Zeaxanthin is one of the two pigments found in the back of the eye.
The back of the eye is something like a movie screen.
Images are projected on to it as light passes through the eye's lenses.
This image is transmitted to the brain and that's how you see what is in front of you.
This film screen in the back of the eye is called the retina.
There is a small highly sensitive area within the retina that is called the macula.
A disease called "age-related macular degeneration" or AMD is the most common cause of blindness among the elderly.
Within the central macula, zeaxanthin is the predominate pigment.
The pigment in the surrounding retina is primarily lutein.
Zeaxanthin and lutein are in the carotenoid family, which also includes beta-carotene.
Beta-carotene is converted within the body to vitamin A.
Vitamin A is an essential nutrient.
Insufficient intake causes a variety of diseases, starting with dry flaky skin and sometimes ending in blindness or death.
The other carotenoids are not (yet) considered essential, since there is no specific acute disease that is caused by their absence in the diet.
However, there is growing evidence that many chronic, life-threatening and age-related diseases are caused by low intake of various carotenoids and other "micronutrients".
Micronutrients are those that are present in many different foods, but only in small amounts.
The roles that they play in the human body are not yet fully understood.
Many health experts believe that these micronutrients are lacking in most people's diets, particularly the typical American diet.
Approximately 1.
2 million Americans are affected by AMD.
In a six year study, the National Eye Institute in Maryland found that lutein and zeaxanthin protect against blindness in those people that have AMD.
Several studies indicate that the micronutrients reduce the risk of AMD, altogether.
There are several other risk factors, including family history.
The lifetime risk of developing AMD is 50% among people who have or had a relative with the condition, versus 12% of people with no family history of the disease.
Yet, even the family prevalence may be related to the body's ability to create specific nutrients.
For example, ATP is a nutrient that is not considered essential because, it is created within the cells of the human body.
But, in people with a family history of AMD, there is often a mutated gene that interferes with the body's ability to synthesize or make ATP.
ATP is the cell's energy.
When ATP production is inadequate, cellular function is negatively affected.
High blood pressure, high cholesterol, obesity, high intake of dietary fat and oxidative stress all contribute to age-related macular degeneration.
In the typical American diet 42% of the caloric intake is from fat.
30% should be the max and 20-25% is probably healthier.
But, regardless of how healthy your diet is, it is a relative impossibility to get all of the important micronutrients in quantities sufficient to protect your long-term health, without supplementation.
Most experts recommend 50mg of lutein and 10 of zeaxanthin for daily supplementation.