced believed to be the unquestionable culprits in cardiovascular disease (CVD). We now know that many factors contribute to cardiovascular disease and that certain fats are not only good for you, but they are essential for optimal health. Thanks to the early work of Dr. H. M. Sinclair of Oxford University, we also know that fish oil—which contains particular types of fats called omega-3s —has been shown to play a major role in preventing cardiovascular disease.¹

Fish oils are rich in omega-3s

Hundreds of studies have demonstrated the importance of omega-3-rich fish oils in the diet. They have had favorable effects on insulin resistance, cardiovascular health, type 2 diabetes, autoimmune disease, and chronic inflammatory disease.²³ Numerous population studies like the ones previously discussed correlate an omega-3-rich diet with a significantly lower risk of heart disease. The oils have even been shown to help prevent the onset of a heart attack.⁴

Although the mechanisms responsible for omega-3 fatty acids’ reduction of CVD risk are still being studied, research has shown that consumption of fish and fish oil supplements helps:

• Decrease risk of sudden death and arrhythmia
• Decrease thrombosis (blood clots)
• Decrease triglyceride levels
• Decrease growth of atherosclerotic plaque
• Improve arterial health
• Lower blood pressure⁵

Fish oils have also been shown to protect against and/or ameliorate:

• Memory and cognitive dysfunction
• Eczema and psoriasis
• Arthritis and inflammation
• Migraine headaches
• Crohn’s disease
• Hypertension
• Some forms of cancer
• Lupus
• Arrhythmias⁶

Essential fatty acids—the healthy fats you can’t live without

Essential fatty acids (EFAs) are critical to every cell of your body and essential for anti-aging. In fact, your body needs EFAs just like it needs other essential vitamins and minerals to help prevent and treat numerous diseases. But since the body cannot manufacture them, EFAs must come from the food you eat and/or nutritional supplements. There are two main classes of essential fatty acids: omega-3 fatty acids and omega-6 fatty acids. Omega-3s include Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA), and alpha Linolenic acid (ALA).

A Smarter Fish Oil

Omega-3 fatty acids—EPA and DHA—are considered “long chain” fatty acids and are found primarily in cold-water fish (salmon, mackerel, cod, herring, rainbow trout, sardines, anchovies or eel) and fish oil supplements. ALA is a “short chain” fatty acid and is found in freshly ground flaxseed or flaxseed oil, dark leafy greens, hemp seed, soybeans, canola, walnut and flaxseed and oils made from those beans, nuts, and seeds.

Omega-6s include Linoleic acid (LA), Gamma linolenic acid (GLA), and Dihomo gamma linolenic acid (DGLA).

Omega-6 fatty acids are found in vegetable oils such as corn, sunflower, safflower, and cottonseed oils.

Note: Most of the sunflower and safflower oils on the market today (even in health food stores) say “high monounsaturate” in the ingredients list. These are genetically modified seed oils even though some labels claim they are organic. And there is very little LA in them. Manufacturers do this now instead of partially hydrogenating the oil, so they can ensure a long shelf life.

What do essential fatty acids do?

EFAs serve as precursors to an entire class of hormones called prostaglandins, which regulate nearly every body function. EFAs nourish the skin, hair, mucous membranes, nerves, thyroid, adrenals, cells, and much more. They provide internal lubrication, keeping the gastrointestinal tract lubricated and aiding in smooth, efficient digestion and elimination. They also control the way cholesterol works in the body, and play a key role in the functioning of the brain, and in regulating inflammation and healing, the immune, digestive, reproductive, and cardiovascular functions.

Our very first EFAs come from mother’s milk, which is a source of EPA and DHA—both essential to brain development. These fats are not found in cow’s milk, which is one of the prime reasons breastfeeding is preferred over formula feeding. If a baby must take formula, it is especially important that the formula is enriched with DHA. After weaning, omega-3s must be derived from food or dietary supplements.

The right balance

A balance of omega-3 and omega-6 fatty acids is essential to promoting and maintaining health. According to Artemis Simpoulos, M.D., President of the Center for Genetics, Nutrition and Health in Washington D.C. and co-author of The Omega Plan (Harper Collins, 1998), “The ratio of omega-6 to omega-3 fatty acids in the Western diet today is betweeen 10-to-1 and 21-to-1, whereas the diet humans evolved on had a ratio of 1-to-1. One of the most important medical findings of recent years is that eating a balanced ratio of EFAs brings your diet back in sync with your genes and helps you experience optimal health.”

