Table 1.
Summary of epidemiological evidence regarding egg consumption, cardiovascular disease, and incidence of diabetes.
| Study | Design | Association between Egg Consumption and Cardiovascular Disease | Association between Egg Consumption and Incidence of Diabetes |
|---|---|---|---|
| Framingham Study and Offspring study [8,9] | 24 year follow up of 912 and a prospective cohort of 2879 American participants | No association between egg intake and subsequent development of CHD | Intake of eggs associated with incidence of type 2 diabetes with some dietary pattern scores |
| Italian case-control study [10] | 287 cases with AMI and 649 controls, Italian women, conducted over 5 years | No association between egg consumption of greater than 2 eggs/week and nonfatal myocardial infarction | Not reported |
| Finnish Study [11] | 14 year follow up of 5133 Finnish men and women aged 30–69 years | No difference in egg consumption between individuals who developed fatal coronary heart disease and those who did not | Not reported |
| Oxford Vegetarian Study [12] | 14 year follow up of 11,140 English vegetarians and meat eating participants | >6 eggs/week associated with increased mortality from ischemic heart disease | Not reported |
| Adventist Health Study [13] | 6 year follow up of 34,192 vegetarian and non-vegetarian American Seventh Day Adventists |
Consuming >2 eggs/week presents no difference in risk of developing CHD compared to consuming <1 eggs/week | Not reported |
| Nurses Health [14] | 14 year follow up of 80,082 American women aged 39–54 years | No association between consumption of up to 1 egg/day and risk of CHD or stroke; higher egg consumption was associated with increased CHD risk in people with diabetes | Not reported |
| Health Professionals Follow-up [14] | 14 year follow up of 37,851 American men aged 40–75 years | No association between consumption of up to 1 egg/day and risk of CHD or stroke; higher egg consumption was associated with increased CHD risk in people with diabetes | Not reported |
| Japanese case-control study [15] | 660 cases with AMI and 1277 controls, Japanese men and women aged 40–79 years | No association between egg intakes up to 4 or more/week and incidence of AMI | Not reported |
| NIPPON DATA80 [16] | 14 year follow up of 5186 women and 4077 men, all Japanese aged 30 years and over | No effect of egg consumption on risk of fatal CHD events, stroke and cancer in men or women consuming ≥2 eggs/day; increased risk of all cause mortality in women for ≥1 egg/day | Not reported |
| Japan Public Health Centre-based study [17] | 21 year follow up of 90,735 Japanese male and female participants aged 40–69 years | Total cholesterol levels were significantly related to an increased risk of CHD, however consumption of eggs almost daily was not associated with CHD risk in middle-aged Japanese men and women | Not reported |
| Greek EPIC diabetic subgroup [18] | 11 year follow up of 1013 Greek adults with diabetes | Positive association with increased egg consumption and cardiovascular mortality in people with diabetes | Not reported |
| NHANES I [19] | 20 year follow up of 9734 American adults aged 25 to 74 years | No significant difference between consuming >6 eggs/week compared to <1 egg/week in any stroke, ischemic stroke or coronary artery disease; consumption of >6 eggs/week was associated with an increased risk of CHD in people with diabetes | Not reported |
| Physician’s Health [20,21,22] | 20 year follow up of 21,327 American male participants aged 40 years and over and 36,295 American women aged 45 years | Egg consumption did not increase CVD risk, but consumption of ≥7/week was associated with a 23% increased risk of all cause mortality and in a separate study of the same cohort, a 28% increase risk of heart failure; consumption of ≤6 eggs/week did not increase the risk of death from all causes | Men who ate 5–6 eggs/week had a 46% higher risk of developing type 2 diabetes than no eggs, and 58% higher for ≥7 eggs/week; women who ate 2–4 eggs a week had a 19% higher risk, and 77% higher for ≥7 eggs/week. In both groups, there was a significantly increased risk of developing type 2 diabetes with increasing egg consumption |
| INTERHEART (A Global Case-Control Study of Risk Factors for Acute Myocardial Infarction) [23] | Global study reporting on 5761 patients who have had a heart attack and 10,646 controls free of heart disease, recruited over 4 years | Western dietary pattern (characterised by higher intakes of fried foods, salty snacks and meat) was shown to be associated with an increased risk of heart attack; no association between eggs and heart attack risk | Not reported |
| Atherosclerosis Risk in Communities (ARIC) [24] | 11 year follow up of 15,792 African American and white American men and women aged 45–64 years | 23% increased risk of heart failure for each extra serving of eggs/day, up to 7 eggs/week | Not reported |
| Insulin Resistance Atherosclerosis Study [25] | Prospective cohort of 880 American individuals with normal glucose tolerance or impaired glucose tolerance | Not reported | High intake of a dietary pattern that included eggs (as well as red meat, low fibre bread and cereal, dried beans, fried potatoes, tomato, vegetables, cheese and cottage cheese, and low in wine) was associated with developing type 2 diabetes |
