Eggs, Cholesterol and Heart Health
Eggs, Cholesterol and Heart Health
Cardiovascular Disease in Australia
The latest National Health Survey (2017-2018) found 16.6% of Australians are living with cardiovascular disease1. One risk factor for cardiovascular disease, among many, is having high cholesterol levels. In Australia, one in three adults have abnormal or high total cholesterol and/or LDL cholesterol levels2. While it is important to understand the dietary and lifestyle factors which negatively impact cholesterol levels, it is also important to assess the totality of risk factors an individual has.
There are many factors that contribute to heart disease risk. These include non-modifiable factors such as age, gender, genetics and ethnicity, as well as a range of modifiable factors including diet, exercise, alcohol consumption and smoking3.
Historically, research has focused on individual dietary components such as nutrients or single foods when it comes to assessing the factors that impact blood cholesterol levels. More recently, however increasing attention has been given to the importance of overall dietary patterns and the overall context of consumption that impacts lipid levels and overall heart disease risk4,5. National and international heart associations emphasise dietary patterns that include a balanced combination of food, chosen regularly over time4-5.
While specific nutrient targets aren’t emphasized, the dietary patterns that are encouraged are naturally low in saturated and trans fat, salt and added sugar and rich in unsaturated fats (MUFA, omega-3 PUFA and omega-6 PUFA) along with wholegrains, fibre and antioxidants4. Any specific limits or restrictions on dietary cholesterol intake are seldom included in guidelines given dietary cholesterol intake has a minimal impact on blood cholesterol levels6.
National and International recommendations - Diet & Heart Health
Drawing from common features in heart healthy eating patterns, including the DASH and Mediterranean Diets, The Heart Foundation (of Australia) encourages people to eat plenty of vegetables, fruits and wholegrains; a variety of healthy protein sources including fish and legumes, eggs and lean poultry; unflavoured milk, yoghurt and cheese; healthy fat choices (such as nuts, seeds, avocado and olives) and suggests herbs and spices are used to flavour foods, instead of adding salt4. Eggs are encouraged amongst other protein foods with no specific guidelines on quantity for the general population. For individuals at higher risk of heart disease, the Heart Foundation suggest a maximum intake of 7 eggs per week6.
The most recent American Heart Association (AHA) guidelines for the prevention of cardiovascular disease5 emphasise the need for individuals to: “consume a healthy diet that emphasizes the intake of vegetables, fruits, nuts, whole grains, lean vegetable or animal protein, and fish and minimizes the intake of trans fats, red meat and processed red meats, refined carbohydrates, and sweetened beverages”, with no specific guidelines given relating to egg or dietary cholesterol consumption7.
Dietary cholesterol, cholesterol levels and heart disease risk
It is known that individuals vary in their response to dietary cholesterol intake. Approximately 25% of the population have been defined as “hyper-responders” - a term used to describe those who experience an increase in LDL and HDL-cholesterol levels following intake of dietary cholesterol. Importantly, approximately 75% of the population experience moderate to no difference in serum cholesterol levels following intakes of dietary cholesterol and are therefore described as “normal responders” or “hypo-responders”8-11.
The mechanism by which the majority of the population regulates blood cholesterol levels is that when dietary cholesterol intake increases, there is a subsequent decrease in cholesterol absorption and/or endogenous cholesterol synthesis12.
It has now been established that the impact of dietary cholesterol intake on blood lipids is minimal in most people6,13. Even when cholesterol levels rise, research has demonstrated that the LDL:HDL cholesterol ratio – a risk factor for heart disease - is maintained13,14.
Eggs, cholesterol levels and heart disease risk
Eggs are relatively low in saturated fat (3.4g per serve) and while they do contain cholesterol (398mg per serve), a number of studies have demonstrated they can be incorporated into a healthy dietary pattern without significant impact on cholesterol levels, particularly in healthy adults15-19. When it comes to heart disease risk, the most recent systematic reviews of cohort studies indicate no association between egg intake and increased risk of coronary heart disease in the general population20,21. This corroborates the 2013 Australian Dietary Guidelines review of scientific literature which concluded that the “consumption of eggs daily is not associated with increased risk of coronary heart disease” 22.
