One large egg has 72 calories and 6.3 g of protein. On our scale that protein scores 100 out of 100 for essential amino acids, with none in short supply.
The same egg holds 147 mg of choline, 27% of the Daily Value (the US label target), and 28% of the daily selenium. In a trial, blood choline rose after whole eggs but not after a yolk-free substitute. So the yolk is where much of the choline sits.
The yolk also carries lutein and zeaxanthin, pigments that build up in the retina. A large egg has 252 µg (micrograms), and in a trial one egg a day raised blood levels of both in older adults. The same yolk holds 186 mg of cholesterol, 62% of the Daily Value. That is why eggs have sat at the center of heart-health arguments for decades.
The US Dietary Guidelines of 2010 capped dietary cholesterol at 300 mg a day. The 2015 to 2020 edition left that cap out, while still advising people to eat as little dietary cholesterol as possible.
Cooking matters too. In a small trial, 90.9% of cooked egg protein was digested, against 51.3% of raw egg protein.
Health benefits of eggs
The top findings from 31 studies, strongest evidence first
What the stars mean
- Strong. Several randomized trials, pooled in a meta-analysis, point the same way, or regulators (FDA or EFSA) have approved the claim.
- Moderate. Good randomized trials support it, but there are fewer of them, or their results vary.
- Limited. Small, short or single trials, or mixed results. Promising, but it needs confirmation.
Population and lab studies get no stars: they show a link or a mechanism, not proof.
How we rate evidence →- ★★★Raised both LDL and HDL cholesterolAcross 28 trials, LDL rose a little (5.55 mg/dL) and HDL too (2.13 mg/dL), leaving their ratio unchanged. A third analysis, in healthy people, found the ratio did rise by 0.14.
- ★★No worse cholesterol or blood sugar in diabetesIn 140 adults with prediabetes or type 2 diabetes, 2 eggs a day for 3 months did not change LDL cholesterol or blood sugar control. A 12-month follow-up found no adverse changes on a high-egg diet.
- ★★Less egg allergy when babies eat egg earlyBabies given egg at 4 to 6 months had less egg allergy across 5 trials, with 24 fewer cases per 1000 children. In babies with eczema in Japan, heated egg powder cut egg allergy from 38% to 8%, though hospital admissions were more common (10% against none).
- ★★Mixed results for babies’ growthOne egg a day for 6 months cut stunting by 47% in babies in Ecuador. In rural Malawi, it did not raise length-for-age, a growth measure.
- ★★Raised eye pigment and blood luteinAcross 5 trials, eating eggs raised macular pigment, which filters light in the retina, by 0.037. Blood lutein rose by 0.150 µmol/L.
All 31 studies, strongest evidence first
Eggs raised LDL cholesterol but not the LDL to HDL ratio
This meta-analysis pooled 66 randomized trials with 3,185 people. Total cholesterol rose, HDL cholesterol rose too, and triglycerides did not change significantly. The authors say more than one egg a day for under 12 weeks may raise some blood lipids. One egg a day can be safe, they add.
Eggs raised both LDL and HDL cholesterol, leaving their ratio unchanged
This meta-analysis pooled 28 randomized trials published after 2000, comparing egg eaters with people who ate few or no eggs. LDL rose 5.55 mg/dL, HDL 2.13 mg/dL and total cholesterol 5.60 mg/dL, while triglycerides did not change. The number of eggs a day and the length of the trial did not predict the change. Results varied with study design and with how strongly people respond to dietary cholesterol.
In healthy people, more eggs raised LDL cholesterol by 8.14 mg/dL
This meta-analysis pooled 17 randomized trials in healthy people, without other treatments. Eggs also raised the LDL to HDL ratio by 0.14, unlike in the two analyses above. The rise looked larger in trials that lasted longer than two months, and the authors call for long-term trials.
