In this article we will investigate whether the cholesterol content of the egg is harmful to health, particularly in relation to heart disease. We have mentioned previously in articles that the "dietary cholesterol hypothesis" - as a prime causative factor - in heart disease is incorrect. On the basis of this flawed hypothesis much advice has been given on diet that includes abandonment of extremely beneficial whole foods, one of which is the egg.
In this article we want to address this issue and dispel this false notion. First we will look briefly at the nutritional value of eggs and then go into some research papers.
Nutrients in the egg
First, the egg does indeed contain cholesterol and plenty of it - in its yolk at over 200mg. It is also rammed with crucial nutrients, along with many fat-soluble vitamins and amino acids. The egg is so nutritious all-round that consuming them daily would take care of most many vitamin and mineral deficiencies. The egg-yolk is more nutritious than the egg white. Most of the very important nutrients are in the egg-yolk.
From published nutrional data, an egg typically contains:
Consuming eggs regularly would help meet most nutritional requirements in terms of minerals and vitamins. The most advisable way of having eggs is by boiling them. Frying (omelettes, fried eggs) is a detrimental process, it leads to nutrient loss as well as oxidation of lipids, which are harmful in the body. Also frying eggs in highly-reactive, oxidizable, polyunsaturated vegetable oils is not a good idea at all.
Around half of all heart-attacks occur in people with normal to low cholesterol levels. Total cholesterol levels on their own, and LDL levels on their own, do not independently equate to increased risk of heart disease. We hope to expand upon this in more detail in separate articles.
The Framingham Study has investigated the effect of host and environmental factors on the development of coronary heart disease since 1949. Serum cholesterol level was determined to the one of the risk factors for coronary heart disease. The nutrient intake, in a subsample of the study population, was determined in 1957. A review of this material has permitted an estimate of egg consumption on each of 912 subjects. The serum cholesterol distribution curves of the subjects according to tertile of egg intake were almost identical, and no relationship between egg intake and coronary heart disease incidence was found. It is concluded that within the range of egg intake of this population differences in egg consumption were unrelated to blood cholesterol level or to coronary heart disease incidence.
The recommendation that not more than 300 mg cholesterol be consumed daily to prevent high serum cholesterol levels and coronary heart disease is often used to justify a restriction of egg intake to three or four per week. One egg contains about 200 mg of cholesterol, but eggs are also excellent and relatively inexpensive sources of essential amino acids and certain vitamins. In this paper, the place of eggs in a prudent, cholesterol-lowering diet as a substitute for other animal products, is scrutinised. The extra cholesterol, where considered as the only variable, will increase serum cholesterol levels, but the effect is relatively small. The exclusion of eggs from the diet should be weighed against deprivation of essential nutrients especially in vulnerable groups. While restriction of egg intake in westernised populations seems justifiable, the upper limit of three or four per week may not always be applicable, depending on the overall diet and lipid profile of the individual.
Regarding the statements of the authors, "The extra cholesterol, where considered as the only variable, will increase serum cholesterol levels, but the effect is relatively small", it is important to clarify that where dietary intake of cholesterol increases blood cholesterol, there is an increase in both LDL and HDL, and the increase in LDL is with respect to large particle sized LDL (better than the small particle-sized LDL), so the net overall effect - for those believing primarily in the cholesterol hypothesis - is that the effect is negligible, since HDL also increases pushing the TC/HDL factor down, or at the same level. This is considering that for those assuming the cholesterol-hypothesis, the best marker for determining cholesterol as a "risk factor" is the ratio of TC/HDL (total cholesterol to HDL). The advice of the authors that restriction of eggs in westernised populations "seems justifiable" and that an "upper limit of three or four a week may not always be applicable" - indicates that their study proves there is little basis against cautioning against eggs. Also see the research papers below for more clarification on this.
