(CNN) It's health's longest ping pong game: Eggs are bad -- then good -- then bad for your heart.

According to a new study, the latest answer might have come from your mother or grandmother: all things in moderation.

"Moderate consumption -- up to one egg per day -- is not associated with increased risk of cardiovascular disease," said study author Dr. Frank Hu, who chairs the department of nutrition at Harvard University's T.H. Chan School of Public Health.

The research team analyzed data from large, longitudinal studies that were following 215,000 women and men who had no major chronic disease at the start of the study.

All were asked about their egg-eating habits -- most said they ate between one and five eggs a week -- and their health was followed over a 34-year period.