TO FISH OR NOT TO FISH?

"Of all the world's enjoyments
That ever valued were.
There's none of our employment
With fishing can compare."

THOMAS D'URFEY, Pills to Purge Melancholy:
Massaniello: Fisherman's Song.

Given the scientific evidence in the previous chapters, it becomes evident that we must load our bodies with omega-3 fatty acids. This can be accomplished by eating a lot of fish, especially, the fatty kind; by taking those golden pills that contain fish oil; or by going directly to marine algae or weeds to find a supply of omega-3 acids. This chapter examines those choices.

A FAT YOU CAN LOVE

The fat in fish is "good" fat. But not all fish have the same "goodness," or fat content. Fish can be categorized as one of two types - those that store fat in muscles such as mackerel, salmon and herring, and those that store fat inside the body such as cod. In the latter category, not highly recommended, most of the fat is found in the liver, not much of which is eaten. Therefore, a serving of cod or similar fish will not provide any substantial amount of omega-3 fatty acids. Also, cod liver oil has excessive concentrations of vitamins A & D ( two teaspoonfuls twice a day is equal to twice the recommended daily allowance of vitamins A & D), which, combined with other sources of vitamin A & D in our diets, can be toxic. Table 13.1 lists, in increasing order, the fat content of selected fish. The highest fat found in any fish is about 16% compared to 30% in sirloin steak. So the fattiest fish is still leaner than other meats.

TABLE 13.1
FAT CONTENT OF FISH (increasing order in each category)

1% or less:

Cod, haddock, northern pike, blue shark, mahimahi, yellow perch, rockfish.

1% to 5%:

Snapper, flounder, walleye, monkfish, Atlantic croaker, pacific pompano, smelt,striped bass, pacific,
halibut, yellowfin tuna, brook trout, skipjack tuna, ocean perch, bluefish, barracuda, Atlantic sturgeon,
Atlantic halibut, sea catfish, chum salmon, swordfish,channel catfish, pacific mackerel, anchovy, pink
salmon.

5% to 10%:

Bonito, Atlantic salmon, rainbow trout, Spanish mackerel, bluefin tuna, cisco, coho salmon, sardine, albacore tuna, sockeye salmon, Atlantic herring, carp, whitefish, lake trout, pompano, pacific herring.

10% to 15%:

Atlantic mackerel, lake sturgeon, butterfish, king salmon, shad, sablefish, American eel, buffalo.

The beneficial effects of fish fat are mainly due to two principal ingredients, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which comprise about 30 percent of the total oil in fish. The quantity of EPA and DHA is higher in "fatty" fish - the fish living in cold water. The fatty acids in cold water fish are less saturated than the fish in warm or fresh waters. The degree of saturation of fatty acids determines how harmful they are for the heart; this applies to fatty acids derived from fish, as well as those derived from vegetable or animal source.

Keep in mind that when you eat fish, you naturally get more than just the "good" fat. Fish also contain many other saturated or unsaturated fatty acids (Appendix A-9), which may be harmful to the body, if fish is eaten frequently.

The choice of fish should depend, besides taste and texture, on the amount of omega-3 acids yielded in proportion to the total calories. Table 13.2 lists the omega-3 content and Tables 13.3 and 13.4 show the best and worst sources for omega-3 fatty acids based on total calories that come with it.

TABLE 13.2
OMEGA-3 CONTENT OF FISH

TABLE 13.3
BEST SOURCES OF OMEGA-3 ACIDS

TABLE 13.4
WORST SOURCES OF OMEGA-3 ACIDS

Sole
Monkfish
Mackerel (except Atlantic/pacific)
Pike
Cod
Haddock
Pompano
Herring
Flounder
Buffalo or Sucker
Bass
Barracuda

Another consideration in the choice of fish is the quantity of cholesterol, especially in shellfish and oysters, which have been historically, but erroneously, considered rich in cholesterol. Table 13.5 lists the current analysis on cholesterol content of selected fish and shellfish.

TABLE 13.5
CHOLESTEROL CONTENT OF SELECTED FISH

Therefore, except for squid, all fish and shellfish are low in cholesterol compared to other meats. The U.S. Department of Health and Human Services and the Department of Agriculture currently recommend as many as four fish meals a week; the average American eats only one. Several recent studies have shown that even two fish meals a week can have a substantial beneficial effect.

