Eggs

More than half the calories found in eggs come from the fat in the yolk; a large (50 gram) chicken egg contains approximately 5 grams of fat. People on a low-cholesterol diet may need to reduce egg consumption; however, only 27% of the fat in egg is <a href="http://en.wikipedia.org/wiki/Saturated_fat" title="Saturated fat" >saturated fat</a>(<a href="http://en.wikipedia.org/wiki/Palmitic_acid" title="Palmitic acid" >palmitic</a>, <a href="http://en.wikipedia.org/wiki/Stearic_acid" title="Stearic acid" >stearic</a> and <a href="http://en.wikipedia.org/wiki/Myristic_acid" title="Myristic acid" >myristic acids</a><a href="http://en.wikipedia.org/wiki/Egg_(food)#cite_note-30" >[31]</a>) that contains LDL cholesterol. The <a href="http://en.wikipedia.org/wiki/Egg_white" title="Egg white" >egg white</a> consists primarily of water (87%) and protein (13%) and contains no cholesterol and little, if any, fat.

There is debate over whether egg yolk presents a health risk. Some research suggests dietary <a href="http://en.wikipedia.org/wiki/Cholesterol" title="Cholesterol" >cholesterol</a> increases the ratio of total to<a href="http://en.wikipedia.org/wiki/High-density_lipoprotein" title="High-density lipoprotein" >HDL cholesterol</a> and, therefore, adversely affects the body's cholesterol profile;<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-31" >[32]</a> whereas other studies show that moderate consumption of eggs, up to one a day, does not appear to increase <a href="http://en.wikipedia.org/wiki/Heart_disease" title="Heart disease" class="mw-redirect" >heart disease</a> risk in healthy individuals.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-Hu-32" >[33]</a>

<a href="http://en.wikipedia.org/wiki/Harold_McGee" title="Harold McGee" >Harold McGee</a> argues that the cholesterol in the yolk is not what causes a problem, because fat (in particular, saturated) is much more likely to raise cholesterol levels than the actual consumption of cholesterol.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-McGee-2" >[3]</a> A 2007 study of nearly 10,000 adults demonstrated no correlation between moderate (six per week) egg consumption and <a href="http://en.wikipedia.org/wiki/Cardiovascular_disease" title="Cardiovascular disease" >cardiovascular disease</a> or <a href="http://en.wikipedia.org/wiki/Stroke" title="Stroke" >strokes</a>, except in the subpopulation of <a href="http://en.wikipedia.org/wiki/Diabetes" title="Diabetes" class="mw-redirect" >diabetic</a>patients who presented an increased risk of <a href="http://en.wikipedia.org/wiki/Coronary_heart_disease" title="Coronary heart disease" class="mw-redirect" >coronary heart disease</a>.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-33" >[34]</a>

Other research supports the idea that a high egg intake increases cardiovascular risk in diabetic patients.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-34" >[35]</a> A 2009 prospective cohort study of over 21,000 individuals suggests that "egg consumption up to 6/week has no major effect on the risk of <a href="http://en.wikipedia.org/wiki/Cardiovascular_disease" title="Cardiovascular disease" >CVD</a> and mortality and that consumption of 7+/week is associated with a modest increased risk of total mortality" in males, whereas among males with diabetes, "any egg consumption is associated with an increased risk of all-cause mortality and there was suggestive evidence for an increased risk of <a href="http://en.wikipedia.org/wiki/Myocardial_infarction" title="Myocardial infarction" >MI</a> and <a href="http://en.wikipedia.org/wiki/Stroke" title="Stroke" >stroke</a>".<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-35" >[36]</a>

Studies have shown conflicting results about a possible connection between egg consumption and <a href="http://en.wikipedia.org/wiki/Type_two_diabetes" title="Type two diabetes" class="mw-redirect" >type two diabetes</a>. A 2008 study by the Physicians' Health Study I (1982–2007) and the Women's Health Study (1992–2007) determined the “data suggest that high levels of egg consumption (daily) are associated with an increased risk of type 2 diabetes.”<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-36" >[37]</a> However, a study published in 2010 found no link between egg consumption and type 2 diabetes.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-37" >[38]</a>

A health issue associated with eggs is contamination by <a href="http://en.wikipedia.org/wiki/Pathogenic" title="Pathogenic" class="mw-redirect" >pathogenic</a> <a href="http://en.wikipedia.org/wiki/Bacteria" title="Bacteria" >bacteria</a>, such as <a href="http://en.wikipedia.org/wiki/Salmonella_enteritidis" title="Salmonella enteritidis" class="mw-redirect" >Salmonella enteritidis</a>.

