Professor concludes that egg consumption is an effective method to increase macular pigment

This study was published in the Journal of Nutrition 2006 Oct;136(10):2568-73

Study title and authors:
A 12-wk egg intervention increases serum zeaxanthin and macular pigment optical density in women.

Wenzel AJ, Gerweck C, Barbato D, Nicolosi RJ, Handelman GJ, Curran-Celentano J.
Psychology Department, University of New Hampshire, Durham, NH 03824, USA. awenzel@unnh.edu

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/16988128

This study was cancucted by professor Adam Wensel from the University of New Hampshire. Wenzel states eggs are one of the most nutrient-dense foods regularly consumed in the human diet. In addition to several essential vitamins and minerals, eggs contain the carotenoids lutein and zeaxanthin. Lutein and zeaxanthin are collectively called macular pigment and higher levels are associated with improved eye health.

The objective of the study was to determine whether increased consumption of eggs would increase levels of lutein, zeaxanthin and macular pigment. The study lasted for 12 weeks and included 24 women, aged between 24 and 59, who were told to continue with their normal diet and additionally were also assigned into groups to consume the following:
(i) A sugar filled pill per day (pill group).
(ii) Six supermarket eggs per week (supermarket egg group).
(iii) Six organic eggs per week (organic egg group).

The study found:
(a) Levels of lutein decreased by 9.5% in the pill group.
(b) Levels of zeaxanthin decreased by ~17% in the pill group.
(c) Levels of macular pigment remained about the same in the pill group.
(d) Levels of lutein increased by 22.6% in the supermarket egg group.
(e) Levels of zeaxanthin increased by ~47% in the supermarket egg group.
(f) Levels of macular pigment increased by ~50% in the supermarket egg group.
(g) Levels of lutein increased by 26.1% in the organic egg group.
(h) Levels of zeaxanthin increased by ~79% in the organic egg group.
(i) Levels of macular pigment increased by ~14% in the organic egg group.

Professor Wenzel concludes that the bioavailability of the carotenoids; lutein and zeaxanthin is high in egg yolks, and that egg consumption is an effective method to increase macular pigment. 

Egg yolk is a highly bioavailable source of lutein and zeaxanthin

This study was published in the American Journal of Clinical Nutrition 1999 Aug;70(2):247-51

 

Study title and authors:

Lutein and zeaxanthin concentrations in plasma after dietary supplementation with egg yolk.

Handelman GJ, Nightingale ZD, Lichtenstein AH, Schaefer EJ, Blumberg JB.

Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA, USA. Handelman_lp@hnrc.tufts.edu

 

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/10426702

The lead researcher of the study, Dr Garry Handelman from Tufts University Boston, notes that lutein and zeaxanthin have been identified as carotenoids that accumulate in the macular region of the human retina that may play a role in the prevention of age-related macular degeneration and some forms of cancer.

The study sought to determine whether levels of lutein and zeaxanthin are elevated after consumption of egg yolks. The study included 11 men and women who firstly consumed diets without any egg yolks for 4.5 weeks, and secondly consumed similar diets with the addition of 1.3 egg yolks per day for another 4.5 weeks.

The study found:
(i) The diets containing egg yolks raised levels of lutein by 39% compared to the diets containing no egg yolks.
(ii) The diets containing egg yolks raised levels of zeaxanthin by 128% compared to the diets containing no egg yolks.

Dr Handelman concluded: "Egg yolk is a highly bioavailable source of lutein and zeaxanthin".

Lutein bioavailability from eggs are higher than that from other sources such as supplements and spinach

This study was published in the Journal of Nutrition 2004 Aug;134(8):1887-93

 

Study title and authors:

Lutein bioavailability is higher from lutein-enriched eggs than from supplements and spinach in men.

Chung HY, Rasmussen HM, Johnson EJ.

Jean Mayer U.S. Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.

 

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/15284371

Chung notes that lutein may be protective against diseases such as age-related macular degeneration.

This study investigated the bioavailability from four sources; (i) lutein supplement, (ii) lutein ester supplement, (iii) spinach, (iv) eggs. The study included ten men who were administered one of the four lutein doses for nine days.

