Archive for January, 2013

The most athletes know that protein is critical in the muscle-building process. Every tissue in the human body consists of proteins that are constantly being broken down and need to be replaced in the body. Eggs are one of the best sources of protein for strength and conditioning athletes; they contain all of the amino acids an athlete needs to gain size and strength. In fact, the protein from eggs is even used in some types of protein powders lately. But let’s find out everything about eggs, from both a health and a performance perspective.

Capture

The truth with cholesterol (Science VS History):

It’s true that when you compare egg yolks to other foods they are relatively high in cholesterol, as the average egg contains anywhere between 190 and 215 milligrams. Cholesterol is something that many people should be concerned about, but not so much in the case of eggs. Studies have shown that regularly eating eggs can actually lower your low density lipids (that’s “bad” cholesterol) and raises high density lipids. The dangers of a high cholesterol diet may also have been exaggerated in the media as some studies have proven that people who maintain a low cholesterol diet still may have elevated cholesterol levels. This is because cholesterol actually serves several important functions in the body, and when you don’t get enough, it makes its own. In fact the liver produces about the two thirds of the body’s cholesterol, with dietary intake having very little impact on the overall levels. Limiting dietary cholesterol intake is important but the real danger comes from other risk factors, such as saturated and trans fat in addition to a sedentary lifestyle, overeating and smoking, as research suggests (1). These are greater factors in increasing cholesterol and causing heart related problems than any typical intake of egg yolks. It doesn’t make much sense to separate egg yolks to avoid the cholesterol while eating deep fried fatty foods, pizza and other junk in a normal western diet.

The benefits:

An average egg weighs about 60 grams and is composed by 11% of the shell, 58% of the egg white and 31% by yolk (2). The egg white consists primarily of water (88%) and proteins (9%), and the yolk consists of water (51%), lipids (31%) and protein (16%) (2). According to the U.S. Department of Agriculture’s nutrient database, each egg contains 6.28 grams of protein, 72 calories, 4.75 grams of total fat, and small amounts of vitamins and minerals. The key nutrients found in eggs, such as vitamin D, vitamin B12, folic acid and selenium have been associated with the prevention of chronic conditions such as heart disease, high blood pressure, impaired cognitive function and congenital anomalies. A UK study has found that adults who consumed three or more eggs per week had significantly higher intakes of vitamin B12, A and D, niacin (B3), iodine, zinc and magnesium, compared with those that were not consuming eggs (3). The relatively high content of eggs in vitamin D is remarkable, since few foods are recognized as good sources of this vitamin. Overall, the nutritional composition of eggs can be changed via the feed given to hens. This is the case, for example, eggs with high content of docosahexaenoic acid (DHA), an omega-3 fatty acid important for brain development, normal vision, heart health and certain other physical functions (4). Moreover, these fats are desirable because they help in controling hormone regulation and cellular growth in the body.

Thus, YES, eggs are indeed wonderful for your body and brain. The harmful effects of eggs have been completely overblown (5). But there is also another story to eggs. For instance, scientists have known that reduced brain serotonin function is involved in stress-related disturbances and may occur under conditions of chronic stress. We also know that serotonin production depends on the availability of tryptophan (TRP). Recently, an egg protein hydrolysate (EPH) was developed that showed a much greater effect on brain TRP availability than pure TRP and other TRP-food sources.

How to cook eggs?
Hheating the egg does cause indeed some chemical changes that damage some of the nutritional profile of the egg, but not too much to be concerned about. If you are considering eating raw eggs, then although raw eggs are very easy on the digestive system, it is very common to experience some stomach discomfort when starting a new raw egg regimen. For this reason i would recommend to enjoy your eggs cooked!

Recommendations:

So far so good with the egg quality, composition and health benefits. Let’s talk about recommendations. Here comes the question “how many eggs per day?”. As we already mentioned, saturated and trans fat may actually be a larger contributor than eggs to cholesterol levels. A single egg contains a gram or two of saturated fat, so eggs are fine in moderate amounts, but you should avoid eating too many eggs because of possible consequences to the cardiovascular system. Generally this is not a problem. You would have to eat more than 10 eggs a day to consume too much saturated fat. However, you may want to monitor your egg consumption if you are also eating bacon, red meat, butter and other foods high in saturated fat. Also, as a nutritionist i would not answer this question with a specific number. It’s like with fruits. I can not recommend a specific amount for everyone without knowing the diet (other sources from cholesterol when recommending for egg consumption), the lifestyle, the goals and the exercise training each follows. However, just for the record, the UK Food Standards Agency no longer places a limit on the number of eggs that you should eat ;)

References:

1) Barraj et al. (2009). A comparison of egg consumption with other modifiable coronary heart disease lifestyle risk factors: A relative risk apportionment study. Health Sciences practice. 29(3):401-15
2) Food Standards Agency (2002). McCance and Widdowsonsâ??s The Composition of Foods, 6th summary edition. Cambridge: Royal Society of Chemistry.
3) Ruxton CHS et al. (2010). Nutritional and health benefits of consuming eggs. Nutrition & Food Science 40:263-279.
4) European Food Safety Authority (2010).
5) Egg-cellent news for most, but not those with diabetes. The harmful effects of eggs were overblown, but the studies show that people with diabetes should still limit how many they eat. Harv Health Lett. Jul (2008) ;33(9):6.
6) Nakamura Y, Iso H, Kita Y, et al. Egg consumption, serum total cholesterol concentrations and coronary heart disease incidence: Japan Public Health Center-based prospective study. Br J Nutr. Nov (2006) ;96(5):921-928.