2 daily eggs did not worsen cholesterol or blood sugar in diabetes
The DIABEGG trial randomized 140 overweight or obese adults with prediabetes or type 2 diabetes. For 3 months they ate 2 eggs a day, 6 days a week, or fewer than 2 eggs a week. HDL cholesterol differed by +0.02 mmol/L, and total cholesterol, LDL, triglycerides and blood sugar control did not differ. The egg group reported less hunger after breakfast, and the Australian Egg Corporation is listed among the funders.
A high-egg diet caused no adverse changes over 12 months in diabetes
This follow-up of the DIABEGG trial covered 128 people with prediabetes or type 2 diabetes. They ate a weight-loss diet for 3 months, with 12 or more eggs a week in the high-egg group, and were followed for 6 more. Cholesterol, blood sugar, inflammation and oxidative stress markers did not differ, and weight loss was the same in both groups (3.1 kg). The authors say a healthy diet with more eggs than some national guidelines allow may be safe.
6 to 12 eggs weekly left cholesterol, glucose and CRP unchanged
This systematic review covered 10 articles from 6 randomized trials in people with or at risk of type 2 diabetes. The trials compared eggs with a no-egg or low-egg diet (under 2 eggs a week). HDL cholesterol rose in 4 of the 6 trials. The authors say differences between the trials prevent firm conclusions.
Babies given egg at 4 to 6 months had less egg allergy
This systematic review and meta-analysis pooled 5 trials with 1915 infants. The risk ratio was 0.56: for a population with 5.4% egg allergy, that is 24 fewer cases per 1000 children. The authors rate the certainty as moderate and note limits in precision and in how closely the trials matched real feeding. Early peanut introduction also lowered peanut allergy.
In eczema, heated egg powder cut egg allergy from 38% to 8%
In this double-blind trial in Japan (PETIT), babies with eczema got heated egg powder or a placebo (dummy powder), alongside strict eczema treatment. The dose was 50 mg a day from 6 months and 250 mg a day from 9 months; egg allergy was measured by age 1. It was stopped early after an interim look at 100 babies, and hospital admissions were more common with egg (10% against none). The funders were the Japanese health ministry and a national child health center.
Early allergenic foods did not significantly lower food allergy overall
The EAT trial randomized 1303 exclusively breast-fed UK infants to six allergenic foods, including cooked egg, from 3 months, or standard feeding. In the full analysis, food allergy was 5.6% against 7.1%, not a significant difference. Among infants who stuck to the plan (per-protocol), egg allergy was 1.4% in the early group and 5.5% in the standard group. Eating about 2 g of egg-white protein a week went with less egg allergy. The authors say introducing all six foods early was not easy but was safe, and the Food Standards Agency was among the funders.
One egg a day cut stunting by 47% in babies in Ecuador
The Lulun Project randomized babies aged 6 to 9 months, with 83 getting an egg a day for 6 months and 80 not. Length-for-age z score, a growth measure, rose by 0.63, and caregivers reported no allergic reactions. The Mathile Institute, a nonprofit, funded the trial and two authors worked there at the time. It says it has no stake in the result.
In rural Malawi, one egg a day did not raise length-for-age
This randomized trial gave 660 babies aged 6 to 9 months an egg a day for 6 months. Head circumference for age rose 0.18, and length gained only in children of better-educated mothers. Only 14% were stunted at the start, and the authors think a diet already rich in animal foods may have limited the effect. The Bill and Melinda Gates Foundation funded it.
Across 5 trials, eating eggs raised macular pigment and blood lutein
This meta-analysis pooled 296 people. Macular pigment optical density, a measure of the pigment that filters light in the retina, rose by 0.037, and serum lutein by 0.150 µmol/L. A higher pigment level may lower the risk of age-related macular degeneration, an eye disease of aging. The authors say more trials are needed.
Pasteurized raw egg powder in eczema lowered egg allergy, but not significantly
In this double-blind trial, 49 babies with eczema took a daily teaspoon of pasteurized raw egg powder and 37 took rice powder. Given from 4 to 8 months, egg lowered egg allergy at 12 months from 51% to 33%, but the drop was not significant. Of those given egg, 31% had an allergic reaction and stopped. The authors warn that 36% of the infants already had egg-specific antibodies before eating egg, so first exposure needs care in babies with eczema.
