Updated

To the likely delight of nagging parents, a new study shows that people who eat more fruit and veggies tend to live longer.

Plants from the mustard family -- including broccoli, cabbage, and cauliflower -- seem particularly beneficial, although the study can't prove that eating more vegetables automatically increases longevity.

It's possible, for instance, that those who consume lots of produce also have a healthier lifestyle in general.

Still, the findings "provide strong support for the current recommendation to increase vegetable consumption to promote cardiovascular health and overall longevity," study researcher Dr. Xianglan Zhang, of Vanderbilt University School of Medicine in Nashville, Tennessee, told Reuters Health.

Mustard-family vegetables are high in vitamin C and fiber and also contain other nutrients that may have health benefits.

The study, published in the American Journal of Clinical Nutrition, is based on a survey of nearly 135,000 adults from Shanghai, China.

Participants filled out questionnaires about their eating habits and health history, and the researchers then divided them into five categories according to how much produce they ate.

Over five years, four percent of the people died. Those who downed the most vegetables or fruits, however, were 15 percent less likely to die over that period than those who ate the fewest.

For mustard-family vegetables, there was an even bigger difference in death rates between people with high and low intakes.

The researchers found a similar pattern when they looked at people dying from heart disease -- about a quarter of all deaths in the study. But there was no evidence that eating fruits and vegetables was linked to cancer risk.

According to Dr. Lydia Bazzano, who was not involved in the study, the results are promising. But they don't prove that just eating more fruit and vegetables will necessarily make people live longer.

"Unmeasured health habits may account for some of the association,"
Bazzano, of Tulane University Health Sciences Center in New Orleans, told Reuters Health.

The researchers did try to rule out alternative explanations -- such as age, weight, exercise, vitamin use, and smoking -- but acknowledge there could be more factors at play.

Still, they encourage people to eat more produce, especially vegetables from the mustard family, as a step toward living longer, healthier lives.

Heart disease is the leading killer worldwide, causing more than 600,000 deaths every year in the U.S., according to the Centers for Disease Control and Prevention. The CDC recommends eating two to four cups of fruit and vegetables daily.