Kritchevsky SB, Kritchevsky D. Department of Preventive medicine, University of Tennessee health Sciences Center, Memphis 38105, USA. Egg consumption and coronary heart disease: an epidemiologic overview. J Am Coll Nutr. 2000 Oct;19(5 Suppl):549S-555s
Serum cholesterol has been established as a modifiable risk factor for coronary heart disease. Experimental feeding studies show that saturated fat and cholesterol increase serum cholesterol levels; thus, dietary recommendations for lowering the risk of heart disease proscribe the intake of both substances. Recommendations have also included limits on the intake of eggs because of their high cholesterol content. In free-living populations, diet reflects a pattern of associated choices. Increases in one food may lead to changes in the consumption of other foods that may modulate disease risk. Epidemiologic data are helpful in assessing the importance of foods and nutrients in the context in which they are actually consumed. We review epidemiologic data relating dietary cholesterol and eggs to coronary disease risk. Cholesterol intake was associated with a modest increase in the risk of coronary events. The true magnitude of the association is difficult to estimate because most studies fail to account for potential confounding by other features of the diet. When a full-range of confounding factors was considered, the association between cholesterol intake and heart disease risk was small (6% increase in risk for 200mg/1,000kcal/day difference in cholesterol intake). Several studies have examined egg intake and its relationship with coronary outcomes. All but one failed to consider the role of other potentially confounding dietary factors. When dietary confounders were considered, no association was seen between egg consumption at levels up to 1 + egg per day and the risk of coronary heart disease in non-diabetic men and women.
Fernandez ML. Department of Nutritional Sciences, University of Connecticut, Storrs, Connecticut 06269, USA. Dietary cholesterol provided by eggs and plasma lipoproteins in healthy populations. Curr Opin Clin Nutr Metab Care. 2006 Jan;9(1):8-12.
PURPOSE OF REVIEW: Extensive research has not clearly established a link between egg consumption and risk for coronary heart disease. The effects of egg intake on plasma lipids and low-density lipoprotein (LDL) atherogenicity in healthy populations need to be addressed. RECENT FINDINGS: The lack of connection between heart disease and egg intake could partially be explained by the fact that dietary cholesterol increases the concentrations of both circulating LDL and high-density lipoprotein (HDL) cholesterol in those individuals who experience an increase in plasma cholesterol following egg consumption (hyperresponders). It is also important to note that 70% of the population experiences a mild increase or no alterations in plasma cholesterol concentrations when challenged with high amounts of dietary cholesterol (hyporesponders). Egg intake has been shown to promote the formation of large LDL, in addition to shifting individuals from the LDL pattern B to pattern A, which is less atherogenic. Eggs are also good sources of antioxidants known to protect the eye; therefore, increased plasma concentrations of lutein and zeaxanthin in individuals consuming eggs are also of interest, especially in those populations susceptible to developing macular degeneration and eye cataracts. SUMMARY: For these reasons, dietary recommendations aimed at restricting egg consumption should not be generalized to include all individuals. We need to acknowledge that diverse healthy populations experience no risk in developing coronary heart disease by increasing their intake of cholesterol but, in contrast, they may have multiple beneficial effects by the inclusion of eggs in their regular diet.
Greene CM, Zern TL, Wood RJ, Shrestha S, Aggarwal D, Sharman MJ, Volek JS, Fernandez ML. Departments of Nutritional Science, University of Connecticut, Storrs, CT 06269, USA. Maintenance of the LDL cholesterol:HDL cholesterol ratio in an elderly population given a dietary cholesterol challenge. J Nutr. 2005 Dec;135(12):2793-8.
We previously evaluated the responses to dietary cholesterol in children and young adults. In this study, the effects of dietary cholesterol on plasma lipids and LDL atherogenicity were evaluated in 42 elderly subjects (29 postmenopausal women and 13 men > 60 y old). Our exclusion criteria were diabetes, heart disease, and the use of reductase inhibitors. The study followed a randomized crossover design in which subjects were assigned to consume the equivalent of 3 large eggs (egg) daily or the same amount of a cholesterol-free, fat-free egg substitute (SUB) for a 1-mo period. After a 3-wk washout period, subjects were assigned to the alternate treatment. The concentration of plasma cholesterol after the egg period varied among subjects. When all subjects were evaluated, there were significant increases in LDL cholesterol (LDL-C) (P < 0.05) and HDL-C (P < 0.001) for both men and women during the egg period, resulting in no alterations in the LDL-C:HDL-C or the total cholesterol:HDL-C ratios. In addition, the LDL peak diameter was increased during the egg period for all subjects. In contrast, the measured parameters of LDL oxidation, conjugated diene formation, and LDL lag time did not differ between the egg and the SUB periods. We conclude from this study that dietary cholesterol provided by eggs does not increase the risk for heart disease in a healthy elderly population.