2 daily eggs in a weight-loss diet did not raise LDL cholesterol
This randomized trial put 65 adults with type 2 diabetes or impaired glucose tolerance on a weight-loss diet for 12 weeks. The egg diet (2 eggs a day) gave 590 mg of cholesterol a day, against 213 mg for a diet with lean meat instead. Both groups lost about 6 kg, and blood sugar and blood pressure improved in both. HDL rose 0.02 mmol/L on eggs and fell 0.07 on the other diet.
Whole eggs beat a yolk-free substitute on HDL and insulin resistance
In this single-blind trial, people with metabolic syndrome ate 3 whole eggs a day (20 people) or a yolk-free substitute (17) for 12 weeks. Both groups were on a moderately carbohydrate-restricted diet. Triglycerides and small LDL particles fell in both groups. It was small and short.
2 eggs daily did not harm artery function; a substitute improved it
In this randomized crossover trial, 40 adults with total cholesterol around 244 mg/dL ate eggs or an egg substitute, 6 weeks each. Flow-mediated dilation, a test of how well arteries widen, changed 1.0% on the substitute and −0.1% on eggs. The substitute also lowered LDL by 14 mg/dL, against 2 mg/dL on eggs. The Egg Nutrition Center and the CDC funded the study.
One egg daily raised lutein 26% and zeaxanthin 38% in older adults
In this randomized crossover trial, 33 people over 60 ate an egg or an egg substitute a day for 5 weeks. The rises were in serum (blood) levels, and total, LDL and HDL cholesterol and triglycerides did not change. The authors note that egg yolk is a rich source of both pigments in the American diet.
Scrambled eggs raised carotenoid absorption from a salad 3 to 8 times
In this randomized crossover trial, 16 healthy young men ate a raw vegetable salad with 3 scrambled eggs. Lutein and zeaxanthin absorption rose 4 to 5 times, and 1.5 eggs gave a smaller rise. The American Egg Board-Egg Nutrition Center, the NIH and Purdue University funded the study. The paper says the board was not involved in the design, analysis or interpretation.
Cooked egg protein was digested 90.9% against 51.3% for raw egg protein
Five people with an ileostomy ate 25 g of labeled egg protein, cooked and raw. An ileostomy lets the small intestine empty outside the body, so researchers could measure what left it. The authors say heat raises how much egg protein is absorbed. It is a very small study.
2 eggs a day raised blood choline and betaine but not TMAO
In this randomized crossover trial, 20 overweight postmenopausal women with mildly high cholesterol ate eggs or a yolk-free substitute for 4 weeks. TMAO is a gut-bacteria compound linked to heart disease. Gut bacteria composition did not change either. The Egg Nutrition Center and the USDA are listed among the funders.
Mothers on 930 mg choline had babies with faster information processing
This controlled-feeding trial had 13 women in each group in their third trimester; the comparison group got 480 mg of choline a day. Researchers tested 24 infants at 4, 7, 10 and 13 months. The extra choline was a supplement within a controlled diet, so it does not show what eggs do. The funders included the Egg Nutrition Center, the Beef Checkoff and the USDA.
Dieters eating egg breakfasts lost 65% more weight than bagel eaters
This trial put 152 overweight or obese adults on egg or bagel breakfasts for 8 weeks. On a calorie-cut diet, the egg group lost 2.63 kg against 1.59 kg, and BMI fell 61% more. Without a calorie-cut diet, the egg breakfast did not cause weight loss. The American Egg Board funded the study.
Whole eggs built more muscle protein than egg whites after weight training
In this crossover trial, 10 resistance-trained men ate eggs or egg whites, each with 18 g of protein. Egg whites were digested faster, but total amino acid availability was similar. It measured a short-term tracer marker in a very small group, not strength.
