Cholesterol is a fatty substance which is vital for bodily function, but having too much can cause the arteries to narrow and increase the risk of heart attack and stroke. A study of nearly 30,000 adults found those who ate more than 300mg of cholesterol – the amount in two eggs – per day had a 17 per cent higher risk of heart disease and an 18 per cent raised risk of dying. Eating three to four eggs per week was also linked with a six per cent higher risk of cardiovascular disease and eight per cent higher risk of any cause of death. Researchers at Northwestern University in the United States said public health guidelines may need to include weekly limits on egg and dietary cholesterol consumption.
There is no recommended limit on how many eggs people should eat, according to the NHS.
The British Heart Foundation says 420 people die from cardiovascular disease in the UK every day.
Co-corresponding study author Dr Norrina Allen, associate professor of preventative medicine at Northwestern University Feinberg School of Medicine, said: “The take-home message is really about cholesterol, which happens to be high in eggs and specifically yolks.
“As part of a healthy diet, people need to consume lower amounts of cholesterol. People who consume less cholesterol have a lower risk of heart disease.”
The study also found that cholesterol was the driving factor independent of saturated fat consumption and other dietary fat.
Lead author Dr Wenze Zhong, a postdoctoral fellow in preventative medicine at Northwestern, said people should keep dietary cholesterol intake low by reducing cholesterol-rich foods such as eggs and red meat in their diet.
He said egg yolks are one of the richest sources of dietary cholesterol among all commonly consumed foods.
One large egg has 186mgs of dietary cholesterol in the yolk but other animal products such as red meat, processed meat and high-fat dairy products – butter or whipped cream – also have high cholesterol content.
Dr Zhong said people should not stop eating eggs and meats as they are good sources of important nutrients such as essential amino acids, iron and choline.
He recommended consuming egg whites instead or eating whole eggs in moderation.
Dr Allen added: “We want to remind people there is cholesterol in eggs, specifically yolks, and this has a harmful effect.
“Eat them in moderation.”
The study findings contradict previous studies that found eating eggs or dietary cholesterol had no effect on the risk of cardiovascular disease.
This contributed to US guidelines dropping a 300mg recommended daily cap on cholesterol in 2015.
The new study, published in the Journal of the American Medical Association (JAMA), looked at pooled data on 29,615 US racially and ethnically diverse adults from six prospective cohort studies for up to 31 years of follow up.
She said: “Our study showed if two people had exact same diet and the only difference in diet was eggs, then you could directly measure the effect of the egg consumption on heart disease.
“We found cholesterol, regardless of the source, was associated with an increased risk of heart disease.”
She added the study findings mean the current US dietary guideline recommendations for dietary cholesterol and eggs may need to be re-evaluated.