The next paper makes some excellent observations, those which are largely in agreement with what we hold - namely, that maintaining a wholesome, nutrient-rich diet, balanced in quality and quantity, is the best way to preserve health.
Kritchevsky SB. A review of scientific research and recommendations regarding eggs. J Am Coll Nutr. 2004 Dec;23(6 Suppl):596S-600S. Sticht Center on aging, Department of Internal medicine, Section on Gerontology and Geriatric medicine, Wake Forest University School of medicine, Medical Center Boulevard, Winston-Salem, NC 27157, USA.
For much of the past 40 years, the public has been warned away from eggs because of a concern over coronary heart disease risk. This concern is based on three observations: 1. Eggs are a rich source of dietary cholesterol; 2. when fed experimentally, dietary cholesterol increases serum cholesterol and; 3. high serum cholesterol predicts the onset of coronary heart disease. However, data from free-living populations show that egg consumption is not associated with higher cholesterol levels. Furthermore, as a whole, the epidemiologic literature does not support the idea that egg consumption is a risk factor for coronary disease. Within the nutritional community there is a growing appreciation that health derives from an overall pattern of diet rather than from the avoidance of particular foods, and there has been a shift in the tone in recent dietary recommendations away from "avoidance" messages to ones that promote healthy eating patterns. The most recent American heart Association guidelines no longer include a recommendation to limit egg consumption, but recommend the adoption of eating practices associated with good health. Based on the epidemiologic evidence, there is no reason to think that such a healthy eating pattern could not include eggs.
Mayurasakorn K, Srisura W, Sitphahul P, Hongto PO. Department of Social medicine, Samutsakhon General Hospital, Samutsakhon 74000, Thailand. High-density lipoprotein cholesterol changes after continuous egg consumption in healthy adults. J Med Assoc Thai. 2008 Mar;91(3):400-7.
OBJECTIVE: To determine the relationship between continuous egg consumption with Thai life-style dietary and serum lipids of healthy young people. MATERIAL AND METHOD: Fifty-six participants with an average age of 35 were enrolled. In an experimental method of cholesterol intake, all participants were fed an additional egg per day to their basic diet. This project ran for 12 weeks. RESULTS: The 12-week egg consumption significantly increased serum total cholesterol by 0.27 +/- 0.15 mmol/L (10.43 +/- 5.80 mg/dL) (p < 0.05). The HDL-cholesterol (HDL-c) increased significant by 0.55 +/- 0.06 mmol/L (21.80 +/- 2.25 mg/dL) (p < 0.001) while the total cholesterol (TC) decreased as the HDL-c ratio was 0.94 +/- 1.1 (p < 0.001). No significant changes were found in LDL-cholesterol (LDL-c) and triglyceride levels. The present study showed that small serum LDL-c changed in response to change of egg consumption. Additionally, 12-week egg consumption also resulted in an increasing HDL-c level. CONCLUSION: In the majority of healthy adults, an addition of one egg per day to a normal fat diet could raise HDL-c levels and decreased the ratio of TC to HDL-c. Therefore, egg consumption might benefit blood cholesterol.
The overall effect of the egg consumption was to raise HDL levels, with no effect on LDL and triglyceride levels.
And here is another study in Denmark with similar findings:
Schnohr P, Thomsen OO, Riis Hansen P, Boberg-Ans G, Lawaetz H, Weeke T. Loegernes Test Centre, Clinic for Preventive health Examinations, Copenhagen, Denmark. Egg consumption and high-density-lipoprotein cholesterol. J Intern Med. 1994 Mar;235(3):249-51.