In higher risk individuals, such as those with diabetes, the Heart Foundation encourages a limit of 7 eggs per week6. This recommendation is based on some observational studies have found an association between higher egg intake and heart disease risk in this subgroup23-26.
Importantly, well-designed intervention studies do not indicate that higher egg intake has adverse effects on heart disease risk in individuals with or at risk of type 2 diabetes. A 2017 systematic review of six randomised controlled trials concluded that the consumption of 6 to 12 eggs per week, in the context of a diet that is consistent with guidelines on cardiovascular health promotion, has no adverse effect on major CVD risk factors in individuals at risk for developing diabetes or with type 2 diabetes27.
Furthermore, since the 2017 systematic review, the results of an Australian 12-month intervention study have been published which support the conclusion that eggs can be enjoyed by individuals with (or at risk of) type 2 diabetes. In the DIABEGG study, consuming ≥12 eggs per week produced no detrimental outcomes in CVD risk factors (including cholesterol, triglycerides, inflammatory markers, oxidative stress or measures of glycemia) for individuals with prediabetes or type 2 diabetes and overweight or obesity28. These 12 month findings are an extension of the original 3-month DIABEGG study which showed that high egg (≥12 eggs per week) consumption vs low egg (<2 eggs per week) consumption, as part of a weight maintenance diet, had no detrimental effect on CVD risk factors29.
For more information on the DIABEGG study watch this video from Dr. Nick Fuller here.
Nutritional Benefits of Eggs
One serve of eggs provides 13 different essential vitamins and nutrients, including quality protein and can be included in a heart healthy eating pattern.
Eggs are relatively low in saturated fat, containing 3.4g per serve. The majority of the fat in eggs (68%), is healthy unsaturated fats including monounsaturated fat (5.3g per serve) and polyunsaturated fat (1.7g per serve). This includes heart healthy omega-3 fats (180mg per serve).
Eggs also contain lutein and zeaxanthin – dietary carotenoids with antioxidant and anti-inflammatory properties - which have also been associated with heart health benefits30.
Overall, the scientific evidence indicates eggs can be enjoyed as part of a heart healthy dietary pattern. Dietary cholesterol has a minimal impact on cholesterol levels and egg intake has a neutral impact on heart health – neither remarkably increasing or decreasing risk in the general population8.
With respect to eggs and heart health:
- Eggs may be consumed daily as part of a heart healthy dietary pattern, in line with the Heart Foundation of Australia’s recommendations, as well as the NHMRC’s Australian Dietary Guidelines.
- Eggs should be considered in a similar way as other protein rich whole foods and selected as part of a varied diet that is low in saturated fat and contains a variety of cardio-protective foods such as fish, wholegrains, fruit, vegetables, legumes, nuts and seeds.
- Recommended heart healthy patterns, which emphasise the intake of a variety of whole foods, are naturally low in saturated and trans fats, salt and added sugar and rich in wholegrains, fibre, antioxidants and unsaturated fats (omega-3 and omega-6).
- In individuals at high risk of heart disease, such as people with diabetes, the Heart Foundation suggests a limit of 7 eggs per week. This is prudent advice while further research in this area is conducted [Refer to Australian Egg’s position statement on Eggs and Diabetes for more details in this area.]
This statement is for healthcare professionals only.
*One serve = 2x60g eggs (104g edible portion)
As diet-induced changes in total cholesterol and lipoproteins vary considerably between individuals, Australian Eggs recommends individual discussion of the recommendations regarding egg intake with their healthcare professional.
For patient-friendly information about eggs and cholesterol click here.
Heart Foundation: www.heartfoundation.org.au
Australian Dietary Guidelines: www.eatforhealth.gov.au/guidelines
- Heart Foundation (2021). Key Statistics: Cardiovascular Disease: Statistics and information on Cardiovascular disease in Australia. https://www.heartfoundation.org.au/activities-finding-or-opinion/key-stats-cardiovascular-disease
- Australian Bureau of Statistics. Australian Health Survey: Biomedical Results for Chronic Diseases, 2011-12 (Australian Bureau of Statistics, Canberra, ACT, Australia, 2013).
