Scientists Eye Benefits of Spinach
A scene as it might be viewed by a person with age-related macular degeneration.
Credit: National Eye Institute, National Institutes of Health

In the wake of the E. coli outbreak in which dozens of Americans were poisoned by tainted spinach, consumers might be weighing the vegetable's benefits against the risks of contamination.

Spinach is known for its high fiber content and its abundance of antioxidants and vitamins that studies have shown might decrease the risk of stroke and developing cataracts. The leafy green that gave Popeye his fictional super-strength might also promote super-sharp eyesight in the real world.

Green vegetables like spinach, kale and broccoli are particularly rich in two antioxidants called lutein and zeaxanthin that produce a substance which scientists think helps protect the eyes against age-related macular degeneration (AMD), the leading cause of irreversible blindness in Western societies. Researchers at the University of Manchester announced today that they are now using a new device to investigate whether the substance can help people who already suffer from the disease.

AMD primarily affects elderly people, and sufferers slowly lose their central vision, which makes day-to-day activities difficult. [Example: Good vision / AMD-impaired]

When lutein and zeaxanthin (found in high concentrations in spinach) combine, they form a yellow oil, called a macular pigment. The pigment coats the macula, a small area of the retina that is responsible for distinguishing details and colors in central vision, and is thought to prevent the destruction of retinal cells by excess light and oxidation.

"Our work has already found strong evidence to suggest that macular pigment provides some protection against AMD, but we want to discover whether eating vegetables rich in these chemicals will have a direct impact on the disease," said Ian Murray, the lead researcher of the new study.

The researchers have built a device to measure the levels of macular pigment in people with early stages of the disease. If they are found to have low levels, they can then be advised to eat more spinach and other vegetables rich in the antioxidants.

"Having their macular pigment measured and learning about the health of their eyes might be the first step to a change in lifestyle for many people," Murray said.