EGGS AND CHOLESTEROL
by: Ashley Dudley, Tsz Wing Ho and Mjin Song
Outline








Misconceptions about eggs and cholesterol
Cholesterol – dietary vs blood
Cardiovascular disease
Diabetes
Metabolic Syndrome
Dietary Recommendations
Health Benefits
Weight loss
Common Misconceptions
People often believe that…
 Dietary cholesterol directly affect blood cholesterol
 Eggs contain high amounts of fat
 Contributes to atherosclerosis
 Greater risk of developing cardiovascular diseases
 Egg consumption should be limited or avoided
Cholesterol: dietary vs blood

Dietary cholesterol may not directly affect serum
cholesterol
1/3 population is hypersensitive
 Little effect on LDL:HDL ratio
 Maintains ratio – key marker of CHD risk


Different types of LDL


Larger, more buoyant particles less atherogenic
Many studies blamed cholesterol for adverse results,
but dietary cholesterol intake is often correlated with
saturated fat intake; high saturated fat intake is
associated with high blood cholesterol and CHD.
Cholesterol Studies

1913 study by Anitschkow and Chalatow showed that
feeding high amounts of cholesterol to rabbits induced
atherogenesis.

Rabbits are highly sensitive to cholesterol
Weaknesses of animal studies
 Blood cholesterol response to dietary cholesterol is highly
variable across and within species
 Most animal species have different lipoprotein profiles
compared to humans
 In nonhuman primates, only extremely high doeses of
dietary cholesterol induce hypercholesterolemia and
atherosclerosis (1250-5000 mg/2500kcal)
Cardiovascular Diseases


Lack of evidence supporting a link between egg
consumption and CHD morbidity and mortality.
Percentage of saturated and trans fat calories in
diet is positively correlated with CHD risk.
Cardiovascular Diseases
Fig 1. Relative risk of CHD incidence in
males (Health professionals Follow up
study) and females (Nurses Health
Study) versus weekly egg consumption
Fig 2. Relationship between CVD
mortality rates in men aged 35-74
among 24 countries and per capita egg
consumption
Diabetes

Individuals with diabetes face an increased risk of
CHD with egg consumption
 Most
studies that show a link to CHD are on diabetic
patients

Possible relationship of egg consumption and
increased risk of type 2 diabetes mellitus.
 Mechanisms
by which high egg and cholesterol
consumption influence glucose homeostasis and diabetes
risks are largely unknown.
Diabetic Studies
Lithuanian study shows that participants who consumed
>5 eggs/wk had a threefold increased risk of
developing type 2 diabetes than those who consumed
<1 egg/wk
 High egg consumption (>7 eggs/wk) before and during
pregnancy were associated with increased risk of
developing gestational type 2 diabetes mellitus.
Study weaknesses

Data was self reported through a questionnaire
 Did not ask whether participants consumed yolks or whites
only

Metabolic Syndrome
Metabolic syndrome – a group of risk factors that
occur together and increase risk of cardiovascular
diseases and diabetes


Risk factors: central obesity, high blood pressure, high blood
fasting glucose levels, elevated TAG and low HDL
Overweight men with MetS on carb restricted diet
added eggs to diet for 12 weeks
 Significant
increase in HDL, with no change in LDL
 100% of individuals in egg group were no longer
classified as having metabolic syndrome.
Metabolic Syndrome Studies
Changes in plasma HDL levels from baseline to 12 weeks in overweight
men who consume a CRD including 3 eggs/wk or an egg substitute.
Cholesterol Dietary Recommendations

AHA recommends no more than 300mg/d for general
population in effort to reduce plasma cholesterol levels and
CHD risk


Proposed in the 1970’s where there was no enough
substantial evidence to support this



No epidemiological studies support this
Extrapolated data derived from early animal studies
Other countries do not support an upper limit, due to lack of
evidence


Those with CHD are recommend no more than 200mg/d
Focus on limiting intakes of sugar, salt, saturated and trans fats
and maintaining a healthy weight
Should upper limit be removed?

