"I eat a lot of hot peppers," she told CBS News anchor Katie Couric, who had asked her how she maintains her stamina on the campaign trail. "I for some reason started doing that in 1992, and I swear by it. I think it keeps my metabolism revved up and keeps me healthy."

Nutritionists say Mrs. Clinton may be on to something. Although the scientific study of hot peppers is limited, there are some suggestions that capsaicin, the active ingredient in peppers, has numerous health benefits.

For starters, peppers contain several important nutrients, including beta-carotene, lutein, zeaxanthin and vitamin C, said Jonny Bowden, a board-certified nutritionist and author of "The 150 Healthiest Foods on Earth." In fact, peppers contain about twice the amount of vitamin C found in citrus fruits, which may help explain why they have emerged as a popular home remedy for fighting colds

Much of the research on capsaicin involves pain relief, and capsaicin is a common ingredient in over-the-counter pain creams. The analgesic effect of the capsaicin found in peppers may help explain why Mrs. Clinton believes it makes her feel better.

"People on those kinds of schedules, they are wearing their body down and not sleeping much," Dr. Bowden said. ¡°Possibly it could be like taking a couple of aspirins."

Hot peppers also may slightly boost the metabolism, which could give Mrs. Clinton a sense of having more stamina and energy. "If you ate a big hot pepper, it would be hard to go right to sleep," Dr. Bowden said.