The study found:
(a) Lutein levels rose by 323.4% in the egg consumers.
(b) Lutein levels rose by 140.1% in the spinach consumers.
(c) Lutein levels rose by 82.1% in the lutein supplement consumers.
(d) Lutein levels rose by 81.9% in the lutein ester supplement consumers.

The researchers concluded that lutein bioavailability from eggs are significantly higher than that from other sources such as lutein, lutein ester supplements, and spinach: And that eggs may decrease the risk of certain diseases such as age-related macular degeneration.

Consuming eggs significantly increases levels of lutein and zeaxanthin

This study was published in the Journal of Nutrition 2006 Oct;136(10):2519-24

 

Study title and authors:

Consumption of one egg per day increases serum lutein and zeaxanthin concentrations in older adults without altering serum lipid and lipoprotein cholesterol concentrations.

Goodrow EF, Wilson TA, Houde SC, Vishwanathan R, Scollin PA, Handelman G, Nicolosi RJ.

Center for Health and Disease Research, Department of Clinical Laboratory and Nutritional Sciences, University of Massachusetts Lowell, MA 01854, USA.

 

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/16988120

The lead author of the study, Elizabeth Goodrow, notes that lutein and zeaxanthin accumulate in the macular pigment of the retina, and are reported to be associated with a reduced incidence of age-related macular degeneration. A rich source of lutein and zeaxanthin in the American diet is the yolk of chicken eggs.

The objective of the study was to investigate the effect of egg consumption on the levels of lutein, zeaxanthin and cholesterol in individuals over 60 years of age. The study included 33 men and women who consumed one egg per day for five weeks.

The study found:
(a) Levels of lutein increased by 26% after five weeks of consuming one egg per day.
(b) Levels of zeaxanthin increased by 38% after five weeks of consuming one egg per day.
(c) Cholesterol levels were not affected throughout the study.

The findings of the study show that consuming one egg per day significantly increases levels of the carotenoids lutein and zeaxanthin.

Egg yolk consumption is associated with a decreased risk of age-related macular degeneration

This study was published in the American Journal of Clinical Nutrition 2009 Nov;90(5):1272-9

Study title and authors:
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.

Vishwanathan R, Goodrow-Kotyla EF, Wooten BR, Wilson TA, Nicolosi RJ.
Department of Clinical Laboratory and Nutritional Sciences, Center for Health and Disease Research, University of Massachusetts Lowell, Lowell, MA 01854-5125, USA.

This study can be accessed at: http://www.ncbi.nlm.nih.gov/pubmed/19759170

The carotenoids of the macular pigment, lutein and zeaxanthin, may reduce the risk of dry, age-related macular degeneration, see here, and light induced retinal damage.

Macular pigment optical density is the thickness or density of the macular pigment. Research has shown that a low macular pigment optical density is a key risk factor for age-related macular degeneration, see here, while a high macular pigment optical density not only reduces one’s risk for but also helps to improve visual performance.

Low levels of high density lipoprotein (HDL) cholesterol are associated with an increased risk of age-related macular degeneration see here.

The study evaluated the levels of lutein, zeaxanthin, macular pigment optical density and HDL cholesterol in 52 adults, aged 60 and over, after the consumption for five weeks of either (i) two egg yolks per day (ii) four egg yolks per day. 

The study found:
(a) Lutein levels increased by 15.4% after consumption of two egg yolks per day, and increased by 28.4% after consumption of four egg yolks per day.
(b) Zeaxanthin levels increased by 36.3% after consumption of two egg yolks per day, and increased by 81.8% after consumption of four egg yolks per day.
(c) Macular pigment optical density levels increased by 3.9% after consumption of two egg yolks per day, and increased by 24.4% after consumption of four egg yolks per day.
(d) High density lipoprotein (HDL) cholesterol levels increased by 5.4% after consumption of both two and four egg yolks per day.

The results from the study suggest that egg yolk consumption is associated with a decreased risk of age-related macular degeneration.