OBJECTIVES. To examine if increased egg consumption raises serum high-density-lipoprotein (HDL) cholesterol in healthy individuals. DESIGN. A cross-over study. SETTING. A private clinic for preventive health examinations in Copenhagen. SUBJECTS. Twenty-four healthy adults, 12 men and 12 women, aged 23-52 (median 40) years. INTERVENTIONS. After a 1-week control period each person added two boiled eggs to the usual daily diet for 6 weeks. All persons were instructed not to change the lifestyle in other ways during the whole study period. MAIN OUTCOME MEASURES. Serum HDL cholesterol, total cholesterol and triglycerides were measured before, during and after 6 weeks of extra egg consumption. The corresponding serum low-density-lipoprotein (LDL) cholesterol was calculated from the Friedewald formula. RESULTS. After 6 weeks of extra egg consumption serum HDL cholesterol increased by 10% (P < 0.05) and total cholesterol increased 4% (P < 0.05), whereas the ratio total cholesterol/HDL cholesterol did not change significantly. Serum triglycerides and LDL cholesterol were also unchanged. CONCLUSIONS. A moderate egg intake should not be rigorously restricted in healthy individuals.
Katz DL, Evans MA, Nawaz H, Njike VY, Chan W, Comerford BP, Hoxley ML. Yale Prevention Research Center, 130 Division Street, Derby, CT 06418, USA. Egg consumption and endothelial function: a randomized controlled crossover trial. Int J Cardiol. 2005 Mar 10;99(1):65-70.
CONCLUSION: Short-term egg consumption does not adversely affect endothelial function in healthy adults, supporting the view that dietary cholesterol may be less detrimental to cardiovascular health than previously thought.
The idea that dietary cholesterol increases risk of coronary heart disease (CHD) by turning into blood cholesterol is compelling in much the same way that fish oil improves arthritis by lubricating our joints! Dietary cholesterol, chiefly in the form of eggs, has long been outlawed as a causative agent in CHD through its association with serum cholesterol. However, the scientific evidence to support a role for dietary cholesterol in CHD is relatively insubstantial in comparison with the incontrovertible link between its circulating blood relative in low density lipoprotein (LDL) cholesterol and CHD.
Just a comment here, oxidized, small particle sized LDL-cholesterol are explained to have a role in the development of arteriosclerosis, however this in itself is not an primary underlying causative factor of the disease. In other words, levels of LDL-cholesterol are not an independent risk factor. Also read further, where the authors explain that in many conditions cardiovascular risk is independent of LDL-cholesterol. The study summary continues:
Interpretation of the relationship between dietary cholesterol and CHD has been repeatedly confounded by an often inseparable relationship between dietary cholesterol and saturated fat. It has also been exaggerated by the feeding of unphysiologically high intakes of eggs. Nonetheless, numerous studies have shown that dietary cholesterol can increase serum LDL-cholesterol, but the size of this effect is highly variable between individuals and, according to over 30 years of prospective epidemiology, has no clinically significant impact on CHD risk. Variation in response to dietary cholesterol is a real phenomenon and we can now identify nutrientgene interactions that give rise to this variation through differences in cholesterol homeostasis. More importantly, to view eggs solely in terms of the effects of their dietary cholesterol on serum cholesterol is to ignore the potential benefits of egg consumption on coronary risk factors, including obesity, diabetes and metabolic syndrome. Cardiovascular risk in these conditions is largely independent of LDL-cholesterol. These conditions are also relatively unresponsive to any LDL-cholesterol raising effects of dietary cholesterol. Treatment is focused primarily on weight loss, and it is in this respect that eggs may have a new and emerging role in facilitating weight loss through increased satiety.
