For decades, nutrition guidelines advised limiting eggs because it was thought that they raised blood cholesterol and had adverse heart and metabolic effects. While such restrictions have largely been lifted for the general population in recent years, the recommendation for people with diabetes has remained murkier because of mixed research findings, with observational studies tending to suggest unfavorable effects of eggs. But clinical trials, which can establish causation, have had more encouraging results-and now, a recent Australian study in the American Journal of Clinical Nutrition offers the best evidence yet that people with diabetes don’t need to strictly limit eggs.
The study, supported by the egg industry, builds on a 2015 study that randomly assigned 140 overweight or obese people with prediabetes or type 2 diabetes (T2D) to either a high egg intake (two eggs a day) or low egg intake (less than two a week) for three months; all participants followed a healthy diet that emphasized replacing saturated fats (as in butter) with unsaturated fats (as in vegetable oils and avocado). At the end, the researchers found no differences in blood cholesterol, triglycerides, and glycemic control between the groups.
For the new analysis, the participants were followed for an additional nine months, during which time they continued their high or low egg intake. As was found earlier, the high-egg group had no adverse changes in those cardiovascular disease markers. In addition, there were no changes in markers of inflammation or oxidative stress at any point in the follow-up period. Combining the two studies makes this the longest clinical assessment of the cardiovascular effects of eggs in a diabetic population. According to the authors, their findings “suggest that a high-egg diet is safe for those with T2D-just as for the general population.” The study did not, however, look at actual cardiovascular outcomes.