Are eggs good for health or not?
Researchers have long argued about how eggs affect human health. Now scientists have concluded that whole eggs are good for young people.Instead of looking at how egg consumption affects specific body systems and diseases, the authors of the new study took a broader approach. They found that, in general, eating whole eggs improves the health of young people.
In most previous studies, scientists have looked at the effects of eggs on specific biomarkers of cardiovascular disease, diabetes, body composition, inflammation, immune health and anemia, rather than the body as a whole. University of Connecticut (UConn) researchers looked at the whole situation.
The researchers recruited 28 healthy participants between the ages of 18 and 35 and fed them one of three diets for four weeks: no eggs, three egg whites a day, or three whole eggs a day. After the four-week egg-free period, the egg-eating participants switched to an alternative diet. The eggs could be cooked the way the participants preferred. The researchers then examined the effects of the different egg diets on the participants' metabolic, immune, and hematologic profiles.
They found that blood samples from people who ate whole eggs had significantly increased levels of choline, an important nutrient found in yolks. The brain and nervous system use it to regulate memory, mood, muscle control and other bodily functions. Metabolizing choline leads to the formation of trimethylamine N-oxide (TMAO), and scientists have previously linked TMAO to heart disease. However, the researchers noticed that TMAO did not change in participants who ate whole eggs.
The researchers also saw no adverse changes in inflammation or blood cholesterol levels. Egg white consumption increased serum isoleucine levels, a marker of increased risk for insulin resistance. Whole egg consumption, on the other hand, lowers serum glycine levels, a marker of decreased risk of insulin resistance. Whole egg consumption increased hematocrit (a measure of the proportion of red blood cells in the blood that decreases in anemia), while egg whites and whole eggs lowered the number of platelets in the blood.
Results from female participants who were taking combined oral contraceptives (COCs) differed. There was a greater increase in the ratio of total cholesterol to HDL-cholesterol (considered "good" cholesterol), which is considered a risk factor for cardiovascular disease, in blood samples from women who were not on the pill. Also, women who did not take the pill had higher levels of monocytes in their blood compared to those who took OCs. Monocytes are a type of white blood cells (white blood cells) that destroy viruses, bacteria, fungi and other pathogens that threaten health.
The study is published in the journal Nutrients.