Internally Made shade
Lutein gives skin and eyes a potent defense against sun damage.
When you think of all the positive connotations associated with the word “sunshine”—love, uplift, happiness—it seems a shame that the sun is now mostly known for its role in promoting skin and eye damage. But it’s true; solar ultraviolet (UV) rays can cause skin to look old and wrinkled while also leading to dimmed eyesight. UV has been implicated in skin cancer as well. While the vast majority of cases are relatively benign basal and squamous tumors, more than 62,000 people develop melanoma each year—and more than 11,000 die of it.
The standard advice for ducking UV’s long reach—using sunblock, wearing a floppy hat and eye protection, staying inside at midday—still stands. But there are nutrients that can provide “internal sunglasses,” the most notable of which is lutein.
UV and You
UV rays come in two basic types, A and B (a third kind, UVC, usually doesn’t reach the earth’s surface). Sunblocks generally only screen out UVB, which reaches peak strength in the summer and is responsible for both suntans and sunburns. UVB isn’t all bad; in controlled doses it spurs the skin to produce vitamin D. Too much UVB exposure, though, can degrade collagen, the main protein found in skin, and harm cellular DNA.
Scientists once thought that UVA, which maintains a constant intensity year-round, was fairly harmless. However, recent research has shown that this UV wavelength also degrades collagen. In addition, it produces cell-damaging free radicals.
Structures in the eye are subject to injury inflicted by both UVA and UVB. The eye can also suffer damage caused by blue light, which is part of the visible spectrum.
Neutralizing the Rays
One way to extend your UV defenses is to use what’s called a “broad spectrum” sunblock that impedes both UVA and UVB. But no sunblock—or sunglasses, for that matter—can supply total protection.
That’s where lutein comes in. This carotenoid (and its ever-present partner, zeaxanthin) is found in the skin and is particularly concentrated in the macula, the part of the retina responsible for clear central vision. Lutein helps quench free radicals and tame chronic inflammation; in the eye it also absorbs blue light.
Supplemental lutein/zeaxanthin increases macular density, which is why it has shown such promise in retarding age-related macular degeneration (ARMD), a disorder that can obliterate central vision. Increased lutein intake may slow down cataract development and progression (Graefe's Archive for Clinical and Experimental Ophthalmology 1/09). Conversely, low lutein levels have been associated with an increased risk of diabetic retinopathy, another form of macular disease (British Journal of Nutrition 1/09).
Lutein’s benefits go well beyond UV protection. It may interfere with atherosclerosis, the deposition of arterial plaque; low lutein levels have been found in people with coronary artery disease. Higher lutein intakes have even been associated with reduced risk for several types of cancer.
Dietary sources of lutein and zeaxanthin include broccoli, cabbage, corn, egg yolk, kiwifruit and lettuce. Lutein and zeaxanthin are also available in supplement form, often in sun protection formulations with other nutrients such as astaxanthin, superoxide dismutase/gliadin complex and vitamins A, C and E.
Don’t worry about going out to play in the sun. Just take all the sensible precautions—including adding lutein/zeaxathin to your diet.