As sure as eggs is eggs, every day brings a new study that seems to contradict previous dietary advice. Thankfully our expert dietitian Sarah Noone,  is on hand to descramble the evidence.

Recently a US study suggested that people who have a higher intake of eggs could be at a higher risk of heart disease and early death because of the high level of dietary cholesterol in eggs. This is not the first time that the role of eggs in relation to cholesterol and heart disease has hit the headlines and caused confusion. So, let’s examine the science.

Here is the science bit
There are several limitations to this study including the fact that it was observational and therefore could only show an association, rather than cause and effect e.g. it only shows a relationship but doesn’t prove anything.

Additionally, the study was based on food recall or people’s memory of what they had eaten. When it comes to nutrition research the fact is that most of us cannot accurately recall what we have eaten, this is known as recall bias. For example, can you remember everything you ate this month or even this week? Even if people had accurately recalled what they had eaten, there are so many other confounding factors which could have an impact on a person’s risk of heart disease that it is difficult to identify how one food or component of a person’s diet could affect their risk.
Also, the researchers did not look at the rest of the participants’ diets. They only asked about egg consumption e.g. were those who were consuming more eggs also eating more processed meats such as bacon or sausages? We don’t know this because they didn’t track it.

This means that other lifestyle or dietary factors may be responsible for the increased risk of heart disease found by the study. Therefore, to draw any firm causative conclusions from this type of data is impossible.

This study highlights the importance of ensuring that the media are careful not to sensationalise every contradictory finding when it comes to observational studies that focus on one single nutrient or food. Of course, these studies are important in adding to the body of current evidence, but they need to be put into context with regards the entirety of the evidence.

Balance
Eating healthily is all about balance. If you’re eating too much of one thing it leaves less room in the diet for other foods that may have more health benefits. In the past, it was thought that we needed to limit the number of eggs we ate due to the presence of dietary cholesterol and its effect on our cholesterol levels. However, this confusion may have been down to the fact that foods higher in dietary cholesterol are often also high in saturated fat (except eggs and prawns).

The entirety of the current research shows that for most healthy people, dietary cholesterol in food, such as eggs, has a relatively minimal effect on cholesterol levels, and it is the saturated fat in foods such as butter, red/processed meats, fried foods, cakes and crisps etc. that increases cholesterol levels. Therefore, it is more important to eat less of these foods high in saturated fat for out heart health.

Bottom Line:
The general healthy population can enjoy moderate egg consumption as part of a balanced diet. Individuals, with a diagnosis of genetically high cholesterol however would still be advised to restrict dietary cholesterol intake and should discuss this with their GP or dietitian who knows their medical history. Eggs are a nutritious food, but you still need to need to pay attention to how they are cooked and the ‘trimmings’ that come with them.