- Heart Foundation (2021). Are you at risk of heart disease? https://www.heartfoundation.org.au/heart-health-education/are-you-at-risk-of-heart-disease
- Heart Foundation (2019) Heart Healthy Eating Patterns: Position Statement. NHFA:Melbourne
- Carson JAS, Lichtenstein AH, Anderson CAM, Appel LJ, Kris-Etherton PM, Meyer KA, Petersen K, Polonsky T, Van Horn L; American Heart Association Nutrition Committee of the Council on Lifestyle and Cardiometabolic Health; Council on Arteriosclerosis, Thrombosis and Vascular Biology; Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; Council on Peripheral Vascular Disease; and Stroke Council. Dietary Cholesterol and Cardiovascular Risk: A Science Advisory From the American Heart Association. Circulation. 2020 Jan 21;141(3):e39-e53.
- Heart Foundation (2019). Eggs and Heart Healthy Eating: Position Statement. NHFA:Melbourne
- Arnett, D. K., Blumenthal, R. S., Albert, M. A., Buroker, A. B., Goldberger, Z. D., Hahn, E. J., Himmelfarb, C. D., Khera, A., Lloyd-Jones, D., McEvoy, J. W., Michos, E. D., Miedema, M. D., Muñoz, D., Smith, S. C., Virani, S. S., Williams, K. A., Yeboah, J., & Ziaeian, B. (2019). 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. In Circulation (Vol. 140, Issue 11, pp. e596–e646). NLM (Medline). https://doi.org/10.1161/CIR.0000000000000678
- Herron, K.L., et al. The ABCG5 polymorphism contributes to individual responses to dietary cholesterol and carotenoids in eggs. J Nutr 136, 1161-1165 (2006).
- Howell, W.H., McNamara, D.J., Tosca, M.A., Smith, B.T. & Gaines, J.A. Plasma lipid and lipoprotein responses to dietary fat and cholesterol: a meta-analysis. Am J Clin Nutr 65, 1747-1764 (1997).
- Katan, M.B. & Beynen, A.C. Characteristics of human hypo- and hyperresponders to dietary cholesterol. Am J Epidemiol 125, 387-399 (1987).
- Katan, M.B., Beynen, A.C., de Vries, J.H. & Nobels, A. Existence of consistent hypo- and hyperresponders to dietary cholesterol in man. Am J Epidemiol 123, 221-234 (1986).
- McNamara, D.J., et al. Heterogeneity of cholesterol homeostasis in man. Response to changes in dietary fat quality and cholesterol quantity. J Clin Invest 79, 1729-1739 (1987).
- 13. Vincent, M. J., Allen, B., Palacios, O. M., Haber, L. T., & Maki, K. C. (2018). Meta-regression analysis of the effects of dietary cholesterol intake on LDL and HDL cholesterol. The American Journal of Clinical Nutrition, [Epud ahea. https://doi.org/10.1093/ajcn/nqy273
- Rouhani, M.H., Rashidi-Pourfard, N., Salehi-Abargouei, A., Karimi, M. & Haghighatdoost, F. Effects of Egg Consumption on Blood Lipids: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. J Am Coll Nutr [Epud ahead of print], 1-12 (2017).
- DiMarco, D.M., Norris, G.H., Millar, C.L., Blesso, C.N. & Fernandez, M.L. Intake of up to 3 Eggs per Day Is Associated with Changes in HDL Function and Increased Plasma Antioxidants in Healthy, Young Adults. J Nutr 147, 323-329 (2017).
- Katz, D.L., et al. Egg consumption and endothelial function: a randomized controlled crossover trial. Int J Cardiol 99, 65-70 (2005).
- Rueda, J.M. & Khosla, P. Impact of breakfasts (with or without eggs) on body weight regulation and blood lipids in university students over a 14-week semester. Nutrients 5, 5097-5113 (2013).
