Eggs linked to higher cholesterol and risk of heart disease

Before you tuck into your next three-egg omelette or frittata, read this.

fried bacon and eggs in iron skillet shot with selective focus

Before you tuck into your next three-egg omelette or frittata, read this.

Eggs may not be so good for you after all, according to a large new study published Friday that links higher consumption of dietary cholesterol with cardiovascular disease and death.

The findings are likely to feed into a long-running debate over whether eggs are harmful or beneficial to health, as they become increasingly trendy and US consumption grows.

Eating 300 milligrams of dietary cholesterol a day was associated with a 17 per cent higher risk of developing cardiovascular disease and an 18 per cent higher risk of death from any cause, researchers determined from analyses of the eating and health patterns of a diverse population of 29,615 US adults over several years.

Eating three to four eggs a week was linked with a 6 per cent higher risk of developing cardiovascular disease and an 8 per cent higher risk of dying from any cause, according to the study, which was led by researchers at the Northwestern University Feinberg School of Medicine and published in the Journal of the American Medical Association.

Dietary cholesterol was the driving factor behind the increased risk, rather than saturated fat or other ingredients, the researchers determined through detailed analyses. One large egg has 186 mg of dietary cholesterol in the yolk. Other sources are red meat and processed meat such as bacon.

The research was more extensive than previous work, experts said, analysing data from participants in six large cardiovascular studies and accounting for the effects of saturated fat and other factors that could affect heart health.

“This is the most comprehensive study we have to date,” said Alice Lichtenstein, a professor of nutrition science and policy at Tufts University and vice chair of the advisory committee for the current US government dietary guidelines, who wasn’t involved in the study. “The authors meticulously accounted for multiple potentially confounding factors.” The findings suggest that current US dietary guidelines may need to be revisited, the authors said. The most recent guidelines abandoned a limit on dietary cholesterol but said people should keep their consumption low. Before 2015, they recommended eating less than 300 milligrams of dietary cholesterol per day.

“I think this study will weigh heavily on the side of demonstrating there is a harmful effect of dietary cholesterol intake, and maybe shift the balance of what we know,” said Norrina Allen, associate professor of preventive medicine at Northwestern Medicine and senior author of the study.

But the study was observational, showing that people who eat lots of eggs have greater health risks but not a cause and effect. More research is needed, the authors said.

The findings “are interesting and point to the need for further research, ” said Mickey Rubin, executive director of the American Egg Board’s Egg Nutrition Center. The study conflicts with previous work, he said. “This study is inconsistent with multiple recent studies showing no association between eggs and heart disease risk.” The risk from eating three to four eggs a week was modest, Robert Eckel, professor of medicine in endocrinology and cardiology at the University of Colorado School of Medicine, wrote in an editorial accompanying the study. But the risk increased the more cholesterol people consumed, he noted. Those who ate two eggs a day had a 27 per cent higher risk of cardiovascular disease and a 34 per cent higher risk of death, he wrote.

The dietary information came from a questionnaire that participants filled out when they joined one of the cardiovascular cohorts. The researchers then analysed data collected on them, following them for a median of 17.5 years.

The associations between dietary cholesterol consumption and cardiovascular disease were stronger in people whose LDL, or “bad” cholesterol, was above 70 milligrams per decilitre, or whose non-HDL cholesterol was above 100 mg/dL. Dr Allen said. Non-HDL is total cholesterol minus HDL, or “good” cholesterol. The link between dietary cholesterol and mortality was stronger in women than in men, the study said.

People shouldn’t avoid eggs altogether, Dr Allen said. “There are potentially beneficial parts of an egg,” she said, such as choline, an essential nutrient, and amino acids which are important for good health. “It’s all about moderation.”

The Wall Street Journal