Each extra half egg daily went with 6% higher heart disease risk
This pooled analysis of 6 US cohorts followed 29,615 adults for a median of 17.5 years, with 5400 heart disease events and 6132 deaths. The same amount also went with an 8% higher risk of death. After adjusting for dietary cholesterol, egg intake alone was no longer linked to risk (hazard ratio 0.99 for heart disease). Diet was self-reported, and a link is not proof of cause.
An egg a day was not linked to heart disease risk
The Nurses’ Health Studies and the Health Professionals Follow-up Study, 3 US cohorts, followed people for up to 32 years. People who ate more eggs also had a higher BMI and ate more red meat. A meta-analysis pooled 33 risk estimates: the relative risk was 0.98 overall, lower in Asian cohorts (0.92) and not different in US or European ones. The funders were the NIH and the Canadian Institutes of Health Research.
7 or more eggs a week was not linked to heart disease
The PURE study and two trial cohorts covered about 177,000 people in 50 countries, including 146,011 from 21 countries in PURE. Compared with under 1 egg a week, the hazard ratio was 0.92 for major cardiovascular disease and 1.04 for death, neither a clear link. Blood lipids did not differ, and diet came from food questionnaires.
Each extra half egg daily went with 7% higher risk of dying
This US cohort followed 521,120 adults aged 50 to 71 for a median of 16 years, with 129,328 deaths. Each extra 300 mg of dietary cholesterol a day went with 19% higher all-cause mortality, and cholesterol explained much of the egg link. People who ate egg whites or substitutes had lower mortality. The authors note self-reported diet and possible residual confounding, other differences they could not fully adjust for.
Chinese daily egg eaters had a lower risk of cardiovascular disease
The China Kadoorie Biobank of 0.5 million Chinese adults included 461,213 free of heart disease, cancer and diabetes at the start. Daily eaters averaged 0.76 eggs a day and had 0.89 times the risk of cardiovascular disease. Risk of hemorrhagic stroke (bleeding in the brain) was lower too (0.74), and daily eaters had an 18% lower risk of cardiovascular death. Egg eaters may differ in other ways despite the adjustments.
An extra daily egg was not linked to heart disease or stroke
This dose-response meta-analysis of cohort studies pooled 8 articles with 17 reports. For each extra egg a day, the relative risk was 0.99 for coronary heart disease and 0.91 for stroke. In people with diabetes, the highest egg intake went with a higher risk of coronary heart disease (1.54). Overall, the highest intake went with a 25% lower risk of hemorrhagic stroke, and the authors call both findings for further study.
A review could not settle whether dietary cholesterol raises heart disease risk
This review of 40 studies pooled 17 cohorts (361,923 people) and 19 trials (632 people) from 1979 to 2013. In trials, dietary cholesterol raised total cholesterol by 11.2 mg/dL and LDL by 6.7 mg/dL. The cohorts did not link it to coronary disease, and the authors found the studies too mixed to conclude. The American Egg Board-Egg Nutrition Center and the USDA are listed among the funders.
Per daily egg, 14% higher diabetes risk, only in US cohorts
These 3 US cohorts recorded 20,514 cases of type 2 diabetes. A meta-analysis of 16 cohort studies from around the world found a relative risk of 1.07 for each egg a day, no clear link. It was 1.18 in US studies, 0.99 in European and 0.82 in Asian ones. The authors say the difference between regions needs study.
Who should be careful with eggs
Most people can eat eggs freely. Take a little care if one of these applies:
- Raw or runny eggs. Salmonella, a food-poisoning bacterium, is the concern. In the UK, the FSA (Food Standards Agency) says eggs with the British Lion mark can be eaten raw or runny by vulnerable groups. That covers babies, young children, pregnant people and older people, except those who are severely immunocompromised. The NHS says other eggs should be cooked until the white and yolk are solid. In the US, the FDA lists children, older adults, pregnant women and people with weakened immune systems as higher risk. It advises cooking eggs until the yolk and white are firm.
