Science changes as knowledge grows and medical recommendations are growing and changing too. Yesterday’s medical guidelines may become outdated as new research comes to light or old research is reviewed. A perfect example is the egg. Eggs are an excellent and low cost source of protein, a rich source of folate and other B vitamins and contain unsaturated fats (which have been shown to reduce heart disease). However, they also contain cholesterol. For this reason, over the past 40 years, individuals have been counseled to lower their intake of eggs. It has been assumed that because eggs contain cholesterol they must also play a significant role in raising blood levels of cholesterol and thereby increase the risk of heart disease, stroke and death. After decades of study, the impacts of food cholesterol intake on blood cholesterol levels remains unclear. In this time of increasing food prices and concerns about meat production (cruel practices, hormone and antibiotic exposures), incorporating moderate amounts of eggs into a healthy diet and lifestyle may be beneficial to overall health. Here are the facts.
Studies of large groups and their egg eating habits
Large epidemiological studies (Hu and Djousse) (where a group of people are followed over a long period of time) have shown that in healthy individuals, egg consumption at a level of 6 eggs per week does not increase risk of stroke, heart attack or death. These studies have suggested that for diabetics, there may be a slight increased risk of stroke or heart disease (over the long term) with higher levels of egg consumption. Although it should be noted that these studies were not designed to be able to give a clear answer on this question. The information that was clearly gathered in this large group study said that six eggs each week did not increase risk of strokes, heart attack or death.
Studies of individuals eating eggs
Keeping this in mind, in a study of overweight men where more than 50% of the participants had metabolic syndrome (a condition that is often an early stage leading to diabetes) were placed on low carbohydrate diets and divided into two groups: one group received 3 eggs per day for 12 weeks in addition to their low carb diet, the other group received an egg substitute. At the end of the study, all individuals had lost weight, there was no change in total cholesterol in the 2 groups and the the HDL (good) cholesterol level had actually increased in the egg group. Also, only 10% of the group still had metabolic syndrome and they were in the non-egg eating group. So in 3 months of regular high level egg consumption (3 eggs per day), the entire treatment group was able to improve their cholesterol numbers and reverse their metabolic syndrome.
What about eggs for people that already have high cholesterol? In another research study, individuals with high cholesterol who were taking cholesterol medication were enrolled in a 12 week study and were advised to eat 3 eggs per day. At the end, their HDL (good) cholesterol increased and their bad cholesterol remained unchanged. Thus, eggs only had a good or no effect on the patient’s cholesterol numbers.
So, what are we to make of the evidence? Eat some eggs (but hold the bacon)
Based on well-performed, large scale trials, egg consumption on the order of ~ 1 egg/day or less appears safe with no impacts on cardiovascular disease or mortality. Levels of significantly more than one egg per day are likely safe in individuals who do not have diabetes. In diabetics, there may be some increased risk of disease at intakes of 1 egg per day or greater, but as always we need to look at the overall picture. Eating a daily egg in the context of a unhealthy diet is not going to be beneficial. However, for individuals who are adding eggs as part of an overall eating plan that lowers the amount of saturated fats (the type found in red meat, other animal fats, etc.) and increases physical activity there is likely to be benefit.
Remember also that the quality of eggs matter. I recommend buying the best eggs that you can afford. Free range and organic are the best bet, especially in light of recent food safety and animal cruelty issues with factory farmed eggs. Now that you understand the research behind eggs and that in moderate amounts they do not appear to increase bad cholesterol or cardiovascular disease risk, it is time to rethink eggs. Think about eggs for breakfast and also about incorporating them at other times of day: as healthy mid-morning snack or an omelet with veggies for an affordable, low cost, protein-rich dinner.
Late breaking news… Much was made in the media in late August 2012 about a study that supposedly showed that eating eggs was almost as bad for you as smoking.
However, closer examination shows that this study has some serious shortcomings. This was not a study of healthy individuals but rather a study of individuals who had recently had a stroke or were at high risk for a stroke. Individuals were asked to recall how many eggs they ate on average over one week. However, no other sources of dietary fat or cholesterol were assessed (meaning the high egg eaters might have been eating a side of bacon or steak with all of those eggs). In addition, it was assumed that the number of eggs that individuals reported consuming on average remained stable over many decades. Finally, the outcome that was assessed was whether there was (on average) a thicker buildup of plaque (fatty deposits) in the neck arteries of individuals who reported consuming more eggs. What researchers found was that there was an increase in this plaque size in the arteries of individuals who reported consuming the most eggs compared to those who consumed the least. However, the number of people in the study who actually reported eating more than 5 eggs per week was quite small, making it difficult to get an accurate estimate of the relationship between egg intake and plaque build up in the high egg consuming group. However, most importantly it is not clear that having a slightly thicker buildup of plaque in the arteries translates into an increased likelihood of stroke or heart attack etc. And as we have already mentioned, studies that looked at these more meaningful outcomes (e.g. whether people who eat more eggs have more strokes, heart attacks or deaths) have not found that at consumption levels of ~ an egg per day that the risk of disease increases. In summary, this recent and well publicized study does not change my recommendations as noted above.
The information contained herein should not be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a healthcare provider if you suspect you are ill.