OK, are eggs good or bad?

I am posting an interview on the benefits of eating eggs daily. Eggs yolks have lots of lutein and zeaxanthine, both of which are highly and preferentially concentrated in the macula of the eye. They are both yellow compounds which have the ability to attenuate UV light. That’s a good thing. They are also anti-oxidants as well. We know that normal maculae have high amounts of each of these compounds. We also know that macular degeneration maculae have almost none. Thus it seems that having lots of these two compounds is a good thing.
Many people have been advised by their physician not to eat eggs, thinking that dietary cholesterol intake will make worse an elevated blood cholesterol.
Dietary intake of egg yolks does not effect blood cholesterol. It would take 30 to 45 eggs daily to equal the amount of cholesterol that is circulating in your blood at any one time. The vast majority of blood cholesterol comes from the liver. It is liver manufacture of cholesterol that is targeted by Statin drugs. The following interview will help support the argument that eating eggs is good for us.

Jim McNabb, MD

Macular Pigment, Cholesterol Lowering and Egg Yolk Consumption
Rohini Vishwanathan, Ph.D. (candidate)
Biomedical Engineering and Biotechnology Program
Department of Clinical Laboratory and Nutritional Sciences
Center for Health and Disease Research
University of Massachusetts Lowell
3 Solomont Way, Suite 4
Lowell, MA 01854-5125
978-934-4506 / 978-934-2034 (FAX)
v_rohini@hotmail.com / nicolosi.robert@yahoo.com

“Consumption Of 2 And 4 Egg Yolks/d For 5 Wk Increases Macular Pigment Concentrations In Older Adults With Low Macular Pigment Taking Cholesterol-Lowering Statins,”
Am J Clin Nutr, 2009; 90(5): 1272-9. 47554 (12/2009)