Current thinking is that omega-6 fats and omega-3 fats need to be balanced in the diet at a ratio of 1-to-1 or 2-to-1. And the best way to do that is to supplement your diet with an excellent fish oil nutritional supplement, and/or eat fish several times a week.

How do omega-3 and omega-6 fatty acids work in the body?

These two classes of polyunsaturated fatty acids should be distinguished because they are metabolically and functionally distinct, as well as having opposing physiological functions, says Simpoulos. “Omega-3s and omega-6s work differently in the body. When they’re in balance, they’re both very good. When the omega-6s are in excess, they become bad.”

Here’s what happens: omega-3s produce hormone-like eicosanoids that are anti-inflammatory. These eicosanoids help support normal blood pressure by relaxing the arteries and blood vessels and decreasing blood lipids. They also decrease blood clotting factors and support immune function.

Omega-6s, however, can produce both anti-inflammatory and/or inflammatory and vasoconstricting eicosanoids. To oversimplify just a bit: omega-6s are good for you if you take them in the right amount with omega-3s. However, in the absence of omega-3s they can be very bad indeed.

Too many omega-6s in your diet in the absence of sufficient omega-3s can produce potent inflammatory agents that set the stage for autoimmune diseases such as arthritis, and a host of other health problems.

But the eicosanoids produced by omega-3s help inhibit the production of these inflammatory agents. To clarify further: LA gets made into GLA, then into DGLA and then into either AA (arachidonic acid), which then gets made into inflammatory eicosanoids, or the DGLA gets made into a series of VERY BENEFICIAL eicosanoids that have, among other effects, antiviral and anti-vaso-constrictive effects.

What determines whether DGLA goes to AA or to the beneficial eicosanoids?

Well, low EPA and high insulin will cause DGLA to go to AA (that’s why Americans have such high levels of AA; we make it in our own bodies). If you have good levels of EPA and low insulin (by doing an insulin-smart diet) then your body will NOT make AA from DGLA … instead the DGLA will get made into the beneficial eicosanoids.

So, in a word, to turn omega-6 fats into a positive biological reaction, you take omega-3s! Confusing enough yet?

Even though omega-6 is an essential fatty acid, too much of it can do more harm than good. Insulin encourages the conversion of (omega-6) Gamma linolenic acid (GLA) into arachidonic acid. So does consumption of sugar, alcohol, saturated fats and trans-fatty acids, diabetes, aging, stress, and some prescription medications. Low levels of EPA also strongly encourage the conversion of omega-6 into AA. In essence, everything about the modern Western World diet encourages the conversion of dietary LA into heart disease causing AA! The solution? Reduce your intake of refined carbohydrates and take fish oil!

According to Barry Sears, Ph.D., author of several books including The Zone and the The Omega Rx Zone: The Miracle of the new high-dose fish oil (Harper Collins Publishers), “Excess arachidonic acid is your worst biological nightmare. It’s the building block for bad eicosanoids, including A2 (which causes platelet clumping), PGE2 (which promotes pain and depresses the immune system) and leukotrienes (which promote allergies and skin disorders). In fact, arachidonic acid is so potent and so dangerous that when you inject it into the bloodstream of rabbits the animals die within three minutes.”⁷

On the other hand, (omega-3) Eicosapentaenoic acid (EPA) encourages the conversion of GLA into good prostaglandins. GLA can go either way. So to make sure it goes the right way, reduce your consumption of starchy foods and eat fish or take fish oil supplements! In one study, corn oil, which is rich in omega-6s, increased the risk of colon cancer, but fish oil, rich in omega-3s, seemed to inhibit both the development and progression of cancer.⁸

Also, Australian researcher Leonard Storlien found that people who have low levels of omega-3s and high levels of omega-6s in their muscle cells are more likely to be obese and insulin resistant.⁹

A study published June 21, 2007, in the Journal of Clinical Investigation suggests that diets high in omega-3 fatty acids—especially the “long-chain” forms found in oily fish—might give men an edge against prostate cancer.