Comparing the fish the Eskimos eat and the fish we eat, is not entirely fair, however. The fish consumed by Japanese

fisherman and Eskimos is eaten raw, or only slightly cooked by steam or smoked, whereas we broil, charbroil, fry, bake, poach, bread, or cajun fish before eating it. The cooking process or the trimmings which come with fish can interfere with the absorption of the components of fish.

When fish is cooked with shortening (Table 5.3), either vegetable or animal, frequent use of fish will cause the body to accumulate omega-6 or saturated fats. For example, a 3-oz serving of breaded fish has about 15 grams of fat added to it because of the cooking method. Such additions of fat to the diet defeat the purpose of a fish diet since the beneficial effects of omega-3 fatty acids are related to the ratio of omega-3 to omega-6 acids in the blood and not on the quantity of omega-3 acids alone. This is because the two types of acids compete for enzymes in the blood to produce the PGs. If both types of acids are taken in large quantity, the ratio will remain unchanged in the blood, a situation which can be potentially more harmful than when no fish is taken.

The Eskimos have an added advantage in that the raw fat they consume does not get exposed to air and is, therefore, less rancid and less likely to cause blocked arteries and cancer.

Also, the loss of vitamin A and other antioxidants during cooking renders our fish diet less effective in protecting from cancer. Does that mean, we should raw fish? Not at all; raw fish can cause infections that affect the brain. (Note: Eskimos show substantially higher incidence of psychotic disorder. Could there be a connection with eating raw meat?) Fish should be cooked in a manner which preserves its nutrition and improves taste, yet eliminates the hazardous components. The best method of fish preparation is the moist-heat technique such as poaching or steaming, which adds few calories or carcinogens from burning, and helps retain essential vitamins and minerals. The most popular methods of fish preparation such as open fire broiling (such as mesquite or blackened fish) and frying are the worst when it comes to preserving the essential qualities of a fish meal.

A recent study measured the omega-3 content of an assortment of food served at fast-food chains, including fried fishwiches, fried chicken, hamburgers and pepperoni pizza. All of these products had very low omega-3 content with pizza topping the list. It is suspected that omega-3 acids can be destroyed when food is fried. If one lesson can be learned from this study, it is to avoid fast-food fish sandwiches, which may be foisted upon us as the popularity of fish increases in this country. The fast-food fish sandwich is higher in fat than either a four-ounce hamburger or a white meat chicken entree. The fast food fish sandwich is nearly one-third lower in protein than either hamburger or chicken; breading and frying adds additional calories and cholesterol to fish topping a quarter-pound hamburger.

While scientists explore the effects of cooking on fish, and until the results are in, it is more logical to consume fish oil capsules (4-10 perday) while continuing to increase the use of fish (twice a week) to supply the needed omega-3 acids in the body. In either event, you must also take supplements of vitamin E, whose absorption is reduced by omega-3 fatty acids.

In the following paragraphs we will discuss the advantages of fish oil and then follow up with Tables 13.6 and 13.7, listing the disadvantages of each. Most fish oils contain about equal quantities of saturated and polyunsaurated fats. However, fish oils can be made more unsaturated by a process called de-waxing, where the fatty acids are separated based on their freezing points. If you are taking fish oil supplements, put a few capsules in your freezer. You will find that about half of the oil in the capsule turns cloudy. This is the saturated, or less unsaturated, fraction of the oil. Better processing of oils in the future is expected to reduce their saturated fat content.

Each soft-gelatin capsule of fish oil has about 10 calories and, considering the recommended daily dose, it supplies about 40 to 60 calories compared to about 80 to 250 calories, in a typical 4-ounce fish serving, excluding the trimmings and the calories added due to the cooking process. If you eat fish and take fish oil supplements regularly, you must watch your total caloric intake. You may want to combine low calorie fish (less than 100 calories per meal) such as cod, haddock, perch, pike, rockfish or sole, with fish oil supplements to reduce total calories. Remember, however, that fish low in fat and calories are also low in omega-3 content.

The cholesterol content in fish oil supplements is about 5 milligrams/gram, approximately 10-times higher than in fish. However, the quantity of fish oil consumed, such as 4-6 grams per day gives only about one-half of the cholesterol found in an average seafood meal.

