But study did not determine how much was consumed, and only found an association, not cause-and-effect link.

(HealthDay)—Consumption of chamomile may be linked to a longer lifespan for older Mexican-American women, new research suggests.

The study, funded by the U.S. National Institutes of Health, found that among Mexican-American women who consumed , the risk of death during the study period was reduced by about 28 percent.

"Drinking chamomile tea is beneficial to the health of Mexican-American women," said the study's lead author, Bret Howrey, assistant professor of family medicine at the University of Texas Medical Branch in Galveston.

However, the study only showed evidence of a possible link between chamomile and longer lifespan. It didn't prove a cause-and-effect relationship.

And at least one nutritionist questioned the validity of the study's findings.

The herb chamomile is a mainstay of alternative medicine, and practitioners often recommend it to treat conditions like stomach problems and cramps, according to the study. But "few well-designed and controlled human studies have been conducted on the effects of herbal teas or herbal preparations," said Diane McKay, an assistant professor with the Friedman School of Nutrition Science and Policy at Tufts University, who's familiar with the study findings.

Researchers examined the findings from almost 1,700 Mexican-American people from the southwest United States. They were all 65 and older, and were tracked from 2000 to 2007. About 14 percent of the participants reported using chamomile, according to the study.

Using chamomile didn't seem to affect lifespan in men, the study found.

When researchers adjusted the statistics to account for factors such as age, smoking and , they found the odds of dying during the study period were reduced by just over one-quarter in women who used chamomile.

Why might chamomile affect lifespan and health in general? It's unclear. "Our understanding of chamomile is still really in its infancy," Howrey said.

He added that the study itself has limitations: It's based entirely on research into a Mexican-American community. Only 26 percent of those in the study had a normal weight. Also, there's no information on the overall diet of the participants. Those who consumed chamomile could have healthier diets overall, although the researchers did try to take factors such as fitness and weight into account.

The study also says nothing about people who aren't Mexican-American, Howrey said. And he noted that the study doesn't eliminate the possibility that men could benefit from chamomile. The study may not have picked up a benefit for them due to lower rates of chamomile consumption (just 8 percent of men reported using it) or worse health overall, he said.

McKay called the study "deeply flawed." She said the findings don't support the idea that chamomile affects lifespan.

Among other weaknesses, she said, the study doesn't explain how participants consumed chamomile: "We can't say for sure whether these folks actually drank the same chamomile tea we find on our store shelves, or even how much they drank and how often. No information was collected on the actual form of chamomile used, i.e., whether it was tea, pill or other type of preparation, or whether it was actually consumed rather than used as a lotion or inhaled oil, for example."

Howrey acknowledged that the study says nothing about how much chamomile to take. Still, he recommends consuming chamomile, especially since it's "generally non-toxic, relatively inexpensive, and widely available."

He mentioned one caveat—some people may be allergic to chamomile, especially if they're allergic to related plants such ragweed.

Howrey said the researchers are continuing to track the older Mexican-Americans. However, "if the effects of brewed chamomile are very subtle and benefits slow to manifest," a more extensive study would be needed, he said.

The study was published recently in the journal The Gerontologist.

More information: For more about chamomile, try the National Center for Complementary and Integrative Health.

Journal information: The Gerontologist