New research reignites eggs-cholesterol debate
The latest American research on eggs won’t go over easy for those who can’t eat breakfast without them.
Adults who ate about 11⁄2 eggs daily had a slightly higher risk of heart disease than those who ate no eggs. The study showed that the more eggs, the greater the risk. The chances of dying early were also elevated.
The researchers say the culprit is cholesterol, found in egg yolks and other foods.
The study focused on eggs because they are among the most commonly eaten cholesterol-rich foods. They can still be part of a healthy diet, but in smaller quantities than many Americans have become used to, the researchers say.
US dietary guidelines that eased limits on cholesterol have helped eggs make a comeback.
The results were published yesterday in the Journal of the American Medical Association.
Researchers at Northwestern University’s Feinberg School of Medicine and elsewhere pooled results from six previous studies, analysing data on almost 30,000 US adults who self-reported their daily food intake. Participants were followed for roughly 17 years, on average.
The researchers calculated that those who ate 300 milligrams of cholesterol daily – about 11⁄2 eggs – were 17 per cent more likely to develop heart disease than whose who didn’t eat eggs.
The researchers based their conclusions on what participants said they ate at the start of each study. They took into account high blood pressure, smoking, obesity and other traits that could contribute to heart problems.
Senior author Norrina Allen, a preventive medicine specialist, noted that the study lacked information on whether participants ate eggs hard-boiled, poached, fried, or scrambled in butter, which she said could affect health risks.
Eggs are a leading source of dietary cholesterol, which once was thought to be strongly related to blood cholesterol levels and heart disease.
Older studies suggesting that link led to nutrition guidelines almost a decade ago that recommended consuming no more than 300mg of cholesterol daily – one egg contains about 186mg.
Newer research questioned that relationship, finding that saturated fats contribute more to unhealthy levels of blood cholesterol that can lead to heart problems. The latest US government nutrition guidelines, from 2015, removed the strict daily cholesterol limit.
While eating as little cholesterol as possible is still advised, the recommendations say eggs can still be part of a healthy diet, as a good source of protein, along with lean meat, poultry, beans and nuts. Nutrition experts say the new study is unlikely to change that advice.
Dr Frank Hu of Harvard University noted that most previous studies had shown that eating a few eggs weekly was not linked with risks for heart disease in generally healthy people.
He doubted the study would change general healthy eating guidelines that emphasised fruits, vegetables, whole grains, nuts and beans, and limited processed meats and sugar.
Dr Rosalind Coleman, a professor of nutrition and paediatrics at the University of North Carolina, offered broader advice.
‘‘The main message for the public is not to select a single type of food as ‘bad’ or ‘good’ but to evaluate your total diet in terms of variety and amount,’’ she said.