The Evolution of Dietary Cholesterol Recommendations

Eggs – a nutrient-dense food once misunderstood for fat and cholesterol content – are now considered a valuable part of healthy eating patterns. The Dietary Guidelines for Americans includes eggs in all three recommended healthy dietary patterns and in 2015 removed the previous recommendation to limit daily cholesterol intake to <300mg. What’s more, the American Heart Association now advises that healthy adults can include one egg daily in a heart-healthy diet.

How did that happen?

Because authoritative dietary guidance is developed based on the body of scientific evidence available at the time, it makes sense that dietary guidance toward eating for heart health has advanced as new research has improved our understanding. New recommendations around eggs and cholesterol are understandably a point of confusion for many consumers. Therefore, it is important for healthcare professionals to understand the history of recommendations and how guidance has evolved over time. Read on to learn more…

• In the U.S., the first dietary cholesterol recommendations were issued in the 1960s and 1970s. In the 1960s, the recommendations to reduce dietary cholesterol stemmed from evidence in a few areas, including animal models demonstrating that dietary cholesterol can increase atherosclerosis.¹ However, the concentration of cholesterol used in these studies was extremely high, providing no practical application for human diets. In addition, many early human studies led to prediction equations that estimate the impact of dietary cholesterol on total blood cholesterol in isolation. Because humans consume cholesterol as part of whole foods and meals, the practical application of this research to health outcomes is limited.
• In 1968, the American Heart Association recommended consuming less than 300mg cholesterol per day and ≤3 eggs per week.
• In 1977, the Dietary Goals for the United States similarly encouraged Americans to “reduce cholesterol consumption to about 300 mg/day.”^2,3 While these were the best recommendations at the time, the details of these early reports indicate uncertainty around the impact of dietary cholesterol on heart disease. Nonetheless, the recommended 300 mg/day cholesterol limit became part of authoritative U.S. dietary guidance.
• The Dietary Guidelines for Americans (DGAs), first published in 1980 and updated every five years, reflect an evolution of the science around dietary cholesterol. While the DGAs highlight the best available evidence at the time, there has been uncertainty reflected in the language used around specific topics, including dietary cholesterol, throughout the various DGA versions.
• In 2013, after decades of research, the American Heart Association (AHA) and the American College of Cardiology (ACC) published a report on lifestyle management to reduce cardiovascular risk⁴. This report was an updated review of the science in which the authors concluded, “There is insufficient evidence to determine whether lowering dietary cholesterol reduces LDL-c.” A systematic review and meta-analysis cited in this report and published in the Journal of Clinical Nutrition concluded that egg consumption is not associated with cardiovascular disease or cardiac mortality risk in the general population.⁵
• In alignment with the AHA/ACC report, the 2015 Dietary Guidelines for Americans removed the 300 mg/day cholesterol limit and placed a new focus on healthy dietary patterns. ⁶
• In 2020, Harvard researchers analyzed up to 32 years of follow-up results from three observational studies and found that moderate egg consumption (defined as up to one egg per day), is not associated with cardiovascular disease risk overall. ⁷
• The current 2020-2025 DGAs affirm that eggs are a nutrient-dense food and recommend egg consumption within the context of healthy dietary patterns. The Dietary Guidelines for Americans (DGA) are based on decades of data and nutrition research and will continue to be updated as we gain new insights from scientific research. The American Heart Association also includes eggs as part of healthy dietary patterns. ^8,9

Try these recipes that fit into a heart-healthy diet.

Photo by Sara Haas, RDN.