Gisella Mutungi, Joseph Ratliff, Michael Puglisi, Moises Torres-Gonzalez, Ushma Vaishnav, Jose O. Leite, Erin Quann4, Jeff S. Volek and Maria Luz Fernandez. Department of Nutritional Sciences and Department of Kinesiology, University of Connecticut, Storrs, CT 06269 Nutrient Physiology, metabolism, and Nutrient-Nutrient Interactions Dietary cholesterol from eggs Increases Plasma HDL cholesterol in overweight Men Consuming a Carbohydrate-Restricted Diet. American Society for nutrition J. Nutr. 138:272-276, February 2008
Carbohydrate-restricted diets (CRD) significantly decrease body weight and independently improve plasma triglycerides (TG) and HDL cholesterol (HDL-C). Increasing intake of dietary cholesterol from eggs in the context of a low-fat diet maintains the LDL cholesterol (LDL-C)/HDL-C for both hyper- and hypo-responders to dietary cholesterol. In this study, 28 overweight/obese male subjects (BMI = 25-37 kg/m2) aged 40-70 y were recruited to evaluate the contribution of dietary cholesterol from eggs in a CRD. Subjects were counseled to consume a CRD (10-15% energy from carbohydrate) and they were randomly allocated to the egg group [intake of 3 eggs per day (640 mg/d additional dietary cholesterol)] or SUB group [equivalent amount of egg substitute (0 dietary cholesterol) per day]. Energy intake decreased in both groups from 10,243 ± 4040 to 7968 ± 2401 kJ (P < 0.05) compared with baseline. All subjects irrespective of their assigned group had reduced body weight and waist circumference (P < 0.0001). Similarly, the plasma TG concentration was reduced from 1.34 ± 0.66 to 0.83 ± 0.30 mmol/L after 12 wk (P < 0.001) in all subjects. The plasma LDL-C concentration, as well as the LDL-C:HDL-C ratio, did not change during the intervention. In contrast, plasma HDL-C concentration increased in the egg group from 1.23 ± 0.39 to 1.47 ± 0.38 mmol/L (P < 0.01), whereas HDL-C did not change in the SUB group. Plasma glucose concentrations in fasting subjects did not change. Eighteen subjects were classified as having the metabolic syndrome (MetS) at the beginning of the study, whereas 3 subjects had that classification at the end. These results suggest that including eggs in a CRD results in increased HDL-C while decreasing the risk factors associated with MetS.
What the above study found was that plasma LDL did not increase, but HDL did increase - showing a net beneficial effect.
Donald J. McNamara, pH.D. Egg nutrition Center, Washington, DC. The Impact of egg Limitations on Coronary heart disease Risk: Do the Numbers Add Up? Journal of the American College of nutrition, Vol. 19, No. 90005, 540S-548S (2000).
For over 25 years eggs have been the icon for the fat, cholesterol and caloric excesses in the American diet, and the message to limit eggs to lower heart disease risk has been widely circulated. The "dietary cholesterol equals blood cholesterol" view is a standard of dietary recommendations, yet few consider whether the evidence justifies such restrictions. Over 50 years of cholesterol-feeding studies show that dietary cholesterol does have a small effect on plasma cholesterol concentrations. The 167 cholesterol feeding studies in over 3,500 subjects in the literature indicate that a 100 mg change in dietary cholesterol changes plasma total cholesterol by 2.2 mg/dL. Today we recognize that dietary effects on plasma cholesterol must be viewed from effects on the atherogenic LDL cholesterol as well as anti-atherogenic HDL cholesterol since the ratio of LDL:HDL cholesterol is a major determinant of heart disease risk. Cholesterol feeding studies demonstrate that dietary cholesterol increases both LDL and HDL cholesterol with little change in the LDL:HDL ratio. Addition of 100 mg cholesterol per day to the diet increases total cholesterol with a 1.9 mg/dL increase in LDL cholesterol and a 0.4 mg/dL increase in HDL cholesterol. On average, the LDL:HDL ratio change per 100 mg/day change in dietary cholesterol is from 2.60 to 2.61, which would be predicted to have little effect on heart disease risk. These data help explain the epidemiological studies showing that dietary cholesterol is not related to coronary heart disease incidence or mortality across or within populations.
Another excellent paper published in the American Society for Nutritional Sciences is presented below we will take numerous quotes from it:
Kristin L. Herron and Maria Luz Fernandez. Are the Current Dietary Guidelines Regarding egg Consumption Appropriate? The American Society for Nutritional Sciences J. Nutr. 134:187-190, January 2004.
As a whole food, eggs are an inexpensive and low calorie source of nutrients such as folate, riboflavin, selenium, choline and vitamins B-12 and A. Eggs are also one of the few exogenous sources of vitamins K and D. Furthermore, eggs are a source of high quality protein, and the lipid matrix of the yolk serves to enhance the bioavailability of nutrients such as lutein and zeaxanthin. However, despite these benefits, to gain popular acceptance the controversy surrounding the dietary cholesterol content of eggs must be revisited and revised.
