NEW YORK - People who eat plenty of salads, or raw vegetables in general, typically have higher blood levels of several important nutrients, according to a large study of U.S. adults.

Researchers found that even one serving of raw vegetables a day moved people closer to getting the recommended amounts of vitamins A, E, B6 and folic acid. And as salad and raw vegetable intake increased, so did blood levels of vitamins C and E, folic acid and several carotenoids -- antioxidants that give yellow, orange and red hues to many vegetables and fruits.

Unfortunately, few Americans regularly eat raw vegetables, according to the researchers, led by Dr. L. Joseph Su of the Louisiana State University Health Sciences Center in New Orleans.

Of the nearly 18,000 U.S. adults surveyed, only 18 percent to 38 percent said they ate salads. White women younger than 45 had the highest rate; older African Americans had the lowest.

In general, black adults of all ages were less likely to eat salads and other raw vegetables than their white counterparts, Su and colleague Dr. Lenore Arab report in the Journal of the American Dietetic Association.

The particularly low vegetable intake among African Americans is "alarming," the researchers write.

They based their findings on data from a federal health and nutrition survey of 17,688 U.S. adults. Participants reported on their diets over the last 24 hours and had medical exams that included measuring nutrient levels in the blood.

Overall, salad and veggie consumers had higher blood levels of a range of nutrients -- 15 percent higher, on average, than people who reported a menu free of raw vegetables. They were also two to three times more likely to meet the recommended daily intake for vitamin C.

What's more, the "dose" of salad didn't have to be large to help people meet their daily requirements for several nutrients. Even one a day made a difference, noted Arab, a professor of epidemiology at the University of California, Los Angeles.

"Salad is a colorful, creative way to get nutrients that are in short supply in the U.S. diet," she told Reuters Health.

Arab did offer some caveats as to what constitutes a healthful salad. Color is key; dark leafy greens mingled with red and yellow vegetables beats iceberg lettuce and croutons.

"We are not talking about pasta or potato salad here," Arab added.

The findings should also help allay any concerns about the body's ability to absorb certain nutrients from raw vegetables, according to the researchers. Water-soluble vitamins, like vitamin C and many B vitamins, are heat-sensitive, and it's better to get them through raw vegetables, Arab explained.

But certain other nutrients, including the carotenoids, tend to be better absorbed from cooked vegetables.

However, a little fat helps the body get the most from these nutrients. And in this study, salad dressing was linked to higher nutrient levels in the blood -- suggesting, according to the researchers, that the oils in many dressing aided in absorption of some nutrients.

SOURCE: Journal of the American Dietetic Association, September 2006.