By Chloe Bennett, B.Sc.

There have been countless debates regarding the health impact of
regular egg consumption. While research has shown that consumption of
the food product for breakfast can lead to increased weight loss,
recent evidence shows that eating three eggs per week can increase the
risk of early mortality.

Image Credit: LightField Studios/Shutterstock.com

Are Eggs Good for Heart Health?

There has been on-going debate regarding the impact of the regular
consumption of eggs on the cardiovascular system. Currently, there is
conflicting literature relating to the relationship between egg
consumption, cholesterol, and the prevalence of coronary heart disease
(CHD).

Based on a 2017 study, there was a consensus that eggs were safe for
the heart. This aligned with guidance from the Dietary Guidelines for
America, who noted that the link between cardiovascular disease and
dietary cholesterol was minimal.

The guidelines were based on the fact that the association between
egg-derived cholesterol and other food products containing “bad”
cholesterol and CHD was considered less significant compared to the
well-supported impact of saturated fat on low-density lipoprotein
cholesterol – a key risk factor for atherosclerosis.

However, more recent research has found that eating a minimum of three
eggs per week can increase the likelihood of early death.

A team of researchers from the Department of Preventive Medicine at
Northwestern University presented evidence that eating three eggs per
week or 300 milligrams or more of cholesterol per day can increase the
risk of death.

A single large egg contains approximately 186 milligrams of
cholesterol. Meaning those who eat on average three large eggs within
a meal would be consuming approximately 558 milligrams of cholesterol.

The study followed over 29,000 participants for 17 years. During the
research, 5400 cardiovascular events were recorded, comprised of 113
fatalities caused by heart disease, 1897 cases of heart disease, and
1302 cases of stroke. Six thousand one hundred thirty-two of the
participants died from other non-cardiovascular-related causes.

Data analysis revealed that consuming an extra 300 milligrams of
cholesterol per day was linked to a 3.2% increased risk of developing
heart disease in addition to a 4.4% increased risk of dying early due
to any cause.

Image Credit: Naeblys/Shutterstock.com

The authors noted that the results serve as a reminder that eggs,
especially the yolk, contain cholesterol which can cause adverse
health consequences.

Therefore, to reduce the risk of CHD, less cholesterol should be
consumed. However, as a purely observational study, other factors
could have influenced the data.

The data also contrasts against literature outlining the benefits of
egg consumption on several health parameters, including weight
management and eye health.

Eggs and Weight Loss

Eggs are considered to provide an essential source of protein for
humans. They compare favorably to other protein sources, being only
inferior to breast milk. The yolk protein, in particular, has been
reported to have larger satiety effects compared to other isocaloric
foods with lower levels of satiety.

Research examining the impact of low satiety and high satiety meals of
the same caloric content on weight loss found participants consumed
fewer calories after eating a breakfast containing eggs.

Those consuming the egg and bagel breakfast lost more weight after
eight weeks. Similar research has found that those consuming the same
breakfast without the egg component were less satiated, hungrier, and
had higher insulin levels three hours after eating.

Based on this evidence, consuming eggs as part of breakfast may have
positive effects on those wishing to lose weight through the reduction
of calorie intake.

Nutritional Components

Eggs are relatively cheap, yet highly nutritious food products that
boast a plethora of nutrients essential for human health. One egg
contains plenty of vitamins, minerals, fats, essential proteins, and
bioactive compounds and hosts favorable nutrient to energy density
ratios.

Macronutrient-wise, eggs contain many essential vitamins, including
vitamin A, vitamin B12, vitamin, D, riboflavin, and folate, alongside
a range of minerals such as sodium, iron, calcium, and potassium.

Eye Health

The pigments responsible for giving egg yolks their yellow/orange
color have received interest due to their role in eye health.

Carotenoids – the pigment responsible – is comprised of lutein and
zeaxanthin which are unable to be synthesized by the human body and
require dietary intake.

The pigments are also found in the yellow spot of the retina, which
improves the clarity of vision, protects the macula from blue light
damage, and removes reactive oxygen species.

Eating foods containing carotenoids has been associated with the
reduced likelihood of developing several ocular conditions, including
cataracts and age-related macular degeneration.

References and Further Reading

Eckel, R.H., (2019). Reconsidering the importance of the association
of egg consumption and dietary cholesterol with cardiovascular disease
risk. Jama, 321(11), pp.1055-1056. Doi: 10.1001/jama.2019.1850
Dietary Guidelines Advisory Committee. (2015). Scientific Report of
the 2015 Dietary Guidelines Advisory Committee: Advisory Report to the
Secretary of Health and Human Service and the Secretary of
Agriculture. Washington, DC: US Dept of Agriculture, Agricultural
Research Service.
Zhong, V.W., Van Horn, L., Cornelis, M.C., Wilkins, J.T., Ning, H.,
Carnethon, M.R., Greenland, P., Mentz, R.J., Tucker, K.L., Zhao, L.
and Norwood, A.F. (2019). Associations of dietary cholesterol or egg
consumption with incident cardiovascular disease and mortality. Jama,
321(11), pp.1081-1095. Doi: 10.1001/jama.2019.1572
Kuang, H., Yang, F., Zhang, Y., Wang, T. and Chen, G. (2018). The
impact of egg nutrient composition and its consumption on cholesterol
homeostasis. Cholesterol, 2018. Doi: 10.1155/2018/6303810
Vander Wal, J.S., Marth, J.M., Khosla, P., Jen, K.C. and Dhurandhar,
N.V. (2005). Short-term effect of eggs on satiety in overweight and
obese subjects. Journal of the American College of Nutrition, 24(6),
pp.510-515. https://doi.org/10.1080/07315724.2005.10719497
Ratliff, J. and Leite, J.O., 2010. de Ogburn R, Puglisi MJ, VanHeest
J, Fernandez ML. (2010). Consuming eggs for breakfast influences
plasma glucose and ghrelin, while reducing energy intake during the
next 24 h in adult men. Nutr Res, 30, pp.96-103. Doi:
10.1016/j.nutres.2010.01.002
Vander Wal, J. S., Gupta, A., Khosla, P., & Dhurandhar, N. V. (2008).
Egg breakfast enhances weight loss. International Journal of obesity,
32(10), 1545-1551. https://doi.org/10.1038/ijo.2008.130.
Seddon, J. M., Ajani, U. A., Sperduto, R. D., Hiller, R., Blair, N.,
Burton, T. C., … & Yannuzzi, L. A. (1994). Dietary carotenoids,
vitamins A, C, and E, and advanced age-related macular degeneration.
Jama, 272(18), 1413-1420. 10.1001/jama.1994.03520180037032