Cholesterol is a dietary component that has elicited much public and scientific interest in conjunction with CHD. Extensive research has failed to establish a definite link between dietary cholesterol intake and disease progression. Numerous population studies have clearly demonstrated the lack of a relationship between egg intake and CHD. A recent study, which examined the intake of 117,000 nurses and health professionals over a 14-y period, found no difference in the relative risk for CHD between those who consumed less than one egg a week and those who ate more than one egg a day. Furthermore, clinical studies have clearly shown that plasma compartment changes resulting from dietary cholesterol consumption are regulated by a vast number of genes, which allow for extensive individual variation in response. The classification of individual genetic differences may allow for the future identification of those who would respond favorably to dietary cholesterol restriction and those who are hyporesponsive to intake. It has been suggested that ~70% of humans are hyporesponsive to excess dietary cholesterol consumption. In addition, those individuals who hyperrespond generally experience elevations in both LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C) allowing for the maintenance of the LDL-C/HDL-C ratio, an important marker for CHD risk. This evidence suggests that for healthy individuals, the nutritional benefits clearly outweigh the concern surrounding the 213 mg of dietary cholesterol provided by one large egg.
And in the conclusion:
If judged as a whole food, and not simply as a source of dietary cholesterol, the positive contribution of eggs to a healthy diet becomes apparent. Because eggs are a conventional food containing nutrients that play fundamental roles beyond basic nutrition, their promotion as a functional food should be considered. This discussion has examined the possible role of egg nutrients in the prevention and treatment of specific symptoms associated with chronic age-related diseases. Furthermore, evidence has been presented showing that the current blanket recommendations regarding dietary cholesterol and egg intake are unwarranted for the majority of people and are not supported by scientific data. The assumptions made by these recommendations are that dietary cholesterol consumption >300 mg/d translates directly into elevated plasma cholesterol levels and the development of CHD in all individuals. These assumptions are clearly flawed. First, a conservative estimate suggests that only 30% of the population would respond to dietary cholesterol. It has been determined that a reduction in dietary cholesterol of 100 mg/d would only slightly decrease plasma total cholesterol levels of those who are responsive. For example, if a responsive individual chose to eat two eggs in one day they would exceed the AHA recommended upper limit for cholesterol intake by 126 mg, which would suggest that they may experience a 0.050.07 mmol/L increase in plasma total cholesterol levels. However, as previously mentioned, persons who consume more than one egg a day do not have a greater relative risk for CHD than those who eat only one egg a week. There are populations that may benefit from decreasing dietary cholesterol intake such as those with diabetes who may possess an abnormality in the mechanism by which they transport cholesterol. However, the current recommendation is applied to the general population without taking individual differences into account. Furthermore, the revised guidelines only allow for eggs to be incorporated into a healthy diet if no other animal products are consumed. Because this guideline is unrealistic, it further promotes the public message that eggs should be avoided. The reality of the situation is that although egg intake has steadily declined since the original recommendations in the 1970s, CHD is still the leading cause of death in the U.S. today. Clearly, the current guidelines are not benefiting the public as a whole and may actually have negative nutritional implications.
The fact that no studies in the past decade have reported a significant relation between either egg consumption or dietary cholesterol intakes and heart disease risk is consistent with the view that the hypothesis that dietary cholesterol is a risk factor for heart disease should be dismissed. A small, statistically significant increase in the ratio of total to HDL cholesterol has little biological importance concerning heart disease risk when considered relative to those dietary and lifestyle factors that do in fact contribute to heart disease risk.
And another excellent paper the nutritional and functional roles of the egg, we will quote excerpts from the paper:
Elizabeth Applegate, PhD. Department of nutrition, University of California at Davis, Davis, California. Nutritional and Functional Roles of eggs in the Diet. Journal of the American College of nutrition, Vol. 19, No. 90005, 495S-498S (2000).
For years, eggs have been held up as a powerhouse of nutrition. This reputation has been due to eggs' exceptional nutrition profile as a nutrient-dense food containing high quality protein and a substantial amount of many essential vitamins and minerals. Unfortunately their position on the nutrition pedestal fell with the discovery that they are also a source of dietary cholesterol. The most recent scientific research not only returns eggs to their golden past, but elevates their position as a functional food and ultimately provides more reasons than ever to consume eggs.
In February 2000, scientists convened at a conference in Amelia Island, Florida, to discuss the latest research about the role of eggs in disease prevention and the promotion of health. This supplement of the Journal of the American College of nutrition (JACN) presents compelling scientific evidence about eggs' functional food attributes, reaffirms that eggs have a minimal effect on blood cholesterol levels and presents new research on the contribution of eggs to the American diet. For health professionals, this issue provides a new scientifically based viewpoint on eggs and their role in health and nutrition, a viewpoint that should be imparted to all consumers in an effort to ensure optimal health and well-being.
