HANGZHOU, China — The link between eggs and health has been hotly debated for years. While some believe eggs can be part of a healthy diet, others warn all that cholesterol can be bad for the heart. A new study finds both arguments might be right. Researchers in China say while egg whites can be healthy, adding the cholesterol from just two whole eggs to your diet each day can significantly increase your risk of death.
A team from Zhejiang University finds the yolks of eggs are high in cholesterol and fat, which can fuel heart attacks, strokes, and cancer. They warn that people should use only the whites or switch to healthier egg substitutes.
Their findings suggest that those who consume an additional 300 milligrams of cholesterol a day, less than two eggs, are 19 percent more likely to die prematurely. The risk of dying from cardiovascular disease (CVD) and cancer jumped by 16 and 24 percent, respectively. The average whole egg contains about 186 mg of cholesterol.
“In this study, intakes of eggs and cholesterol were associated with higher all-cause, CVD, and cancer mortality,” researchers Yu Zhang, Jingjing Jiao, and their team write in the journal PLOS Medicine. “The increased mortality associated with egg consumption was largely influenced by cholesterol intake.”
Study authors find for every additional half of a whole egg consumed each day, the risk of death goes up by another seven percent.
Dietary guidelines need a do-over
Although many countries, including the United States, include eggs in their national dietary guidelines, researchers say eaters should be avoiding the yolk. This is where the bulk of the harmful cholesterol is coming from.
“Our findings suggest limiting cholesterol intake and replacing whole eggs with egg whites/substitutes or other alternative protein sources for facilitating cardiovascular health and long-term survival,” study authors report.
“The current recommendations for egg and dietary cholesterol intake from the U.S. dietary guidelines might lead to increases in cholesterol intake, which could be detrimental to the prevention of premature death. Clinicians and policy makers should continue to highlight limiting cholesterol intake in the U.S. dietary recommendations, considering our results.”
What makes eggs so bad?
Cholesterol can build up in the arteries leading to a clot. This can block off blood supply to the blood and brain. What is less well known is when someone eats eggs, a toxic compound called TMAO (trimethylamine oxide) is released into the blood stream by gut bacteria.
Recent research suggests the chemical can promote the growth of tumors in the bowel, bladder, prostate gland, breast, or ovaries. It also makes the digestive tract especially vulnerable.
The latest analysis, based on a food survey of more than half a million Americans between 50 and 71 years-old, is the biggest of its kind. To this point, data from large-scale studies on egg consumption has been scarce.
While whole eggs may be particularly harmful, the study finds egg whites or egg substitutes reduce mortality rates noticeably too. For those eating only egg whites, death rates from CVD, cancer, and respiratory disease declined by three, eight, and 20 percent, respectively.
Substituting an equivalent amount of nuts or legumes for half a whole egg reduced death rates by up to a third. Poultry, fish, or dairy products had a similar effect. Researchers examined 129,328 deaths among 521,120 participants during the study which began in 1995 and followed the group until 2011.
Time to change the ‘Western’ diet?
Numerous studies have revealed a connection between plant-based diets and a decreased risk of heart disease. A vegan diet has been found to be more effective at preventing heart disease than the American Heart Association-recommended diet of small amounts of fish, lean meats, and eggs.
Prof. Zhang’s team says the findings remained steady after accounting for other dietary factors such as age, sex, and education. It also did not matter if participants consumed fried, boiled, poached, or baked eggs.
“Our results should be considered by clinicians and policy makers in updating dietary guidelines for Americans,” study authors conclude.
SWNS writer Mark Waghorn contributed to this report.