Among all cancers, lung cancer is the biggest killer: more than 100,000 Americans die of the disease each year. Giving up smoking is one way to reduce the risk, but another answer may lie in the kitchen, according to a report in British medical journal The Lancet. Since 1957, a team of researchers has monitored the dietary habits and medical histories of 2,000 middle-aged men employed by the Western Electric Co. in Chicago. Led by Dr. Pritichard Shekelle of Chicago's Rush--Presbyterian--St. Luke's medical Centre, the team recently began to sort out the links between the subjects' dietary patterns and cancer. Other animal and human studies has suggested that vitamin A might offer some protection against lung cancer, but did not distinguish vitamin A made in the body from that in carotene (胡萝卜素), which is abundant in a variety of vegetables and fruits, including carrots, spinach, broccoli, squash, tomatoes and apples. The Western Electric study showed little correlation (相互关系)between the incidence of lung cancer and the consumption of foods containing performed vitamin A. But the data on carotene intake (摄入)revealed a significant relationship. Among the 488 men who had the lowest carotene consumption, there were 14 cases of lung cancer in a group of the same size that ate the most carotene, only two eases developed. The apparent protective effect of carotene held up even for long-time smokers. Further studies will be necessary before the link between lung cancer and carotene can be firmly established. Meanwhile, researchers warn against taking large amounts of vitamin-A supplements, which can be extremely poisonous in high doses. Instead, they advise a well-balanced diet that includes foods rich in carotene. Vitamin A can be found in meat.