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VICUS.COM (3 Aug.
2000) -- It's no less heroic than the return of Gen. Douglas MacArthur
to The Philippines in 1944, 2-1/2 years after his famous promise,
"I shall return."
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About
egg color
An egg's shell
and yolk color may vary, but color has nothing to do with egg
quality, flavor, nutritive value, cooking characteristics or
shell thickness.
Egg shell color
is determined by the breed of the hen. Breeds with white
feathers and ear lobes lay white eggs; breeds with red
feathers and ear lobes lay brown eggs.
The egg white, or
albumen in raw eggs, opalescent until beaten or cooked, may
take on a yellow or green cast that stems from riboflavin.
Cloudiness in the raw white is present when carbon dioxide in
the egg has not escaped, indicating a very fresh egg.
Yolk color
depends on the hen's diet. Mashes of yellow corn and alfalfa
meal result in medium yellow yolks, while hens eating wheat or
barley yield lighter-colored yolks. A colorless diet of
cornmeal produces almost a colorless yolk.
--Source: American
Egg Board
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It's no less surprising than the Hail Mary touchdown pass by Doug
Flutie that led to the Boston College upset victory over Miami, 47-45,
in 1984. Things are again looking
sunnyside up for eggs, after 30 years of banishment from the American
diet because of concerns over their cholesterol content.
People are eating more eggs, and the poultry industry is expanding the
market by creating healthier designer eggs, high in heart-healthy omega-3
fatty acids and other nutrients.
Equally important are the
data from clinical studies published during the '90s about eggs and
cholesterol. Eggs
are relatively high in cholesterol (about 550 mg
cholesterol/100 grams of fresh eggs), but it appears that
saturated fat in the diet, not dietary cholesterol, is what influences
blood cholesterol levels most. The following examples are
representative of the clinical studies that have exonerated eggs as a
health risk for many Americans.
Effects of dietary fat
and cholesterol on the regulation of cholesterol production by the
body
A group of older men and
women consumed diets high in either polyunsaturated fat (corn oil) or saturated fat (beef
tallow)
with and without the addition of 120 mg cholesterol per 1,000 kcal..
The results showed that one effect of an increase in dietary
cholesterol is a decrease in cholesterol synthesis by the body to
compensate for the change (Jones et al. 1994).
Effects of dietary
cholesterol on LDL and HDL cholesterol
in healthy young women
Thirteen young women consumed zero, one or three eggs per
day. Their bodies compensated for an increased intake of cholesterol
by adjusting the way the cholesterol was handled. Two eggs per day
had little effect on plasma cholesterol levels in the majority of
women studied (Ginsberg, et
al. 1995).
Effect of
"designer eggs" on blood lipids
Twenty-eight men ate
four regular or omega-3 fatty acid-enriched eggs each day for two
weeks. The fatty acid composition of the egg showed no relationship
to the effect of dietary cholesterol on plasma cholesterol levels (Ferrier
et al. 1995).
Effect of two eggs per
day in moderately hypercholesterolemic and combined hyperlipidemic
middle-aged men and women
Participants in this
study had either moderate hypercholesterolemia or
combined hyperlipidemia (elevated
plasma cholesterol and triglyceride).
They consumed either no eggs or two eggs per day as part of a National
Cholesterol Education Program (NCEP) Step I diet. Those who had
elevated plasma cholesterol levels were not more sensitive to dietary
cholesterol compared to people with normal cholesterol levels.
However, middle-aged patients with combined hyperlipidemia appeared to
be more sensitive to dietary cholesterol, and for them, dietary
cholesterol restrictions appear more appropriate (Knopp, et
al., 1996).
Egg consumption and
the risk of coronary heart disease and stroke
In more than 100,000 healthy men and women who were studied for up
to 14 years, there was no evidence of an association between eating
eggs and the risk of coronary heart disease or stroke in either men or
women. Among men and women with diabetes however, increased
egg consumption (more than one egg per day compared with less than one
egg per week) was associated with an increased risk of coronary heart
disease (Hu, et al.,
1999).
Egg
quality
| |
Grade
AA |
Grade
A |
Grade
B |
|
Break-out
Appearance |
Covers
a small area |
Covers
a moderate area |
Covers
a wide area |
|
Albumen
Appearance |
White
is thick and stands high; chalaza prominent |
White
is reasonably thick, stands fairly high; chalaza prominent. |
Small
amounts of thick white; chalaza small or absent. Appears weak
and watery. |
|
Yolk
Appearance |
Yolk
is firm, round and high. |
Yolk
is firm and stands fairly high. |
Yolk
is somewhat flattened and enlarged. |
|
Shell
appearance |
Approximates
usual shape; generally clean,* unbroken; ridges/rough spots
that do not affect the shell strength are permitted. |
Abnormal shape;
some slight stained areas permitted; unbroken; pronounced
ridges/ thin spots permitted. |
|
Usage |
Ideal
for any use, but are especially desirable for poaching,
frying and cooking in shell. |
Ideal
for any use, but are especially desirable for poaching, frying
and cooking in shell. |
Good
for scrambling, baking and as an ingredient in other foods. |
*An egg may be considered clean if
it has only very small specks, stains or cage marks.
Source: U.S.
Department of Agriculture
What to do
The average response to a
dietary increase of 100 mg/day of cholesterol is a 2.5 mg/dL change in
plasma cholesterol levels. This is an average response, and it must be
remembered that 15% to 20% of the population is more sensitive to the
effects of dietary cholesterol. For this group, dietary restriction
may make sense.
For example, in
cholesterol-sensitive people, reducing dietary cholesterol intake from
400 to 300 mg/day could result in a 3.2 mg/dL reduction in plasma
cholesterol. By comparison, cholesterol-insensitive individuals who
make the same change in their diet will have only a 1.6 mg/dL decrease
in cholesterol.
Regardless of how you
decide to use eggs in your diet, remember that good food handling
techniques are important to follow. This will ensure that you get the
benefits of eggs without adverse effects.
John
Russo Jr. is senior vice president of medical communications
at Vicus.com. He is a pharmacist and medical writer with more than 20
years experience in medical education.
This article was
updated on 3 Aug. 2000.
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