A Smarter Fish Oil

And while the exact mechanism driving the purported anti-cancer effect is still unclear, the researchers do have a couple of different theories. One leading theory contends that specific cellular enzymes metabolize omega-3s in ways that retard malignancy. Another theory is that [long-chain] omega-3 fatty acids might modulate apoptosis—a form of programmed cell death. Senior researcher Yong Chen, a professor of cancer biology at Wake Forest University School of Medicine in Winston-Salem, N.C, said it’s important that consumers realize that not all omega-3s are created equal in terms of their potential health benefits.

“In this study, we are only referring to the long-chain form” found in oily fish, such as mackerel, herring, albacore tuna and salmon, he said. Other, shorter-chain varieties can be found in flaxseed and plant sources, but their impact, if any, on cancer is even less clear.¹⁰

Omega-3s protect women against heart disease

A Harvard Public School of Health study released last year evaluated this heart connection in more than 84,000 female nurses, who were enrolled in 1970, and found that those who consumed diets rich in omega-3 fatty acids had the lowest incidence of fatal heart attacks.

In the 16-year period between 1980 and 1996 a total of 1,513 of the nurses either died from coronary heart disease (484) or suffered a non-fatal heart attack (1,029). After adjusting for age, smoking and other known cardiovascular risk factors, the researchers concluded that women who eat fish once a week have a 34 % lower incidence of death from heart disease and a 25 % lower incidence of non-fatal heart attacks. They also noted that both fish and fish oil consumption were associated with a decreased risk of dying from any cause.¹¹

“I have observed triglyceride levels in my patients fall from over 1,000 to less than 200, simply by supplementing with fish oil.”¹²

Supports normal blood lipids

According to Julian Whitaker, M.D., best-selling author of Shed 10 Years in 10 Weeks, fish oil can help prevent heart attack and stroke by discouraging the formation of blood clots. He cites research showing that the regular consumption of fish oil can also reduce blood pressure, cholesterol and triglyceride levels, and states, “I have observed triglyceride levels in my patients fall from over 1,000 to less than 200, simply by supplementing with fish oil.”¹²

Not long ago, the American Heart Association (AHA) issued a recommendation that all Americans should obtain more fish and plant oils in their diets (Circulation: Journal of the American Heart Association, Nov. 18, 2002). The AHA specifically suggests that individuals with heart disease get at least 1 gram of fish oil daily and that people with elevated triglycerides get 2 grams to 4 grams of fish oil daily. The research committee suggests that individuals with heart disease consider taking fish oil supplements if they cannot obtain enough in their diets.

Penny Kris-Etherton, Ph.D., R.D, lead author of the report, said that “Omega-3 fatty acids are not just good fats; they affect heart health in positive ways. They make the blood less likely to form clots that cause heart attacks and protect against irregular heartbeats that cause sudden cardiac death.”

“Not long ago, the American Heart Association (AHA) issued a recommendation that all Americans should obtain more fish and plant oils in their diets.”

The report says that people who have elevated triglycerides may need 2 to 4 grams of EPA + DHA per day provided as a supplement. Even the 1 gram/day dose recommended for patients with existing CVD may be more than can readily be achieved through diet alone, says Kris-Etherton. These people should consult their physician to discuss taking supplements to reduce heart disease risk. Patients taking more than 3 grams of omega-3 fatty acids from supplements should do so only under a physician’s care, since the FDA has noted that high intakes could cause excessive bleeding in some people.

“This is hopeful news as we have found that the effect of omega-3 fatty acids on heart disease risk is seen in relatively short periods of time,” Kris-Etherton says. “The research shows that all omega-3 fats have cardioprotective benefits, especially those in fish.”

Fish oil reduces the risk of sudden death in patients who have recently suffered a heart attack

A group of Italian researchers reported in 1999 that supplementation with fish oil reduces the mortality among patients who have survived a first heart attack. Their study involved over 11,000 heart attack survivors who supplemented with 1 gram/day of fish oil (580 mg of EPA and 290 mg of DHA) for 3.5 years.¹³

The researchers re-analyzed their data five years later in order to determine how the fish oil exerts its protective effects. After just three months of supplementation with fish oil, there was a noticeable difference. The reduction in the incidence of sudden cardiac death accounted for about 57 percent of the total improvement in mortality rates. At the end of the study 2.7 percent of the placebo group participants had died from sudden cardiac death as compared to only 2.0 percent in the fish oil group.

