It's no yolk: Americans for decades have gotten dietary whiplash from the back-and-forth science on whether eggs are good for them.
But a major new study will have many egg-lovers relieved: You can enjoy an egg a day without having to worry about your heart.
No funding from egg industry
"Moderate egg intake, which is about one egg per day in most people, does not increase the risk of cardiovascular disease or mortality even if people have a history of cardiovascular disease or diabetes," said study lead author Mahshid Dehghan. She's an investigator at the Population Health Research Institute (PHRI) of McMaster University in Hamilton, Canada.
The study, which analysed data on more than 177 000 people, was funded by various provincial government health agencies in Ontario, and non-profit groups focused on heart health. It received no funding from the egg industry.
Dehghan's group pored over data from three large, long-term international studies, all conducted at the PHRI. The three studies involved people with various income levels living in 50 countries on six continents, so the results are widely applicable, the researchers said.
Most of the people in the studies had one or fewer eggs a day, suggesting that this level of consumption is safe, Dehghan said.
"Also, no association was found between egg intake and blood cholesterol, its components or other risk factors," she said in a McMaster news release. "These results are robust and widely applicable to both healthy individuals and those with vascular disease."
Give eggs a break
Eggs are an inexpensive source of essential nutrients, but some nutritional guidelines have advised that people should limit intake to fewer than three eggs a week, due to concerns they increase the risk of heart disease. But as study principal investigator Salim Yusuf pointed out, prior studies about eggs and health have yielded conflicting findings.
"This is because most of these studies were relatively small or moderate in size and did not include individuals from a large number of countries," Yusuf said in the news release. He directs the PHRI.
Two US experts in nutrition and heart health agreed that maybe it's time – again – to give eggs a break.
"The case of eggs causing heart disease has been cracked – Humpty Dumpty can remain on the wall," said Dr Guy Mintz, who directs cardiovascular health at the Sandra Atlas Bass Heart Hospital in Manhasset, New York. "This very large study has clearly demonstrated that people can have one egg a day without any cardiovascular consequences."
Mintz believes eggs are a good source of many nutrients, and he stressed that no deleterious effect was seen, even in people who already had heart disease or were taking medications.
Audrey Koltun is a registered dietitian in the division of paediatric endocrinology at Cohen Children's Medical Center in Lake Success, New York. She said, "I am so happy to hear that eggs are not the bad guys anymore."
Nutritious in other ways
The nutritional value of eggs is a constant question from her clients, Koltun said, and "the answer has always been complicated because previous research on this topic has been conflicting."
Eggs do have high cholesterol levels, she said, but they are also very nutritious in other ways.
"They have many essential vitamins and minerals as well as they contain very high-quality protein," Koltun said. "The egg white contains most of the protein; the yolk contains iron, phosphorus, fat-soluble vitamins including vitamin D, B vitamins, healthy fat, and other valuable nutrients."
Besides all that, eggs are "inexpensive, are not processed or have added sugars or added food dyes, preservatives, artificial flavours," she noted. "Now with science backing me up, I can now answer the question about eggs."
The study was published recently in the American Journal of Clinical Nutrition.
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