- Egg allergy in babies. The NHS and the US Dietary Guidelines say to offer egg along with other first foods from about 6 months rather than delay it. If your baby has eczema, another food allergy or a family history of allergy, talk to a GP or health visitor first. Many children outgrow egg allergy, but some do not.
- High LDL cholesterol or type 2 diabetes. Trials show a small rise in LDL cholesterol. Cohorts disagree on diabetes risk, with a higher risk in US cohorts but not in European or Asian ones. The American Heart Association advises focusing on healthy dietary patterns, which are relatively low in cholesterol. Ask your care team how many eggs fit.
How to choose, store and eat eggs
- Cooked: in 5 people with an ileostomy, 90.9% of cooked egg protein was digested against 51.3% of raw.
- With vegetables: 3 scrambled eggs raised absorption of carotenoids from a raw salad 3 to 8 times in 16 men.
- Whole, not only whites: after weight training, whole eggs stimulated more muscle protein building than egg whites in 10 men. Blood choline also rose with whole eggs but not with a yolk-free substitute.
Keep eggs in their carton in the fridge at 40°F or below. The FDA says raw shell eggs keep about 3 weeks for best quality and hard-cooked eggs about 1 week. In the UK, look for the British Lion mark on the shell and the box.
Residues are no reason to skip eggs. In 2016 the USDA Pesticide Data Program tested 294 chicken egg samples and found one residue. It was cyromazine, in two samples (0.7%), far below the legal tolerance.
Sources
- Home food fact checker. Food Standards Agency, via GOV.UK.
- Foods to avoid giving babies and young children. NHS.
- Food allergies in babies and young children. NHS.
- What you need to know about egg safety. US Food and Drug Administration.
- Dietary Guidelines for Americans 2020 to 2025: infants and toddlers. USDA and HHS.
- Carson JAS, Lichtenstein AH, Anderson CAM, et al. Dietary cholesterol and cardiovascular risk: a science advisory from the American Heart Association. Circulation. 2020.
- Evenepoel P, Geypens B, Luypaerts A, et al. Digestibility of cooked and raw egg protein in humans as assessed by stable isotope techniques. J Nutr. 1998.
- Kim JE, Gordon SL, Ferruzzi MG, Campbell WW. Effects of egg consumption on carotenoid absorption from co-consumed, raw vegetables. Am J Clin Nutr. 2015.
- van Vliet S, Shy EL, Abou Sawan S, et al. Consumption of whole eggs promotes greater stimulation of postexercise muscle protein synthesis than consumption of isonitrogenous amounts of egg whites in young men. Am J Clin Nutr. 2017.
- Zhu C, Sawrey-Kubicek L, Bardagjy AS, et al. Whole egg consumption increases plasma choline and betaine without affecting TMAO levels or gut microbiome in overweight postmenopausal women. Nutr Res. 2020.
- Pesticide Data Program annual summary, calendar year 2016. USDA Agricultural Marketing Service.
History of eggs
Every chicken egg on the table traces back to a jungle bird. A study of 863 genomes found that domestic chickens come mainly from one red junglefowl subspecies, Gallus gallus spadiceus. It lives today in southwestern China, northern Thailand and Myanmar. After domestication, chickens were carried across Southeast and South Asia and interbred with other junglefowl.
Chickens reached Sumer and Egypt by about 1500 BCE and Greece around 800 BCE, where quail had been the main source of eggs. Roman meals often began with an egg course, and medieval Europe forbade eggs during Lent.
Breeding changed the hen. Birds that once laid about a dozen eggs a year now lay more than 300 a year, all year round. The egg carton was invented in 1911 in Smithers, British Columbia.
Eggs have also been a political topic. In December 1988 the British health minister Edwina Currie said most egg production in the country was affected by salmonella. She resigned that month.
Egg sales reportedly fell by 60%, and about four million hens were slaughtered. In 2016 the UK’s expert committee judged the risk from eggs made under assurance schemes such as the Lion Code to be very low. In 2017 the FSA changed its advice so that vulnerable groups could eat raw or runny eggs from those schemes.
