Shattering a myth: fish and disease. Seafood may be responsible for many ailments which the medical profession has been unable to diagnose successfully

Nutrition Health Review, Spring, 1991

Shattering a Myth: Fish and Disease

Q: What is the basis of the belief that

eating fish can reduce heart disease?

A: Atherosclerosis is characterized by accumulation

of fat deposits in the arteries

leading to clogging of blood flow and

subsequent insufficient supply of oxygen

to the heart. Advocates of adding an

abundance of fish to the diet suppose that

the presence of omega-3 will provide an

antidote.

Fish and other forms of seafood are high

in cholesterol. Whatever benefits omega-3

can provide are diminished by the

addition of cholesterol into the bloodstream.

When the serum cholesterol level

is raised, the liber's ability to modify or

eliminate the substance is diminished.

Q: Fish and seafood have always

enjoyed the reputation of being low

in cholesterol. How do they compare

to other foods?

A: All animal-based foods contain cholesterol.

Only vegetarian foods are cholesterol-free.

The cholesterol content of seafood varies.

Some varieties of fish and shrimp are

second only to raw egg yolk in cholesterol

content by weight. Somehow the myth

persists that fish is cholesterol-free.

Q: Not long ago, pharmaceutical companies

extolled the virtues of fish-oil

pills to be taken with each meal to

ensure against stroke and heart

attacks. What happened to that fad?

A: Medical reports, based on well-founded

studies, implicated fish oil as a serious

problem for diabetics. Also, the substance

proved to be dangerous for people who

suffered thinning of blood caused by fish-oil

ingestion.

Q: Many observers who favor fish consumption

acknowledge the problems

of pollution. They are optimistic,

however, about the prospects of "fish

farming" whose ability to control the

condition of the waters in a controlled

environment could eliminate

contamination concern. How true is

this assumption?

A: Mass breeding of fish can stimulate

infections among the colonies. Fish

farmers are attempting to protect their

investments by feeding the stock antibiotics.

Without doubt, these drugs will be

passed on to fish eaters in whom antibiotic-resistant

strains of bacteria will eventually

flourish.

Q: Many people are under the impression

that seafood is low in calories.

Is this enough to overcome other

problems it poses in weight reduction?

What about sodium content?

A: All forms of fish are high in sodium. Some

forms of processed fish are making their

appearance as "imitation" crab meat,

lobster, etc. They are known as Surimi

in the trade and made of white fish

(pollock), which is extensively processed

with infusions of salt. Imitation crab has

been known to contain 841 milligrams of

sodium in a 3 1/2-ounce serving - enough

sodium to exceed one day's limit. Many

species of fish are actually high in calories

because of their fat content.

A: How do fish and shellfish become

contaminated?

A: The primary source of contamination is

the environment from which the creatures

are harvested. Many of the earth's waters

are polluted with sewage that may contain

human waste and other organisms.

Although cooking sometimes destroys

germs, the likelihood of infection persists.

Shellfish, especially, can be high in such

organisms because their habitat is stationary

and the breeding ground is ideal for

proliferation of microorganisms.

Other sources, of course, are the processing

methods that include poor food handling

through the use of hand, utensils, and

equipment. Improper temperature maintenance

is another hazard in the production

of such foods.

Q: There are rumors that many purveyors

of fish and seafood are involved

in "cover-ups" to camouflage spoilage.

How prevalent is this practice?

A: Many cases of "freshening" seafood are

legal and unhealthful. The Food and Drug

Administration permits the use of sulfite

treatment within prescribed limits. The

agency also stipulates that the presence

of sulfites be revealed on the label of

packed shrimp, for example. Owners of

fish-processing plants have been indicted

for using nitrates to freshen rotting fish.

Ruth Winters in her recent book, Poisons

in Your Food, recounts such an incident

in which a fish-processing firm was

punished by a suspended sentence and a

fine. The child who consumed the posioned

fish died.

Q: Are the reports of poisoning by the

use of raw fish exaggerated?

A: The facts are that such illnesses are

underreported. Worm infections are often

missed by diagnosticians. A young man

admitted to a hospital for appendicitis

after complaining of violent abdominal

pains was dutifully opened surgically for

removal of the infected organ. Instead,

several worms were found in the neighboring

tissues. He had eaten raw fish the

previous day.

Q: Why are seafood products so much

more susceptible to contamination

than beef and chicken?

A: Perhaps the time lapse determines the

speed with which the dead creature

deteriorates. Beef and chicken are usually

processed at the source of slaughter. Fish

die soon after they are removed from

water, and the decaying process begins

almost immediately.

Q: How prevalent is paralytic poisoning

among seafood users?

A: Microscopic algae known as dinoflagellates,

present in shellfish, produce a toxin that

causes shellfish poisoning. The results are