Kirk Hamilton: Can you please share with us your educational background and current position?
Rohini Vishwanathan: I am presently pursuing my Ph.D. in Biomedical Engineering and Biotechnology at University of Massachusetts, Lowell with a research concentration in nutritional biochemistry under the
guidance of Dr. Robert Nicolosi and Dr. Thomas Wilson. I expect to graduate by May 2010. I received a bachelor’s degree in microbiology – biochemistry in 2000 and a master’s degree in biochemistry in 2002 from Mumbai University, India. I received a doctoral fellowship in nutrition from the American Egg Board – Egg Nutrition Center in 2008.
KH: What got you interested in studying the role of egg yolks and macular pigment optical density (MPOD)? Exactly what is MPOD?
RV: My research interest is to study nutritional interventions that could be used in the prevention and/or treatment of diseases such as age-related macular degeneration and cardiovascular disease. During my first year in the Ph.D. program I worked with Elizabeth Goodrow-Kotyla, clinical nutrition coordinator at University of Massachusetts Lowell, on a study that showed consumption of one egg per day significantly increased serum lutein and zeaxanthin in an older adult population not consuming a statin. Also, in a collaborative study with Wenzel et al., University of New Hampshire, Durham, we reported 6 eggs per week for 12 weeks effectively
increased MPOD in women aged 24-59 years. Egg yolks are a highly bioavailable source of lutein and zeaxanthin. The 2 and 4 egg yolks a day study aimed to decipher the ideal dosage of eggs that could raise MPOD without adversely affecting serum total and LDL cholesterol. The study was designed by Drs. Robert Nicolosi and Thomas Wilson.
Macular pigment optical density or MPOD is a number ranging from 0 to 1.0 that corresponds to the density of a pigment in the macula lutea region of the retina. The pigment is primarily composed of nutrients lutein and zeaxanthin that can only be obtained from diet, and meso-zeaxanthin, formed by isomerization of lutein in the macula.
KH: What is the biochemistry of macular degeneration or the macula that might be improved with supplementation of the components of egg yolk?
RV: As stated in the previous response, lutein and zeaxanthin consumed in the diet exclusively accumulate in the macula, a region in the posterior pole of the retina to form a yellowish colored macular pigment. The macular pigment layer, having an absorption maximum of 460 nm, filters blue radiation of light and protects the underlying retinal cells, which are responsible for vision, from oxidative damage. Low macular pigment density is one of the pre-disposing risk factors for dry age-related macular degeneration (AMD). Thus, consuming egg yolks, a highly bioavailable source of lutein and zeaxanthin, could improve macular pigment density and protect against AMD.
KH: Where did you come up with 2-4 egg yolks per day? Were they from free range, antibiotic and hormone free chickens, or were these factory farm produced eggs?
RV: As stated earlier our previous study showed consumption of one egg per day significantly increased serum lutein and zeaxanthin in an older adult population not consuming a statin. Also in a collaborative study with University of New Hampshire, Durham, we reported 6 eggs per week for 12 weeks effectively increased MPOD in women aged 24-59 years of age. Egg yolks are a highly bioavailable source of lutein and zeaxanthin, the 2 and 4 egg yolks/d study aimed to decipher the ideal dosage of eggs that could raise MPOD without adversely affecting serum total and LDL cholesterol. The egg yolks used for the study were from large, nonenriched eggs, which were obtained from Aramark Corporation, the food service supplier for the university, who prepared the food items. I am not sure if they were antibiotic and hormone free or free range.
KH: Were the yolks given with meals or away from meals? In a single dose or divided dose?
RV: Food items were prepared that either contained two egg yolks or four egg yolks depending on the study phase. Foods were delivered to the subjects two times in a week during the egg yolk phases. Some of the foods choices were baked custard, egg salads, waffles, pancakes, smoothies, breakfast wraps, deviled eggs and quiche. Subjects consumed one food item per day either as a single dose or divided dose as per their preference.
KH: Were the active components of egg yolks measured before, during or after the intervention (i.e. lutein, zeaxanthin)? Did they correlate with the intervention and the effect on the MPOD?
RV: Lutein and zeaxanthin were measured in a random cohort of egg yolks that were used to prepare the food items during the study period. A greater response was observed in serum zeaxanthin concentrations which may have been due to the high amounts of zeaxanthin (mean: 230 μg/yolk) in the egg yolks than previously reported. The significant MPOD increases observed in the central retinal eccentricities (0.25º and 0.5º) may have been an effect of the greater serum zeaxanthin response compared with lutein.
KH: Can you tell us about your study and the basic results?
RV: The study showed consumption of 2 egg yolks/d for 5 weeks increased serum lutein and zeaxanthin significantly by 16% and 36% respectively. Consumption of 4 egg yolks/d for 5 weeks also increased serum lutein and zeaxanthin concentrations significantly by 24% and 82% respectively. MPOD response was observed only in subjects who entered the study with a low MPOD. Two egg yolks/d for 5 weeks caused 31% increase in MPOD at the 0.5º retinal eccentricity, although this increase was not statistically significant (P = 0.059) it was
clinically relevant as MPOD increased by 0.08 units in 5 weeks. Four egg yolks/d for 5 weeks significantly increased MPOD by 48% at 0.25º, 54% at 0.5º and 50% at 1º retinal eccentricities. Serum total cholesterol did not change significantly after both 2 and 4 egg yolk phases. Serum HDL cholesterol increased significantly by 5% after both 2 and 4 egg yolk phases. Serum LDL cholesterol changes were not statistically significant, but tended to decrease (- 4%) after the 2 egg yolk phase and tended to increase (4%) after the 4 egg yolk phase.
KH: Were there any side effects with this egg yolk intervention? How was the patient compliance?
RV: There were no side effects observed during the study and all 52 subjects complied with the study protocol. Compliance was monitored through several means. Empty food containers were returned and weekly phone calls were made to the subjects. Also, 7 day diet records completed once during each phase was used to monitor egg yolk consumption.
KH: Were you surprised to see a beneficial effect on serum HDL with the egg yolk consumption?
RV: Yes. The hypothesis was that cholesterol lowering medications or statins (94% of subjects were taking statins) would prevent significant increases in serum total cholesterol and LDL cholesterol during egg yolk phases.
KH: Who is a candidate for egg yolk therapy? All aging individuals or only those with maculopathies?
RV: Egg yolks or eggs in general are a nutrient rich food as they contain lutein and zeaxanthin in a highly bioavailable matrix, and also high quality protein, choline and other vitamins. The results of the present study showed egg yolks increased serum lutein, zeaxanthin (which are also potent antioxidants) and MPOD thus providing beneficial effects to a population at a risk of dry AMD. AMD is the leading cause of vision loss in the elderly population. We are presently studying the effect of consuming 12 eggs per week for one year in a population diagnosed with early to mid-stage dry AMD. The subjects are advised to limit intake of saturated fat in their diet. The hypothesis is consumption of 12 eggs per week for one year would increase MPOD and also
prevent progression of dry AMD. Eggs could thus be both a beneficial and affordable nutrient rich food for the aging population, specifically for a population affected with AMD when consumed as part of a healthy diet.