Cholesterol had its own arc. The 2010 US Dietary Guidelines capped dietary cholesterol at 300 mg a day. The 2015 to 2020 edition dropped the cap while advising people to eat as little dietary cholesterol as possible. In 2020 an American Heart Association advisory said guidance should focus on healthy dietary patterns, not a single cholesterol target.
Sources
- Wang MS, Thakur M, Peng MS, et al. 863 genomes reveal the origin and domestication of chicken. Cell Res. 2020.
- Egg as food. Wikipedia.
- Edwina Currie. Wikipedia.
- Lewis E, Cohen V, Evans C, Gherman I. Salmonella risk profile of UK-produced hen shell eggs: executive summary. Food Standards Agency. 2023.
- 2015 to 2020 Dietary Guidelines for Americans. USDA and HHS.
- Carson JAS, Lichtenstein AH, Anderson CAM, et al. Dietary cholesterol and cardiovascular risk: a science advisory from the American Heart Association. Circulation. 2020.
Frequently asked questions about eggs
Are eggs good for you?
For most people, yes. One large egg has 72 calories, 6.3 g of protein, 147 mg of choline (27% of the Daily Value) and 28% of the daily selenium. Cohorts disagree on heart disease: one US analysis found 6% higher risk per half egg a day, a pooled analysis no link (relative risk 0.98). A Chinese cohort found a lower risk (hazard ratio 0.89), but these are links, not proof, and nothing is settled.
How many eggs can you eat a day?
No study here sets a safe number: a BMJ analysis found no link between up to one egg a day and heart disease. The PURE study found none at 7 or more a week. Trials used 2 eggs a day for 3 months in diabetes and 3 whole eggs a day for 12 weeks in metabolic syndrome. If you have high LDL cholesterol or diabetes, ask your care team.
Do eggs raise cholesterol?
A little: a meta-analysis of 28 trials found eggs raised LDL by 5.55 mg/dL and HDL by 2.13 mg/dL. The ratio did not change in those trials, but in one of 17 trials LDL rose 8.14 mg/dL and the ratio 0.14. One large egg has 186 mg of cholesterol, 62% of the Daily Value. The US guidelines dropped their 300 mg cap in the 2015 edition but still advise eating as little dietary cholesterol as possible.
Is it safe to eat raw or runny eggs?
It depends on the egg and on you. In the UK, the FSA says Lion-marked eggs can be eaten raw or runny by babies, young children, pregnant people and older people. Other eggs should be cooked until the white and yolk are solid. In the US, the FDA advises cooking eggs until the yolk and white are firm, and pasteurized eggs for dishes served raw. Raw egg protein is also less digestible: 51.3% against 90.9% for cooked.
Are brown eggs healthier than white eggs?
No study here compares them. Shell color comes from pigment the hen deposits and varies with the breed. Reference works describe it as largely cosmetic, with no effect on quality or taste. The nutrition numbers on this page are for eggs in general.
Are eggs OK for people with diabetes?
They can fit, but the evidence is mixed. In the DIABEGG trial of 140 people, 2 eggs a day for 3 months did not worsen cholesterol or blood sugar control. The Australian Egg Corporation is listed among its funders. In US cohorts, each egg a day went with 14% higher risk of type 2 diabetes, unlike European and Asian cohorts. Check portions with your care team.
When can babies eat eggs?
From about 6 months, along with other first foods, according to the NHS and the US Dietary Guidelines. A meta-analysis of 5 trials found less egg allergy in babies who first ate egg at 4 to 6 months (risk ratio 0.56). In babies with eczema, a Japanese trial cut egg allergy from 38% to 8% with heated egg powder. But 10% of the egg group were admitted to hospital, so talk to a GP or health visitor first.
How much protein is in an egg?
One large egg (50 g) has 6.3 g of protein, or 12.6 g per 100 g. Its protein scores 100 out of 100 for essential amino acids on our scale. About 36% of its 72 calories come from protein. After weight training, whole eggs stimulated more muscle protein building than egg whites with the same protein in 10 men.