Contamination of eggs exiting a female bird via the <a href="http://en.wikipedia.org/wiki/Cloaca" title="Cloaca" >cloaca</a> may also occur with other members of the Salmonella genus, so care must be taken to prevent the egg shell from becoming contaminated with <a href="http://en.wikipedia.org/wiki/Fecal" title="Fecal" class="mw-redirect" >fecal</a> matter.

In commercial practice, eggs are quickly washed with a sanitizing solution within minutes of being laid. The risk of infection from raw or undercooked eggs is dependent in part upon the sanitary conditions under which the hens are kept.

Health experts advise people to refrigerate eggs, use them within two weeks, cook them thoroughly, and never consume raw eggs.<a href="http://en.wikipedia.org/wiki/Egg_(food)#cite_note-cspinet-26" >[27]</a>

As with <a href="http://en.wikipedia.org/wiki/Meat" title="Meat" >meat</a>, containers and surfaces that have been used to process raw eggs should not come in contact with ready-to-eat food.

A study by the U.S. Department of Agriculture in 2002 (Risk Analysis April 2002 22(2):203-18) suggests the problem is not as prevalent as once thought. It showed that of the 69 billion eggs produced annually, only 2.3 million are contaminated with Salmonella—equivalent to just one in every 30,000 eggs—thus showing Salmonella infection is quite rarely induced by eggs.

However, this has not been the case in other countries, where Salmonella enteritidis and <a href="http://en.wikipedia.org/wiki/Salmonella_typhimurium" title="Salmonella typhimurium" class="mw-redirect" >Salmonella typhimurium</a> infections due to egg consumptions are major concerns.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-ccni-38" >[39]</a><a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-phis-39" >[40]</a><a href="http://en.wikipedia.org/wiki/Egg_(food)#cite_note-lost-40" >[41]</a>

Egg shells act as <a href="http://en.wikipedia.org/wiki/Hermetic_seal" title="Hermetic seal" >hermetic seals</a> that guard against bacteria entering, but this seal can be broken through improper handling or if laid by unhealthy chickens. Most forms of contamination enter through such weaknesses in the shell.

In the <a href="http://en.wikipedia.org/wiki/UK" title="UK" class="mw-redirect" >UK</a>, the <a href="http://en.wikipedia.org/wiki/British_Egg_Industry_Council" title="British Egg Industry Council" >British Egg Industry Council</a> award the lions stamp to eggs that, among other things, come from hens that have been vaccinated against<a href="http://en.wikipedia.org/wiki/Salmonella" title="Salmonella" >Salmonella</a>.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-41" >[42]</a><a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-42" >[43]</a><a href="http://en.wikipedia.org/wiki/Egg_(food)#cite_note-43" >[44]</a>

One of the most common <a href="http://en.wikipedia.org/wiki/Food_allergy" title="Food allergy" >food allergies</a> in infants is eggs.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-food_allergy-44" >[45]</a> Infants usually have the opportunity to grow out of this allergy during childhood, if exposure is minimized.<a href="http://en.wikipedia.org/wiki/Egg(food)#cite_note-45" >[46]</a>

<a href="http://en.wikipedia.org/wiki/Allergy" title="Allergy" >Allergic reactions</a> against egg white are more common than reactions against egg yolks.<a href="http://en.wikipedia.org/wiki/Egg_(food)#cite_note-isbn3-540-20768-6-46" >[47]</a>

In addition to true allergic reactions, some people experience a <a href="http://en.wikipedia.org/wiki/Food_intolerance" title="Food intolerance" >food intolerance</a> to egg whites.<a href="http://en.wikipedia.org/wiki/Egg_(food)#cite_note-isbn3-540-20768-6-46" >[47]</a>

Food labeling practices in most developed countries now include eggs, egg products and the processing of foods on equipment that also process foods containing eggs in a special allergen alert section of the ingredients on the labels.