Overall, cardiovascular death (including stroke) at the end of the study was 6.5 percent in the placebo group versus 5.5 percent in the fish oil group. The researchers concluded that fish oils exert their protective effect by regulating the electrical activity of heart muscle cells, stabilizing them so they are resistant to arrhythmias.¹⁴¹⁵

Your brain needs DHA

You’ve heard that fish is brain food—here’s why. DHA is the major unsaturated fat in the brain. This long-chain fatty acid provides the necessary fluid quality to the membranes of the nerve cells so that electrical nerve impulses can flow easily along the circuits of the brain.

But when the brain has low DHA levels, the production of prostaglandins—important regulators of nerve impulses—is destabilized. Consequently, inflammatory prostaglandins build up in the brain, similar to the irritating prostaglandins that cause problems in the joints and digestive tract.

According to Donald O. Rudin, M.D. and Clara Felix, authors of The Omega-3 Phenomenon (Rawson Associates, 1987), “In a susceptible person, the same process that causes spasms in the bowel may trigger spasms of irrational fears, panic, or rage when his or her brain is similarly affected. It may also trigger irrational feelings of euphoria. We may view mental illness as an ‘irritable brain syndrome,’ a cousin of irritable bowel syndrome, irritable esophageal syndrome, irritable ear syndrome (tinnitus and Meniere’s syndrome), and so on,” write the authors.

More recently, low DHA levels have also been linked to low brain serotonin levels, which again are connected to an increased tendency to depression, suicide, and violence. A high intake of fish has also been linked to a significant decrease in age-related memory loss and cognitive function impairment, and to lower the risk of developing Alzheimer’s disease.¹⁶¹⁷¹⁸ One study found that Alzheimer’s patients given an omega-3-rich supplement experienced a significant improvement in the quality of their life.¹⁹

Another study, in the April 18, 2007, issue of The Journal of Neuroscience, suggests that supplementation with omega-3 may help prevent the development of Alzheimer’s as people age.

The researchers at the University of California, Irvine, found that DHA slowed accumulation of tau, a protein that leads to the development of neurofibrillary tangles, one of the two signature brain lesions of Alzheimer’s.

The researchers also found that DHA reduced levels of the protein beta amyloid, which can clump in the brain and form plaques, another kind of lesion associated with Alzheimer’s.²⁰

Omega-3 enhances mood

Several studies have established a clear association between low levels of omega-3 fatty acids and depression. Other studies have shown that countries with a high level of fish consumption have fewer cases of depression. Researchers at Harvard Medical School have successfully used fish oil supplementation to treat bipolar disorder, and British researchers report encouraging results in the treatment of schizophrenia.^212223242526

Ensure a healthy pregnancy and baby with plenty of omega-3s

An adequate intake of DHA and EPA is particularly important during pregnancy and lactation. During this time the mother must supply all of the baby’s needs for DHA and EPA because the baby is unable to synthesize these essential fatty acids itself. 70 percent of the brain’s gray matter is made up of fats and DHA makes up 15 to 20 percent of the cerebral cortex and 30 to 60 percent of the retina, so it is absolutely necessary for normal development of the fetus and baby.

There is some evidence that an insufficient intake of omega-3 fatty acids may increase the risk of premature birth and an abnormally low birth weight. The drain on a mother’s DHA reserves can easily lead to a deficiency and some researchers believe that preeclampsia (pregnancy-related high blood pressure) and postpartum depression could be linked to a DHA deficiency. Experts recommend that women get at least 500-600 mg of DHA every day during pregnancy and lactation … and the easiest way to ensure this intake is to take a good fish oil supplement daily!^2728293031

Omega-3s may help ADHD

There is emerging evidence that low levels of omega-3 acids are associated with hyperactivity in children.³²³³³⁴

British researchers reported in the February, 2002, issue of Progress in Neuro-Psychopharmacology & Biological Psychiatry that learning-disabled children with symptoms of dyslexia and ADHD (attention-deficit/hyperactivity disorder) may behave better and improve their cognitive skills when their diets are supplemented with fish oils.