Information about cholesterol and heart disease began being publicized in the 1960s, with the first observations linking diet to heart disease. In the early 1970s, the American heart Association published its first recommendations on diet. Among them was a suggested limitation on dietary cholesterol to less than 300 mg/day. High cholesterol foods like eggs and shellfish were highlighted as foods to minimize in the diet. Consumers have been and continue to be concerned about cholesterol in foods, in good measure a result of 40 years of communication regarding high cholesterol foods, blood cholesterol levels and heart disease. What consumers may not realize is how little effect changes in dietary cholesterol intake have on blood levels.
Recent studies have cast further doubt on the relationship between dietary cholesterol and heart disease. Steven Kritchevsky and David Kritchevsky review recent epidemiological studies relating dietary factors to incidence of heart disease. The authors note that research has not established a significant independent relationship between dietary cholesterol and LDL or total serum cholesterol levels, incidence of heart disease or heart disease deaths. Furthermore, data fail to show a relationship between egg consumption and either serum cholesterol levels or heart disease incidence. Recent research using an endpoint of heart disease and stroke rather than serum cholesterol levels calls into question the need to limit a high cholesterol food like eggs. In their analysis of data from prospective epidemiological studies, Hu et al.  found that consumption of up to one egg a day was not related to heart disease or stroke risk. The papers in this issue, along with emerging research, support the importance of educating patients and consumers on changing views in the area of diet and disease prevention, in light of emerging research and new findings on the absence of health risks from dietary cholesterol and new studies showing health benefits from egg consumption.
And towards the end of the paper:
The time has come to change consumer attitudes about how eggs can contribute to overall health rather than incorrectly positioning them as a risk factor in heart disease. Scientists, medical professionals and communicators are challenged with changing consumer attitudes and behaviors about eggs. Beliefs and behaviors can stem from cultural influences rather than from nutrition science. For example, many consumers link eating spinach to strength because a cartoon sailor's muscles popped up every time he ate a can of spinach. The association of eggs with heart disease stemmed from observational studies, but its perpetuation is driven by more culture and public health than by science. The egg is the latest in a long line of foods to evoke consumer fear, as noted in this issue by William Alex McIntosh. He cites the 1960s as the first time that consumers were told to limit or avoid eggs, despite a lack of research on whether eggs themselves elevated blood cholesterol. Eggs have become a symbol of the negative aspects of the American diet, and fear among the American population of eating eggs may be resulting from a lack of consensus in the scientific community and the widespread marketing of low cholesterol foods. The media have helped publicize the egg-heart disease message. McIntosh points out that news articles on eggs overwhelmingly have focused on the egg-cholesterol-heart disease connection. In contrast, home and hearth magazines mention eggs most in the context of recipes. New research findings on the functionality of eggs will allow health professionals to communicate positive messages about eggs and health to the media. The time is right to change the egg message.
A Note on egg Consumption for Diabetics
There are reports indicating that increased egg consumption in diabetics is associated with increase in risk of cardiovascular disease. We will mention these papers here. This means that diabetics should not eat eggs in large amounts, though it does not mean they have to abandon eggs in the diet.
Hu FB, Stampfer MJ, Rimm EB, Manson JE, Ascherio A, Colditz GA, Rosner BA, Spiegelman D, Speizer FE, Sacks FM, Hennekens CH, Willett WC. Department of nutrition, Harvard School of Public health, Boston, Mass 02115, USA. A prospective study of egg consumption and risk of cardiovascular disease in men and women. JAMA. 1999 Apr 21;281(15):1387-94.