| Cardiovascular health study [26] | Prospective study of 3898 American older adults (>65 years) followed for an average of 11.3 years | Not reported | There was no association between egg consumption or dietary cholesterol intake and risk of developing type 2 diabetes |
| Health ABC Study [27] | 9 year follow up of 1941 70–79 years old Americans | Dietary cholesterol and consumption of ≥3 eggs/week was associated with increased CVD risk only in older adults with type 2 diabetes (but not in those without type 2 diabetes) | Not reported |
| NHANES III [28] | 9 year follow up of 20,050 American adults (17 years and over) | No association between egg intake (>7/week compared to <1/week) and CHD mortality | Not reported |
| Chinese cohort study [29] | Data from 2849 Chinese adults (20 years and over) | Not reported | Egg consumption was significantly and positively associated with diabetes risk. The OR of diabetes associated with egg consumption <2/week, 2–6/week, and ≥1/day in the total sample were 1.00, 1.75, 2.28 respectively. These associations were stronger in women compared to men |
| The SUN Project [30] | 6 year follow up of 14,185 Mediterranean university students | No association between egg consumption and the incidence of CVD for the highest (>4 eggs/week) versus the lowest (<1 egg/week) category of egg consumption | Not reported |
| Case-control study [31] | 234 Lithuanians aged 35–86 years with a newly confirmed diagnosis of type 2 diabetes according to WHO criteria, and 468 controls | Not reported | Participants who consumed >5 eggs/week had a higher risk (threefold) of type 2 diabetes than those who consumed <1 egg/week |
| Malmo Diet and Cancer Cohort [32] | Prospective cohort including 27,140 Swedish participants (45–74 years) during a 12 year follow up | Not reported | Highest quintiles of egg intake associated with increased risk of developing type 2 diabetes |
| Mediterranean cohort—the SUN project [33] | Prospective cohort of 15,956 participants from Spanish population (average age 38.5 years) during 6.6 years (median) follow up | Not reported | Egg consumption was not associated with the development of diabetes, comparing the highest (>4 eggs/week) with the lowest (<1 egg/week) quartile of egg consumption |
| The Northern Manhattan Study [34] | 1429 American adults with carotid ultrasounds followed for 11 years | Egg consumption was inversely associated with carotid intima media thickness. For every additional egg consumed/week, risk of plaque decreased by 11% | Not reported |
| The Kuopio Ischaemic Heart Disease Risk Factor Study [35] | 2332 men from Finnish population (42–60 years) during 19.3 years follow-up | Not reported | Higher egg intake was associated with a 38% lower risk of developing type 2 diabetes compared to those in the lowest group of egg intake |
| Meta-Analysis/Systematic Review regarding egg consumption, cardiovascular disease, and incidence of diabetes | |||
| Cardiovascular diseases and diabetes meta-analysis [36] | 14 studies (320,778 participants):11 prospective, 1 case-control and 2 cross-sectional studies. Sample size ranged from 488 to 117,943. Follow-up time from 6.1 to 20 years | Positive dose-response association between egg consumption and risk of CVD. A 19% increased risk of CVD in highest egg consumption compared to lowest egg intake. A sub group (participants with diabetes) found to have a further increased risk of CVD (RR 1.83) | There was a dose-response positive association between egg consumption and risk of diabetes |
| Dose-response meta-analysis of prospective cohort studies [37] | 8 articles with 17 reports (9 for CHD and 8 for stroke) | No significant association found between egg consumption up to 1 egg/day and risk of CHD or stroke. In a subgroup analysis of people with diabetes, higher egg consumption (up to 1 egg/day) associated with a higher risk of CHD but lower risk of haemorrhagic stroke | Not reported |
| Cardiovascular disease and diabetes systematic review and meta-analysis [38] | 22 independent cohorts from 16 studies. Number of participants ranged from 1600 to 90,735. Follow-up time ranged from 5.8 to 20 years | Consuming ≥1 egg/day was not associated with risk of overall CVD, ischemic heart disease, stroke or mortality. In a subgroup population (people with diabetes), those who ate eggs >once a day were 1.69 times more likely to develop CVD co-morbidity | Those who ate ≥1 egg/day (compared to those who never ate eggs) were 42% more likely to develop type 2 diabetes |
| Tran et al. systematic review [39] | 8 epidemiological studies that examined the risk of developing type 2 diabetes mellitus. 6 of the studies evaluated egg consumption, whilst 2 of the studies evaluated dietary patterns that included eggs | Not reported | 4 of the 8 studies found a significant association between diabetes risk and egg consumption. |
Abbreviations: ABC, ageing and body composition; AMI, acute myocardial infarction; ARIC, atherosclerosis risk in communities; CHD, coronary heart disease; CVD, cardiovascular disease; EPIC, European prospective investigation into cancer and nutrition; NHANES, national health and nutrition examination survey; OR, odds ratio; RR, relative risk.