Almost everywhere on earth, eggs are the universal symbol for a good breakfast. Eaten across the planet, for as long as we’ve known that one of our favourite foods also poos out another kind of food, cooks have been happily scrambling, boiling and frying their way to eggy glory. Whichever way you spin it, it’s undeniable that the world loves a good egg.
The question over the relative impact of egg eating has been bothering scientists for years. Over the past decade, it looked as though everyone had concluded that eggs are basically a good thing. However, even though they’ve cured a billion hangovers and inspired anyone confronted with a barren fridge, new research suggests that eggs may not be as innocent as we’ve been led to believe. With the publication of some dramatic new research, it looks as though we may be forced to reassess how we feel about our gooey, oviform alarm clocks.
According to a paper published by the JAMA medical journal, there is strong evidence that eating more than one or two eggs a week could have serious repercussions for cardiovascular health. The study states that people who eat three or four eggs per week have “a higher risk of both heart disease and early death compared with those who eat fewer eggs,” according to reporting by CNN.
The key to this new development is cholesterol. While some cholesterol is an integral part of a healthy human diet, researchers found that ingesting around 300 milligrams more dietary cholesterol than is recommended run a dramatically increased risk of suffering a heart attack. For context, this amount of cholesterol can be found in about two large eggs. The JAMA study therefore concluded that eating too many eggs can elevate the risk of serious cardiovascular complications.
"Eggs, specially the yolk, are a major source of dietary cholesterol," wrote study lead Victor Zhong in his summary. This lead him to conclude that they do indeed play a significant role in impacting our overall cardiovascular health. Zhong and his team spent months examining data from six separate US study groups of more than 29,000 people, collating results from across a 17 year period. The team identified a total of 5,400 cardiovascular events, including 1,302 fatal and nonfatal strokes, 1,897 incidents of fatal and nonfatal heart failure and 113 other heart disease deaths.
Zhong argues that the reason we have never been able to agree over whether eggs were doing more harm than good was the failure of other studies to take into account the fact that “egg consumption may be related to other unhealthy behaviors, such as low physical activity, smoking and an unhealthy diet (sic).” Zhong’s study, by contrast, “included (a) comprehensive assessment of these factors."
Despite the compelling evidence of the JAMA piece, some scientists are still urging caution before we throw out all our egg cartons. Speaking to Science Media Centre after the research was published, senior dietitian Victoria Taylor revealed that "this type of study can only show an association, rather than cause and effect, and more research is needed for us to understand the reasons behind this link." She went on to add that, "Eggs are a nutritious food and, while this study focuses on the amount we're eating, it's just as important to pay attention to how the eggs are cooked and to the trimmings that come with them." Sensible though this advice seems, it’s impossible not to feel a little more suspicious now that Zhong’s work is out in the open.