To a purist, who suspects, perhaps rightfully so, that there may be more than just omega-3 acids giving fish its magic healing ability, eating fish is the only way to good health. To a pragmatist, eating fish daily is no fun and he suspects that the fish we buy at the grocery store may contain many undesirable components as well.

A negative consideration in the use of fish is the pollution of marine and fresh waters with heavy metals, pesticides and other industrial chemicals such as PCB (polychlorinated biphenyls) which is banned from production, yet still exists in the environment. The fresh water fish is more likely to be contaminated chemically than the deep sea variety. The maximal allowed tolerance of PCB in fish is only 2 ppm (parts per million), yet even that amount can be harmful to pregnant and nursing women. Fortunately, PCB contamination is decreasing and you need not be concerned about it or other contaminants unless you eat a lot of fish caught in the polluted waters of the Great Lakes. Recently some of the Great Lakes have been cleaned and may not pose a threat as great as they did some years ago. Rainbow trout raised commercially or fished from clear mountain streams generally are safer.

When making a choice, you should also keep in mind that as a matter of convenience and consistency in dosing, many medical investigations have used fish oil supplements in place of fish diet to study the effect of omega-3 acids on the body. Many scientists who are involved in doing research on omega-3 fatty acids themselves take these capsules along with fish.

It is best to start slowly to determine tolerance to such a regimen. Start by taking two capsules per day, one with each meal during the first week. If no discomfort is felt, you can increase the dose to four to six capsules per day, taken over the course of the day but always with a meal, to assure maximum absorption (food in the stomach causes release of intestinal juices which help absorption of oils). Taking fish oil capsules on an empty stomach may cause local discomfort.

As expected, the purists and the fish industry are heavily promoting the use of fish, whereas the fish oil industry, an offshoot of natural health food industry and the soft gelatin capsule manufacturers, is pushing the use of fish oil supplements to keep our arteries supple and and hearts beating.

The debate has heated up during the past few months as several natural health food suppliers have started promoting fish oil. Many noted scientists are totally opposed to the idea of using fish oil supplements. An equal number of scientists would not leave home without their golden pills. Based on information in this book, you should be able to decide for yourself. The following tables list disadvantages to each.

TABLE 13.6
DISADVANTAGES OF EATING FISH

Allergic reactions: due to fish proteins.
Microbiologic contamination: raw shellfish can cause hepatitis or food poisoning.
Chemical contamination: Many carcinogenic chemicals and pesticides are frequently found in lake fish.
Carcinogenesis: due to rotten fish (free radicals).
Heavy metal poisoning: mercury, iron, copper, zinc or selenium, specially in crustaceous fish or mollusks.
Vitamin overdosing: vitamin A & D.
Monounsaturated fatty acids: gadoleic and cetoleic acids in fish can make heart "fatty"; several other undesirable fatty acids also exist in fish.
Variable quantity of omega-3 acids: fish processing, preservation.
Loss of omega-3 acids during cooking: the vitamin loss during cooking ranges from 10-50%.

TABLE 13.7
DISADVANTAGES OF TAKING FISH OIL SUPPLEMENTS

Missing other essential components.
Incomplete absorption: especially in diseases of fat malabsorption.
Local effects: stomach or intestine irritation or allergic response possible.
Regurgitation: after taste.
Vitamin absorption: reduces absorption of fat soluble vitamins such as E.
Chemical contamination: possibly in a more concentrated form; also, contaminants from the process of manufacturing.
Prolonged bleeding times: interaction for patients on anticoagulant therapy; possible problems in surgery and injuries.
Excessive caloric intake: equivalent calories to other oils; 10 g/day is 36,000 calories per year.

The world currently produces about 2.5 billion pounds of crude fish oil; the U.S. production of 250 million pounds is primarily exported since the government regulations will not allow it to be used here. The U.S. market alone should hover around one billion pounds of crude oil per year, allowing about 5 grams of oil per day for each citizen. Considering the current retail cost of about 5 cents per one gram capsule, this represents a $ 24 billion market in the U.S. and a half a trillion dollar market worldwide. The U.S. stands an excellent chance of becoming the world's largest exporter of oil, a crude of a different kind.