CONTEXT: Reduction in egg consumption has been widely recommended to lower blood cholesterol levels and prevent coronary heart disease (CHD). Epidemiologic studies on egg consumption and risk of CHD are sparse. OBJECTIVE: To examine the association between egg consumption and risk of CHD and stroke in men and women. DESIGN AND SETTING: Two prospective cohort studies, the health Professionals Follow-up Study (1986-1994) and the Nurses' health Study (1980-1994). PARTICIPANTS: A total of 37851 men aged 40 to 75 years at study outset and 80082 women aged 34 to 59 years at study outset, free of cardiovascular disease, diabetes, hypercholesterolemia, or cancer. MAIN OUTCOME MEASURES: Incident nonfatal myocardial infarction, fatal CHD, and stroke corresponding to daily egg consumption as determined by a food-frequency questionnaire. RESULTS: We documented 866 incident cases of CHD and 258 incident cases of stroke in men during 8 years of follow-up and 939 incident cases of CHD and 563 incident cases of stroke in women during 14 years of follow-up. After adjustment for age, smoking, and other potential CHD risk factors, we found no evidence of an overall significant association between egg consumption and risk of CHD or stroke in either men or women. The relative risks (RRs) of CHD across categories of intake were less than 1 per week (1.0), 1 per week (1.06), 2 to 4 per week (1.12), 5 to 6 per week (0.90), and > or =1 per day (1.08) (P for trend = .75) for men; and less than 1 per week (1.0), 1 per week (0.82), 2 to 4 per week (0.99), 5 to 6 per week (0.95), and > or =1 per day (0.82) (P for trend = .95) for women. In subgroup analyses, higher egg consumption appeared to be associated with increased risk of CHD only among diabetic subjects (RR of CHD comparing more than 1 egg per day with less than 1 egg per week among diabetic men, 2.02 [95% confidence interval, 1.05-3.87; P for trend = .04], and among diabetic women, 1.49 [0.88-2.52; P for trend = .008]). CONCLUSIONS: These findings suggest that consumption of up to 1 egg per day is unlikely to have substantial overall impact on the risk of CHD or stroke among healthy men and women. The apparent increased risk of CHD associated with higher egg consumption among diabetic participants warrants further research.
Qureshi AI, Suri FK, Ahmed S, Nasar A, Divani AA, Kirmani JF. Epidemiological and Outcomes Research Division, Zeenat Qureshi stroke Research Center, Department of Neurology and Neurosciences, University of medicine and Dentistry of New Jersey, Newark, NJ, USA. Regular egg consumption does not increase the risk of stroke and cardiovascular diseases. Med Sci Monit. 2007 Jan;13(1):CR1-8
BACKGROUND: We performed this study to examine the association between egg consumption and risk of cardiovascular diseases and mortality in a nationally representative cohort of 9734 adults aged 25 to 74 years. MATERIAL/METHODS: egg consumption was categorized into no or less than 1 egg, 1 to 6 eggs, or greater than 6 eggs per week. Cox proportional hazards analysis was used to identify the relative risk (RR) of incident stroke, ischemic stroke, coronary artery disease and mortality over a 20-year follow-up in all participants and subsequently in diabetic participants. RESULTS: After adjusting for differences in age, gender, race, serum cholesterol level, body mass index, diabetes mellitus, systolic blood pressure, educational status and cigarette smoking, no significant difference was observed between persons who consumed greater than 6 eggs per week compared to those who consume none or less than 1 egg per week in regards to any stroke (RR, 0.9; 95% confidence interval (CI), 0.7 to 1.1), ischemic stroke (RR, 0.9; 95% CI, 0.7 to 1.1), or coronary artery disease (RR, 1.1; 95% CI, 0.9 to 1.3). In subgroup analysis among diabetics, consumption of greater than 6 eggs per week was associated with an increased risk of coronary artery disease (RR 2.0, 95% CI 1.0-3.8). CONCLUSIONS: Consumption of greater than 6 eggs per week (average of 1 egg or greater per day) does not increase the risk of stroke and ischemic stroke. The increased risk of coronary artery disease associated with higher egg consumption among diabetics warrants further investigations.
The above studies show that in normal people egg consumption has no significant effect on risk of coronary heart disease. For diabetics however, egg consumption of more than six a week was associated with an increased risk of coronary heart disease. So in light of the above studies which state that further research is still warranted, it may be prudent for diabetics to limit egg intake - bearing in mind that eggs do not have to be completely eliminated from the diet.
Eggs were always good nutrition, still are and will remain so. Make sure your eggs are from chickens that are free range or organic. Its best to get your eggs from a local farm than from a supermarket, supermarket eggs, in our opinion, are just tasteless. The healthiest way to have your egg is to boil it, half or full.