How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Egg
Up to one egg per day is not linked to more heart attacks or strokes; in trials, it slightly raises LDL (+5.55 mg/dL) without affecting blood pressure. After resistance training, whole eggs stimulated muscle better than egg whites alone.
Benefits
- Muscle: after a resistance training session, whole eggs stimulated muscle protein synthesis more than egg whites with equal protein (18 g), in 10 trained men.
- Strength: over 12 weeks of resistance training, 3 whole eggs after each session led to greater gains in strength (knee extension, handgrip) and greater fat loss than 6 egg whites, in 30 trained young men.
- Weight loss: with a 1,000 kcal deficit diet, two eggs at breakfast led to 65% more weight loss than an equal-calorie bagel breakfast over 8 weeks (−2.63 kg vs. −1.59 kg).
- Heart: up to one egg per day is not linked to more cardiovascular disease (relative risk of 0.98 per daily extra egg, 1.7 million participants) nor coronary disease or stroke.
- Blood pressure: no effect in 15 randomized trials (748 participants), neither on systolic nor diastolic.
- Diabetes: in 140 prediabetic or type 2 diabetic people, 2 eggs per day 6 days out of 7 for 3 months changed neither cholesterol, nor triglycerides, nor blood sugar, and were more satiating after breakfast.
- LDL: within a low-saturated-fat diet, 2 eggs per day lowered LDL compared to a high-saturated-fat diet with 1 egg per week (103.6 vs. 109.3); it was the saturated fat that drove LDL, not cholesterol.
Precautions
Allergy: in atopic infants at risk with eczema, introducing eggs very gradually from 6 months reduced allergy at one year (8% vs. 38%), but under medical supervision, with 10% hospitalizations compared to none under placebo; talk to a doctor before trying. Cholesterol: in 28 trials, eating eggs increased total cholesterol by 5.60 mg/dL, LDL by 5.55 mg/dL, and HDL by 2.13 mg/dL, without changing LDL/HDL ratios or triglycerides. Cholesterol, continued: in 17 other trials, LDL rose by 8.14 mg/dL and the LDL/HDL ratio increased, especially the longer the trial lasted beyond two months. Type 2 diabetes: in diabetics, the highest egg eaters had more cardiovascular disease (relative risk of 1.69) and coronary disease (1.54) in cohorts; a 12-month trial, however, found no effect on markers. Limitations: cohorts contradict each other: one links each 50 g egg per day to more deaths (relative risk of 1.06) and cardiovascular deaths (1.09), mostly in the USA; a meta-analysis of 33 cohorts finds nothing on deaths, except from cancer (1.20). Diabetes: one extra egg per day goes with a 14% higher risk in three American cohorts, but not across 16 cohorts (1.07, not significant), nor in Europe, nor in Asia. TMAO: eating 2 or more egg yolks increases TMAO, a compound suspected of promoting heart disease (6 volunteers); but 4 eggs per day for 4 weeks did not increase it, unlike a choline supplement. Muscle: only two trials, one lasting 12 weeks on 30 young men and a single session on 10; none with resistance training in women.
Recommended dosage
Trials have tested 2 eggs per day, 6 to 12 eggs per week, and 3 whole eggs right after every training session.
How to take it
- For muscle: 3 whole eggs right after the session, in the only 12-week trial, conducted on trained young men.
- Whole or white: at equal protein, the whole egg stimulated muscle protein synthesis more than the white after exercise.
- To lose weight: two eggs at breakfast only helped with a hypocaloric diet; without a diet, they did not cause any weight loss.
- For cholesterol: 6 to 12 eggs per week changed neither LDL nor blood glucose in diabetic or at-risk individuals, on a diet following guidelines.
- Trial duration: from 5 weeks per diet to 12 months.
- What does not work: in 22 overweight seniors, a high-protein diet with 3 eggs per day improved neither muscle quality, cardiometabolic health, nor inflammation over 12 weeks; it only preserved lean mass.
- What does not work: at equal protein, an egg-based breakfast did not cause people to eat less at lunch compared to a cereal breakfast, in 30 dieting women.
Did you know?
In a crossover trial, 2 eggs per day in a low-saturated-fat diet lowered LDL compared to 1 egg per week in a high-saturated-fat diet: it was saturated fat, not egg cholesterol, that drove LDL.
What the studies say
This prospective study and updated meta-analysis suggest that higher dietary cholesterol and egg consumption is associated with an increased risk of all-cause and cardiovascular disease mortality. Daily consumption of an additional 50 g egg was associated with a significantly higher risk of cardiovascular disease, particularly in US and European cohorts. These findings support restricted dietary cholesterol consumption for improving long-term health and longevity.
Zhao B, Zhao B, Gan L, Graubard BI, Männistö S, Albanes D, Huang J. — Circulation (2022) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more