Every-time I crack a raw egg into my protein shake or swallow one raw my wife has to make a wise crack about Rocky and his 5 raw egg breakfast.
Consumption of raw eggs has garnered long-standing controversy from; you’ll hear everything from eating a raw egg will cause almost certain death to the only way to unlock an eggs full potential is by eating it raw. The truth, as always, is somewhere in-between.
Cooking Eggs Ruins the Protein, Right?
Lets go ahead and dispel this myth. Cooking does not ruin the protein in an egg. Actually, if you look at the following data, courtesy of nutritiondata, the protein quality ratings (the higher the number, the higher the protein quality) for raw eggs and eggs cooked in a variety of methods might surprise you.
- Raw eggs: Protein Quality = 136
- Fried eggs: Protein Quality = 136
- Poached eggs: Protein Quality = 137
- Scrambled eggs: Protein Quality = 132
- Hardboiled eggs: Protein Quality = 132
So while there is some truth to the statement that cooking ruins the protein in an egg, it really comes down to how they are cooked. Poaching actually improves the protein quality when compared to a raw egg. A fried egg has the same quality as a raw egg. Hard-boiling and scrambling lowers protein quality due to longer cooking times. But the real underlying truth here is that regardless of cooking method the protein quality of an egg is not significantly altered.
Eating raw eggs also carries the eventual risk of a biotin deficiency. Although egg yolk is actually a rich source of biotin, the white contains avidin, a glycoprotein that bonds with biotin, preventing the nutrient’s absorption. Avidin is generally inactivated when cooked, which makes the biotin in the yolk fully available for absorption by the body.
Possible Benefits of Eating Raw Eggs
The number one benefit of eating raw eggs is ease of consumption. When pressed for time the last thing I want to do is fry up some eggs, and in the early morning the last thing I want to do is shovel six eggs down my throat. Cracking a some eggs into a glass and chugging away or mixing a couple into a protein shake for a little thickness takes seconds. It might qualify as lazy, but there’s a reason some of us do it. If eating a raw egg is what gets you to eat an egg versus a doughnut, the risks outlined below might just be worth it.
Like most foods, eggs undergo some loss of nutrients when they are cooked. If you compare the nutrient value of one large raw egg to one large hard-boiled egg at the U.S. Department of Agriculture’s nutritional database, you will find the following potential advantages offered by eating a raw egg:
- 36% more vitamin D
- 33% more omega-3s
- 33% more DHA
- 30% more lutein + zeaxanthin
- 23% more choline
- 20% more biotin
- 19% more zinc
Now before you get too excited about these numbers, for some of these nutrients, the greater percentage in a raw egg may not make for a practical difference. For example, even though the amount of vitamin D in a raw egg drops from 41 IU to 26.5 IU during hard boiling, a raw egg only provides 10% of the Daily Value (DV) for vitamin D to begin with. Whether you are getting 10% of the DV from a raw egg or 7% from a hard-boiled egg, you clearly don’t want to rely on eggs for your vitamin D.
The Drawbacks Associated with Raw Eggs
Contamination is the highest risk, and particularly by Salmonella enteritidis (SE). Many types of bacteria are naturally present not only on the shell of an egg but also inside the shell. These types of bacteria often include Campylobacter, Enterococcus, Listeria, and Salmonella. When hens are healthy, these bacteria have populations that stay in balance and do not pose a danger to the hens. However, these same-sized populations of bacteria might pose a health risk to us.
Since the 1970’s, the total number of annual Salmonella infection cases among children and adults in the U.S. has varied from about 140,000 to 300,000. This relatively large number of cases is due to the large number of eggs produced and consumed in the U.S. The average U.S. adult consumes about five eggs per week. About 762 billion eggs are produced in the U.S. each year, and nearly 30% of these eggs (228 billion) are processed at “breaker plants” into egg products.
Estimates of Salmonella contamination in eggs range from 1 out of every 20,000 eggs to 1 out of every 30,000 eggs. On an individual basis, a person who eats 1 egg per day would expect to consume 1 contaminated egg every 54 years. If you’re like me you have your own backyard chickens safety is even less of a concern, I can watch for health issues with my birds and make sure they’re eating well. But even with eggs from the grocery store the risk is relatively low.
Can You Determine a Bad Egg by Appearance and Smell?
It is possible to detect some aspects of egg safety from visual inspection of an egg and evaluation of its odor. Here are some things you can look for:
- Cloudiness of egg whites: The white of a fresh egg is naturally cloudy. This cloudiness is mostly due to the presence of dissolved carbon dioxide and the suspension of albumen proteins in the watery liquid that forms the white. As an egg ages, carbon dioxide will escape through pores in the shell and the white will may also become less acidic. You can generally use the cloudiness of the egg white to help confirm freshness, not contamination. But it is still helpful, the fresher the egg, the lest likely any contaminating bacteria would have had the chance to replicate to dangerous levels.
- Yolk firmness and color: Yolk color is mostly related to the hen’s diet. If the hen eats more pigmented plants (for example, the petals of flowers with orange or yellow pigments or yellow corn), the yolk will typically be darker and richer in color. By contrast, if the hen eats large amounts of white corn in her feed, the yolk will be less colorful. The yolk will also undergo changes as it ages. Over time, the yolk membrane will weaken, and the yolk will become flatter.
- Red blood spots on the yolk: These spots are caused by the breaking of a blood vessel along the surface of the yolk. This type of breakage can occur naturally and is not a sign of contamination.
- Pinkish egg whites: If the egg white has a pinkish color, it is usually a sign of bacterial spoilage, most often it is Pseudomonas.
- Off odors: Many different types of spoilage bacteria will produce off-odors in eggs. These off odors may be sulfur-like, or they might simply just smell “bad.”
Most visible characteristics of an egg are related to freshness, the breed of the hen and her genetics, and her diet. While freshness might help you avoid a contaminated egg, there is not surefire way to be sure. A perfectly normal looking and smelling egg could be harboring Salmonella in levels adequate to make you very sick.
Raw Eggs and Egg Allergies
Eggs are one of the most common allergy-related foods in the U.S. diet, and approximately 1-2% of all U.S. children develop egg allergy. Typically the allergy is to either ovalbumin (OVA) or ovomucin (OVM). Both OVA and OVM are proteins naturally found in the white of all hen’s eggs.
Recent research studies have shown that OVA and OVM are made more digestible through cooking, as well as less likely to get transported out of the digestive tract and up into the bloodstream. For this reason, cooked eggs are associated with less allergic response than raw eggs.