Lowers risk of asthma in children

Researchers at the University of Sydney have found that children who regularly eat fresh, oily fish have a four times lower risk of developing asthma than children who rarely eat such fish. EPA may prevent the development of asthma or reduce its severity by reducing airway inflammation and responsiveness. Researchers at the University of Wyoming have found that supplementation with 3.3 grams/day of fish oil markedly reduces breathing difficulties and other symptoms in asthma patients.³⁵³⁶³⁷

Eat lots of fish … or take fish oil supplements!

It’s clear that the omega-3 fatty acids are vital to health. If you want to increase your omega-3 fatty acids, you need to make a commitment to eat salmon, mackerel, cod, herring, rainbow trout, sardines, or eel every day. Or, use a high quality fish oil supplement.

How much do you need?

The American Heart Association recommends eating fatty fish at least twice a week. But Dr. Barry Sears recommends up to 2,500 mg EPA and DHA (omega-3s) every day. (EPA + DHA = 2,500 mg.) It’s important to note, however, that only 5 to 20 percent of the fatty acids in fish oil are a combination of EPA + DHA. The rest of the fatty acids in fish oil are saturated fats.

A Smarter Fish Oil

If you only eat fish 2-3 times per week and you want a 2:1 ratio of omega-3 to omega-6 fats, you would have to eat unbelievably small amounts of omega-6 fats. It would be difficult. Plus many conditions require more omega-3 than that. Sears (and many others) recommend a maintenance level of 2,500 mg (EPA + DHA). A 3.5-ounce can of sardines has 1.4 grams, or 1,400 mg of EPA + DHA and a 3.5-ounce serving of salmon has 1.1 grams or 1,100 mg, although a large serving of salmon probably has 2,500-3,000 mg. So every day, you would either need to eat two cans of sardines or a large portion of salmon. Of course, Japanese fishermen eat that much fish and Eskimos eat much more. It is possible to get 2,500 mg of EPA and DHA with fish, without taking fish oil capsules, but if you do, you would be eating almost nothing but fish.

How much DHA and EPA are in fish oil?

The amount of fish oil used in much of the research that has been done provided 3 grams per day of omega-3 fatty acids. This amount is usually found in 10 grams of fish oil. To calculate how much omega-3 fatty acid is contained in a fish oil supplement, add together the amounts of EPA and DHA. For example, a typical 1,000 mg capsule of fish oil provides 180 mg of EPA and 120 mg of DHA (total omega-3 fatty acids=300 mg). Ten of these capsules contain 3,000 mg of omega-3 fatty acids. However, you can find quality fish oil supplements containing higher doses of EPA and DHA.

Safety precautions

Eating fresh fish every day used to be the best way to get high-quality fish oil. Not only is that difficult for most of us living in the U.S., much of the fish now found in the oceans, lakes, and streams contain dangerously high levels of mercury and other toxins.

The health risks of ingesting these toxins may outweigh the benefits of getting omega-3s … since we’d have to eat a lot more fish than may be considered safe.

Supplementing your diet with high quality fish oil capsules is the next best thing to relying on fresh fish. Just be sure that you take a high-quality, fresh product. Check the expiration date on the bottle, and cut open a capsule and taste the oil. If it tastes and smells like fish that’s gone bad, don’t eat it! It is rancid oil. Even the best oil will be fishy and oily but will not have that sharp, bitter, fishy smell of rancid fish oil. Unfortunately, most fish oil supplements are not high quality, so you shouldn’t trust anything from a grocery or discount store.

Conclusion

Research on omega-3s has come a long way, and undoubtedly there are many more exciting discoveries to be made. In the near future, we’ll be learning more about the mechanisms of how they work, and specifically their impact on gene expression, protein expression, and other processes in the body. In the meantime, we can rely on the thousands of studies indicating the immense benefits that omega-3 fatty acids provide … and obtain some of those benefits by eating fish every day, or supplementing our diets with fish oil capsules. It’s probably safe to say that omega-3 just may be the most important single dietary supplement you can take.

Caution: People with clotting disorders or who are taking prescription blood thinners should not take omega-3 supplements unless prescribed by a physician.

 

References