FISH OIL COMPONENTS

The beneficial components of fish oil, particularly EPA and DHA, are being studied by major pharmaceutical companies for possible use as drugs in the treatment of the various ailments already discussed. Also, these acids are now prepared in an ester form (a chemically modified form), which is purported to be better absorbed and tolerated. It won't be very long until we see EPA and DHA fortified products appearing on the market. However, the arguments presented against the use of fish oil over fish are also applicable here: the EPA and DHA alone may not be as effective as the complete oil, whose additional components may either improve the effectiveness of EPA and DHA or provide unique actions of their own.

Most of the commercial fish oils contain 180 milligram of EPA and 120 milligram of DHA per gram of oil. Since EPA is more important than DHA in modfiying eicosanoids in the body, the best fish oils have highest concentration of EPA Table 13.8 lists the EPA and DHA content of various fish oils; this should be of lesser concern when eating fish since the total quantity of EPA and DHA in fish also depends on the percentage of fat.

TABLE 13.8
EPA/DHA CONTENT(%) OF FISH OILS

Notice that fish like Mexican anchovy are extremely high in total omega-3 concentration but have very little EPA. Salmon has generally high quantities of omega-3 fatty acids because of its fatty nature, even though the concentration of acids is low. Fish high in DHA may be recommended for children who need larger supply of DHA.

DO WE REALLY NEED EITHER?

There are alternate sources of omega-3 acids available abundantly in nature. Various omega-3-rich marine plants such as chlorella (sp. minutissime) or plankton are good sources, which can be a substitute for fish oil. These marine vegetables, along with the more commone ones we know, can be processed directly into foods, ala tofu, at a much cheaper cost than extracting oil from fish. Linseed, soybean and rapseed oil also provide omega-3 fatty acids but these are of the type which is not as effective as the omega-3 fatty acids found in fish (Table 13.9). It should be remembered that fish is merely a storage medium for omega-3 acids; it can not produce these acids. For example, cultured catfish raised on soybean meal has very little EPA or DHA.

The fish derive their supply of omega-3 acids from marine plants; smaller fish are eaten by larger fish, which are in turn eaten by even larger fish or mammals like whales, whose blubbers end up on the dinner table in remote igloos some 300 miles north of the polar circle on Greenland's barren west coast. And that's how Eskimos benefit from the vegetables in the sea. Do we have to go this long route to obtain our supply of omega-3 acids? Not necessarily. We can go straight to the source of omega-3 acids (Table 13.9) and cut out all the fish in between. But, would eating algae be as much fun as a steamed salmon? Quite possibly. Ask a salmon.

TABLE 13.9
SOURCES OF OMEGA-3 FATTY ACIDS

The vegetable source of omega-3 acids are quit limited. Also, the type of omega-3 acids found in terres erial plants are of less benefit to health (EPA and DHA a e best for health). However, marine plants have great abun ance of omega-3 acids. Can we harvest them? Most definitely. There are also unlimited possibilities with genetic engineering of plants to produce omega-3 fatty acids.

Is it possible that we may have overlooked other sources of omega-3 acids in plants which are not generally part of our food? There is a need to examine plants which grow in colder and moist climates for their omega-3 content. In the meantime, the seabed is full of heart-comforting weeds and we no longer need to feel gulty about cultivating weeds.

The chemical synthesis of omega-3 fatty acids is likely to yield highly purified forms of these acids in sufficient quantity to supply the entire world. However, any significant increase in our omega-3 intake would come only if our routine diets are made abundant in omega-3 fatty acids. One way to accomplish this would be to fortify the cattle and poultry feeds with omega-3 acids. This will allow beef and chicken meat to serve the same purpose as does the blubber for the Eskimos. Beef, because of its fatty nature, would be an ideal source to store omega-3 acids.

HEALTH FOODS

The race is on. It should not come as a surprise to anyone to see a plethora of health foods containing fish oil or its components hit the markets. And with that will come claims of ultimate superiority of one product over another. New formulations of fish oils will probably contain egg white, refined lecithin, soybean sterols, apple fiber, vitamin E, and garlic as additives to improve efficacy of the active ingredients. It will interesting to see the imaginative products developed from fish oil in the future. Some recommendations include DHA fortified infant formula, deodorized cooking oils derived from fish or sea vegetation, EPA and DHA based artificial milk, meal replacement plans based on marine algae, etc.