Dietary Carotenoids Confirmed To Benefit
Eye Health According
To a New Study
Phytochemical - plant extracts... carotenoids: lutein
and zeaxanthin benefit eye health, according to a new
study published in the Journal of Food Science.

Carotenoids, a group of pigments found mainly in green
leafy vegetables and colored fruits, are deposited selectively
in different tissues. Lutein and Zeaxanthin, found in kale and
spinach, are deposited in the retina while Lycopene, for
example, found richly in tomatoes, is concentrated in
the prostate.

Scientists have long suspected a link between Lutein and
Zeaxanthin and improved eye function. IAs far back as 1866,
Schulze suggested that the yellow pigments of the macula led
to improvements in human vision. These pigments were later
found to be derived from dietary Lutein and Zeaxanthin.

In 1933, the scientists Walls and Judd suggested that these
yellow intraocular pigments could improve visual performance
by absorbing light scattered both within, by minimizing glare,
and outside of the eye. This resulted, they suggested, from
increasing visual range by absorbing blue light scattered in
the atmosphere and by improving spatial vision through
enhancing contrast and reducing chromatic blur.

The latest study concluded that: "It seems clear that MP
(macular pigment) does influence visual performance through,
at least, a few optical mechanisms. The most robust effects
appear to be related to its actions as an optical filter."

Macular pigment is thought to improve glare performance
through absorption of forward scattered short-wave (blue) light.
And there's preliminary data to suggest that it increases visual
range by absorbing short-wave scattered light in the atmosphere, according to the researchers.

The pigment also appears to enhance contrast by improving
the visibility of colored edges through differential absorption
across a color border

Lutein and Zeaxanthin could also improve vision through
biological means. There's much evidence to suggest that the pigments protect the retina and lens and prevent age-related
eye diseases such as macular degeneration and cataracts.

But the ability of Lutein and Zeaxanthin to filter light depends
on individual differences in the dietary intake of these
carotenoids, said the researchers. One study specifically linked
low average levels of macular protein with low average intakes
of Lutein and Zeaxanthin, the equivalent of several tablespoons
of spinach.

According to the researchers, if amounts of macular pigment in
the eye vary so significantly, any function these pigments might
serve would vary equally significantly. And it is likely that a
healthier retina and lens, particularly in the elderly, is related
to improved visual performance.

Source: Journal of Food Science
"The Influence of Dietary Lutein and Zeaxanthin on Visual Performance "