- Clayton, Z.S., et al. Influence of Resistance Training Combined with Daily Consumption of an Egg-based or Bagel-based Breakfast on Risk Factors for Chronic Diseases in Healthy Untrained Individuals. J Am Coll Nutr 34, 113-119 (2015).
Vergara M, Hauser ME, Aronica L, Rigdon J, Fielding-Singh P, Shih CW, Gardner CD. Associations of Changes in Blood Lipid Concentrations with Changes in Dietary Cholesterol Intake in the Context of a Healthy Low-Carbohydrate Weight Loss Diet: A Secondary Analysis of the DIETFITS Trial. Nutrients. 2021 Jun 4;13(6):1935 https://pubmed.ncbi.nlm.nih.gov/34200027/
- Drouin-Chartier, J.-P., Chen, S., Li, Y., Schwab, A. L., Stampfer, M. J., Sacks, F. M., Rosner, B., Willett, W. C., Hu, F. B., & Bhupathiraju, S. N. (2020). Egg consumption and risk of cardiovascular disease: three large prospective US cohort studies, systematic review, and updated meta-analysis. BMJ (Clinical Research Ed.), 368, m513. https://doi.org/10.1136/bmj.m513
- Krittanawong C, NarasimhanB, Wang Z, et al. Association Between Egg Consumption and Risk of Cardiovascular Outcomes: A Systematic Review and Meta-Analysis [published online ahead of print, 2020 Jul 9].Am J Med. 2020;S0002-9343(20)30549-0. doi:10.1016/j.amjmed.2020.05.046
- National Health and Medical Research Council. Australian Dietary Guidelines. (ed. National Health and Medical Research Council) (NHMRC, Canberra, ACT, Australia, 2013).
- Shin, J. Y., Xun, P., Nakamura, Y., & He, K. (2013). Egg consumption in relation to risk of cardiovascular disease and diabetes: a systematic review and meta-analysis. The American Journal of Clinical Nutrition, 98(1), 146–159. https://doi.org/10.3945/ajcn.112.051318
- Li, Y., Zhou, C., Zhou, X., & Li, L. (2013). Egg consumption and risk of cardiovascular diseases and diabetes: a meta-analysis. Atherosclerosis, 229(2), 524–530. https://doi.org/10.1016/j.atherosclerosis.2013.04.003 S0021-9150(13)00243-8 [pii]
- Rong, Y., Chen, L., Zhu, T., Song, Y., Yu, M., Shan, Z., Sands, A., Hu, F. B., & Liu, L. (2013). Egg consumption and risk of coronary heart disease and stroke: dose-response meta-analysis of prospective cohort studies. BMJ (Clinical Research Ed.), 346, e8539. https://doi.org/10.1136/bmj.e8539 bmj.e8539 [pii]
- Tran, N. L., Barraj, L. M., Heilman, J. M., & Scrafford, C. G. (2014). Egg consumption and cardiovascular disease among diabetic individuals: a systematic review of the literature. Diabetes Metab Syndr Obes, 7, 121–137. https://doi.org/10.2147/DMSO.S58668 dmso-7-121 [pii]
- Richard, C., et al. Impact of Egg Consumption on Cardiovascular Risk Factors in Individuals with Type 2 Diabetes and at Risk for Developing Diabetes: A Systematic Review of Randomized Nutritional Intervention Studies. Can J Diabetes (2017).
- Fuller, N.R., et al. Effect of a high-egg diet on cardiometabolic risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) Study—randomized weight-loss and follow-up phase. Am J Clin Nutr [Epud ahead of print], nqy048-nqy048 (2018).
- Fuller, N.R., et al. The effect of a high-egg diet on cardiovascular risk factors in people with type 2 diabetes: the Diabetes and Egg (DIABEGG) study—a 3-mo randomized controlled trial. Am J Clin Nutr[Epub ahead of print](2015).
- Leermakers, E.T., et al. The effects of lutein on cardiometabolic health across the life course: a systematic review and meta-analysis. Am J Clin Nutr 103, 481-494 (2016).