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Better Nutrition (1989-90)

An introduction to omega-3 fish oils

An introduction to omega-3 fish oils – fish oil supplements

Caroline Mure

An Introduction to Omega-3 Fish Oils

Recent research has proved the value of fish oil supplements. Here’s the information you need to decide what’s best for you.

So much data is available about fish oils but it’s all so confusing. How do you know what’s the truth and how it affects you and your family? In the first part of this 2-part series about essential fatty acids (EFAs), learn why scientists are so interested in fish oils, where to find omega-3 EFAs, how the body converts and uses raw oils, and whether or not you should take a fish oil supplement.

WHY: Scientific Interest

The importance of omega-3 fatty acids was uncovered 37 years ago when researchers first showed a correlation between the incidence of coronary heart disease and fish oil consumption in Norway.

World War II brought with it a drastic reversal in dietary patterns in the Norwegian population. Shortages of dairy products and a substantial increase in fish consumption were the two major dietary changes.

While research conducted at the time attributed a reduction of death from coronary heart disease to an increase of fish in the Norwegian diet, the study generated little attention. It took another research project completed in 1967 — often referred to as “The Greenland Diet” — to capture the widespread attention of health and medical professionals.

From 1963 to 1967, researchers studied the Eskimos of Greenland, increasingly excited over the natives’ low rate of heart disease despite their high-cholesterol, high-fat diet. The Eskimo diet consists almost entirely of whale, seal, fish and game.

Finally, in May 1985, three studies were published in the New England Journal of Medicine (NEJM) that set the omega-3 phenomenon into motion. The first, a 20-year-old Dutch study involving 852 middle-aged men showed heart disease deaths were 50 percent lower for those who ate an average of 1 ounce or more of fish a day compared to those who ate no fish.

The second NEJM study showed a decrease in triglyceride and cholesterol levels with a diet containing commercial fish oil concentrate. In the third project reported in the journal, there appeared to be an anti-inflammatory effect when the diet was enriched with oils extracted from the fatty tissues of fish. Reports of the efficacy of omega-3 fatty acids for a multitude of medical conditions from heart disease to psoriasis to hypertension to arthritis to diabetes have been accumulating ever since.

HOW: Scientific studies

Currently, scientists believe omega-3 fatty acids help prevent heart disease in two ways.

Omega-3 appears to interfere with the way the blood platelets stick together. In diets high in the substance, blood platelets tend to be less able to stick to each other and to blood vessels. In essence, the blood is thinned and therefore flows more freely.

Omega-3 also accumulates in the cells of the artery wall where it produces a chemical that inhibits platelets from clotting.

Thinner blood and fewer clots may translate to less plaque buildup (atherosclerosis) on arterial walls, and less heart disease.

Rheumatoid arthritis sufferers in one study at the Albany (New York) Medical College reported fewer tender joints than a control group following a 36-week regimen of omega-3 fish oil supplements. The fish oil also decreased by 60 percent a substance suspected of contributing to arthritis inflammation.

Hypertension was the subject of a German study in which 14 male patients with mild high blood pressure took part in a two-week diet featuring two cans of mackerel or herring daily. The research showed both diastolic and systolic blood pressure were lowered. Scientists theorized that the thinning of the blood caused less work for the pumping heart.

Some psoriasis patients received mild to moderate relief from inflamed and scaly skin when given daily supplements of fish oil in a recent study at the University of California at Davis. Researchers believe that omega-3 acids inhibit the chemicals associated with inflammation and scaling.

Preliminary investigations of omega-3 in the treatment of migraine headaches, asthma and cancer of the breast and colon also are being conducted.

WHERE: Foods

Omega-3 is a polyunsaturated fatty acid that occurs predominantly in deep sea saltwater fish. It is similar, but not identical to omega-6, the polyunsaturated oil found in vegetables. One of the major dissimilarities between these two fatty acids is an apparent interference in the way platelets — the coagulating components of blood — stick together when omega-3 is present.

Fish richest in omega-3 are those which feed on certain plankton and algae growing in these waters. The omega-3 content of most common fish species in their raw state has been established, but season, size and habitat can affect individual omega-3 content.

Fish rich in omega-3 that are commonly consumed in the United States include salmon, tuna, mackerel, sardines and herring. Fish such as cod, sole and halibut have less than half of the omega-3 of canned white tuna which contains approximately 1,000 mg per 3 1/3-ounce serving.

While the vast majority of all omega-3 is found in fish, a few members of the plant kingdom — including walnuts and wheat germ — contain varying amounts.

Supplements: Are they better?

Sales of fish oil capsules — a supplement that has been available for decades — have soared with the public attention omega-3 research has received. Some controversy has brewed regarding the use of supplements rather than whole fish in the diet. Many doctors feel that prepared meals are the best way to obtain beneficial omega-3 fatty acids while others feel that supplements are superior.

* Most research into the benefits of fish oil has been conducted using the standardized products provided in controlled quantities in capsule form. Few studies report using whole fish.

* Regarding a simple increase in fish consumption, method of preparation is an important factor. For example, fried breaded fish can be nearly 10 percent fat, only 20 percent of which represents omega-3 oil from the fish and the balance of which may or may not be saturated animal fats.

* Credible fish oil concentrates now on the market are guaranteed free from toxic metals, bacterial toxins, chemical residues, pollution by-products and allergens.

* Whole fish, on the other hand, cannot be so guaranteed. Therefore, from a safety point of view, fewer risks are associated with omega-3 dietary supplements than with whole fish.

* A standard dosage of 1 to 5 capsules of standard fish oil capsules can provide between 0.3 and 1.8 grams of omega-3 fatty acids, the amount contained in a 5-oz portion of cold water white or oily fish.

* Advocates of supplements should keep in mind that the use of fish oil capsules does not negate the need for a sensible, well-balanced diet and proper medical care should the situation demand it.

* The advantages of the capsule for people taking fish oil as a health food supplement appear to be as follows according to Harvard Medical School: Relatively tasteless and therefore appealing to people who don’t like the taste of fish or liver oils; Convenient to take; The quality of the oil is stabilized by encapsulation.

Because many Americans cannot, or will not, eat a great deal of the right kinds of fish, Dr. Michael H. Davidson, cardiologist and medical director of River City Medical Center, Chicago, suggests that a fish oil supplement may be a sensible adjunct to a total preventive dietary plan.

“Those who find it difficult to increase their intake of fish may want to consider obtaining the omega-3’s in the form of a supplement, an absolutely safe way to take advantage of their benefits,” he said.

At a recent American College of Cardiology meeting in Atlanta, six papers presented to more than 10,000 doctors examined the benefits of fish oils in supplement form.

“The ability of fish oil supplements to reduce triglyceride levels is well documented,” said Dr. Davidson. However, the beneficial effect of omega-3 fatty acids “involves a complex set of interactions that goes far beyond a straight lowering of cholesterol levels.”

The average American eats only about 14.5 pounds of fish per year, far less than the Eskimos or Japanese consume. Thus, a modest increase in fish consumption, along with a dietary supplement may be the most sensible alternative.

Don’t let the overwhelming availability of information confuse or discourage you. Knowledge is the key to making wise health decisions and once you understand the benefits of fish oils supplements, you’ll be able to include them in your daily vitamin/mineral regimen and thereby maintain optimum health while reducing your risk for heart disease, hypertension, arthritis, psoriasis and possibly migraine, asthma and cancer.

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