Medical Research: What are the main findings of the study?
Dr. Katz: We did not see any adverse effects of short-term, daily egg ingestion in adults with established coronary artery disease.
Medical Research: What was most surprising about the results?
Dr. Katz: Eggs are routinely banned from ‘heart healthy diets.’ in particular eggs are always absent from cardiac care units, with egg beaters substituting. However, these same units routinely serve products with refined starch and added sugar. The scientific basis for excluding eggs from diets to improve cardiac health has long been suspect. Here, we show that in the short term at least, there are no discernible harms of daily egg ingestion even in adults with heart disease.
Medical Research: What should clinicians and patients take away from your report?
Dr. Katz: Our motivation for this line of research- which includes two prior studies- was that people don’t just remove foods from their diets; they replace them. So people eating fewer eggs might wind up eating more oatmeal, which might improve their cardiac health. But they also might wind up eating more donuts and danish, which clearly would not. Our findings, in context, suggest that eggs can certainly be included in a heart-healthy diet by those so inclined. We have no evidence that eating eggs reduces cardiac risk, but excluding them might increase it if poor substitutions are made. If eggs are incorporated into diets as a high-quality protein source, they might replace other foods, such as fatty meats, that are less heart-healthy. Our on-going work looks at egg inclusion vs. Egg exclusion, and the effects on overall diet quality in general.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Katz: That failure to consider food substitutions is a prevailing blind spot in nutritional epidemiology. We need more research exploring the notion that when we advise people to stop eating x, they may eat more y. So- what is y?- matters a lot. Similarly, when we tell people to eat y, they may stop eating x. What was x?
As for eggs, as noted, there is no clear evidence they reduce cardiac risk per se. But the idea that their cholesterol content means they need to be banished from cardiac-conscious diets is obsolete.