Eggs

Once the general public accepts that dietary cholesterol is not a concern for cardiovascular disease risk, foods that have been labeled as high-cholesterol sources, including eggs, may be appreciated for their various other dietary components. One of the nutrients in eggs that deserves further discussion is egg protein. Egg protein has been recognized to be highly digestible and an excellent source of essential amino acids, with the highest attainable protein digestibility-corrected amino acid score. Egg protein has been shown to decrease malnutrition in underdeveloped countries, possibly increase height in children, and protect against kwashiorkor. Egg protein has been demonstrated to be important to skeletal muscle health and protective against sarcopenia. Egg protein also can decrease appetite, resulting in a reduction in the caloric intake from the next meal and weight reduction. Other protective effects of egg protein addressed in this review include protection against infection as well as hypotensive and anti-cancer effects.

BackgroundWhether consumption of egg and cholesterol is detrimental to cardiovascular health and longevity is highly debated. Data from large-scale cohort studies are scarce. This study aimed to examine the associations of egg and cholesterol intakes with mortality from all causes, cardiovascular disease (CVD), and other causes in a US population.Methods and findingsOverall, 521,120 participants (aged 50-71 years, mean age = 62.2 years, 41.2% women, and 91.8% non-Hispanic white) were recruited from 6 states and 2 additional cities in the US between 1995 and 1996 and prospectively followed up until the end of 2011. Intakes of whole eggs, egg whites/substitutes, and cholesterol were assessed by a validated food frequency questionnaire. Cause-specific hazard models considering competing risks were used, with the lowest quintile of energy-adjusted intake (per 2,000 kcal per day) as the reference. There were 129,328 deaths including 38,747 deaths from CVD during a median follow-up of 16 years. Whole egg and cholesterol intakes were both positively associated with all-cause, CVD, and cancer mortality. In multivariable-adjusted models, the hazard ratios (95% confidence intervals) associated with each intake of an additional half of a whole egg per day were 1.07 (1.06-1.08) for all-cause mortality, 1.07 (1.06-1.09) for CVD mortality, and 1.07 (1.06-1.09) for cancer mortality. Each intake of an additional 300 mg of dietary cholesterol per day was associated with 19%, 16%, and 24% higher all-cause, CVD, and cancer mortality, respectively. Mediation models estimated that cholesterol intake contributed to 63.2% (95% CI 49.6%-75.0%), 62.3% (95% CI 39.5%-80.7%), and 49.6% (95% CI 31.9%-67.4%) of all-cause, CVD, and cancer mortality associated with whole egg consumption, respectively. Egg white/substitute consumers had lower all-cause mortality and mortality from stroke, cancer, respiratory disease, and Alzheimer disease compared with non-consumers. Hypothetically, replacing half a whole egg with equivalent amounts of egg whites/substitutes, poultry, fish, dairy products, or nuts/legumes was related to lower all-cause, CVD, cancer, and respiratory disease mortality. Study limitations include its observational nature, reliance on participant self-report, and residual confounding despite extensive adjustment for acknowledged dietary and lifestyle risk factors.ConclusionsIn this study, intakes of eggs and cholesterol were associated with higher all-cause, CVD, and cancer mortality. The increased mortality associated with egg consumption was largely influenced by cholesterol intake. Our findings suggest limiting cholesterol intake and replacing whole eggs with egg whites/substitutes or other alternative protein sources for facilitating cardiovascular health and long-term survival.Trial registrationClinicalTrials.gov NCT00340015.

Increased commercial demand for monoclonal antibodies (mAbs) has resulted in the urgent need to establish efficient production systems. We previously developed a transgenic chicken bioreactor system that effectively produced human cytokines in egg whites using genome-edited transgenic chickens. Here, we describe the application of this system to mAb production. The genes encoding the heavy and light chains of humanized anti-HER2 mAb, linked by a 2A peptide sequence, were integrated into the chicken ovalbumin gene locus using a CRISPR/Cas9 protocol. The knock-in hens produced a fully assembled humanized mAb in their eggs. The mAb expression level in the egg white was 1.4-1.9 mg/mL, as determined by ELISA. Furthermore, the antigen binding affinity of the anti-HER2 mAb obtained was estimated to be equal to that of the therapeutic anti-HER2 mAb (trastuzumab). In addition, antigen-specific binding by the egg white mAb was demonstrated by immunofluorescence against HER2-positive and -negative cells. These results indicate that the chicken bioreactor system can efficiently produce mAbs with antigen binding capacity and can serve as an alternative production system for commercial mAbs.

BackgroundA substantial knowledge gap remains regarding the relationship between modifiable dietary factors and Alzheimer's disease risk. Eggs are a source of key nutrients that support brain health.ObjectivesThe aim of this study was to investigate the association between egg consumption and the incidence of Alzheimer's disease.MethodsData were drawn from the Adventist Health Study-2, a large, prospective cohort of United States Seventh-day Adventists, linked with Medicare records to identify Alzheimer's disease diagnosis. Diet and lifestyle factors were assessed using a validated food frequency questionnaire. Egg consumption was categorized by frequency, ranging from never/rarely to ≥5 times per week. The analytic sample included 39,498 participants (mean follow-up: 15.3 y), among whom 2858 developed Alzheimer's disease. Multivariable-adjusted Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted cubic spline analysis was conducted using continuous egg intake (g/d).ResultsEgg consumption was inversely associated with Alzheimer's disease risk. Compared with never/rarely consuming eggs, HRs (95% CIs) after adjusting for demographic, lifestyle, food groups, and comorbidities were 0.83 (0.75, 0.92) for 1-3 times per month, 0.83 (0.74, 0.94) for once per week, 0.80 (0.71, 0.90) for 2-4 times per week, and 0.73 (0.60, 0.89) for ≥5 times per week. In the spline model, zero egg intake was curvilinearly associated with an adjusted HR of 1.22 (1.11, 1.34) compared with 10 g/d.ConclusionsIn this health-conscious population, moderate egg consumption was associated with a significantly lower risk of Alzheimer's disease. These findings suggest a potential neuroprotective benefit of nutrients found in eggs when consumed as part of a balanced diet.