A more reasonable goal of 500mg/d is proposed
Cholesterol Dietary Recommendations
Benefits of Eggs
Most nutrients in eggs are found in the yolk
 Complete sources of protein (all 9
essential amino acids)
 Major source of lutein and zeaxanthin

Study in the Journal of Nutrition found
that women eating 6 eggs/wk for 12
weeks had increased macular
pigmentation, which protects retina
Choline
 Iron
 Vitamin D
 B Vitamins (riboflavin, folate)
 Zinc
 Lecithin

Eggs
1.00 each
50.00 grams
77.50 calories
Nutrient
choline
Amount
DV
(%)
Nutrient
Density
World's
Healthiest
Foods Rating
112.65 mg
26.5
6.2
very good
0.08 g
25.0
5.8
very good
selenium
15.40 mcg
22.0
5.1
very good
iodine
27.00 mcg
18.0
4.2
very good
0.26 mg
15.3
3.6
very good
6.29 g
12.6
2.9
good
molybdenum
8.50 mcg
11.3
2.6
good
vitamin B12
0.55 mcg
9.2
2.1
good
phosphorus
86.00 mg
8.6
2.0
good
vitamin B5
0.70 mg
7.0
1.6
good
vitamin D
26.50 IU
6.6
1.5
good
tryptophan
vitamin B2
protein
Weight Loss

Average egg contains
 210
mg of cholesterol
 1.5 g saturated fat
 6 g protein
 70 calories

Eggs promote satiety, casing lower caloric intake
throughout the day
2

eggs for breakfast may aid in weight loss
Cheap and convenient
Weight Loss
In comparison to a bagel based
breakfast, an egg based
breakfast helped participants
lose weight.
After 8 weeks, the egg based
breakfast showed:




61% greater reduction in BMI
65% greater weight loss
34% greater reduction in waist
circumference
16% greater reduction in body fat
percentage
Conclusion






Most misconceptions regarding eggs aren’t true.
Dietary cholesterol does not directly affect blood
cholesterol levels.
Eggs do not increase the risk of CHD in the general
population.
Those with diabetes should be cautious of egg
consumption, though further research is needed.
Upper limit needs to be rethought.
Eggs are nutrient dense and offer many benefits.
Sources








Constance, C. " The good and the bad: what researchers have learned about dietary cholesterol, lipid management and
cardiovascular disease risk since the Harvard Egg Study." The International Journal of Clinical Practice 2009 Oct; (suppl.
163):9-14, 27-43. National Center for Biotechnology Information. 5 Oct. 2012
<http://www.ncbi.nlm.nih.gov/pubmed/19751444>
Fernandez, Maria L., and Mariana Calle. “Revisiting Dietary Cholesterol Recommendations: Does the Evidence Support a Limit
of 300 mg/d?.” Current Athersclerosis Reports 2010 Nov; 12(6):377-83. National Center for Biotechnology Information. 5
Oct. 2012 <http://www.ncbi.nlm.nih.gov/pubmed/20683785>
Spence, J D., David JA Jenkins, and Jean Davignon. “Dietary cholesterol and egg yolks: Not for patients at risk of vascular
disease.” The Canadian Journal of Cardiology 2010 Nov; 26(9):e336-9. National Center for Biotechnology Information. 5
Oct. 2012 <http://www.ncbi.nlm.nih.gov/pubmed/21076725>
Radzeviciene, Lina and Rytas Ostrauskas. “Egg consumption and the risk of type 2 diabetes mellitus: a case-control study.”
Public Health Nutrition 2012 Aug;15(8):1437-41. National Center for Biotechnology Information. 5 Oct. 2012
<http://www.ncbi.nlm.nih.gov/pubmed/22390963>
Qiu, Chunfang, et al. “Risk of Gestational Diabetes Mellitus in Relation to Maternal Egg and Cholesterol Intake.” American
Journal of Epidemiology 2011 Mar 15;173(6):649-58. National Center for Biotechnology Information. 5 Oct. 2012
<http://www.ncbi.nlm.nih.gov/pubmed/21324948>
Fernandez, Maria L. “Rethinking Dietary Cholesterol.” Current Opinion in Clinical Nutrition and Metabolic Care 2012
Mar;15(2):117-21. National Center for Biotechnology Information. 5 Oct. 2012 <
http://www.ncbi.nlm.nih.gov/pubmed/22037012>
Mutungi, Gisella, et al. “Dietary Cholesterol from Eggs Increases Plasma HDL Cholesterol in Overweigh Men Consuming a
Carbohydrate-Restricted Diet.” The Journal of Nutrition February 2008 vol. 138 no. 2 272-276 University of California
Berkeley Bioscience and Natural Resources Library, Berkeley, CA. 5 Oct. 2012
<http://jn.nutrition.org/content/138/2/272.abstract>
Bowden, Jonny. The 150 Healthiest Foods on Earth. Beverly, MA: Fair Winds Press, 2007.
Sources

http://www.weightlossresources.co.uk/weight_loss/weight_loss_tips/eat_eggs.htm

http://www.ncbi.nlm.nih.gov/pubmed/18679412