Even though ulcers appear to run in families, lifestyle plays more of a role than genetic factors in causing the illness, according to a report in the April 13th Journal of Internal Medicine.
In particular, smoking and stress in men and the regular use of pain releasing medicines in women were linked with an increased risk of developing all ulcers.
Overall, 61% of ulcer risk appears to be due to environmental factors, such as smoking, and the remaining 39% is due to genes according to Dr. Ismo Raiha of the University of Turky and colleagues at the University of Helsinki, Finland. Some researchers had suggested that families may spread Helicobacteria pylori, the bacteria that can cause ulcers. However, the new study suggests this is unlikely, according to the report.
Raiha and colleagues studied data from more than 13,000 pairs of twins "to examine the roles of genetic and environmental factors in the origin of peptic ulcer disease", they explain. Both twins were more likely to develop an ulcer if the pair were genetically the same as compared with a pair of fraternal twins, suggesting that there must be some genetic susceptibility to ulcer development.
However, the risk was no greater in twins living together compared with twins living apart, suggesting that shared exposure to H. pylori (幽门螺旋杆菌) was not to blame. "
Environmental effects
were not due to factors shared by family members, and they were related to smoking and stress in men and the use of analgesics in women," the authors wrote. "The minor effects of shared environment to disease liability do not support the concept that the grouping of risk factors, such as H. pylori infection, would explain the genetic factor of peptic ulcer disease," they concluded.
单选题
According to the passage, which of the following is a very likely cause of ulcer in men?
【正确答案】
A
【答案解析】[解析] 因第二段中提到“smoking and stress in men...”，其他各项均与文中内容不符。故选A。
单选题
What factors contribute to over half the ulcers?
【正确答案】
C
【答案解析】[解析] 第三段第一句提到：“Overall, 61% of ulcer risk appears to be due to environmental factors...”，故选C。
单选题
In relation to ulcers, experts study twins in order to examine
【正确答案】
C
【答案解析】[解析] 第四段谈到这项研究的目的，即“examine the roles of genetic and environmental factors...”，故选C。
单选题
"Environmental effects" in the fifth paragraph refers to effects brought about by ______.
【正确答案】
B
【答案解析】[解析] 第五段明确指出“they were related to smoking and stress in men and the use of analgesics in women”，故选B。
单选题
The passage argues that ______.
【正确答案】
B
【答案解析】[解析] 从全文看，文章主旨在第一段已提出，即“...lifestyle plays more of a role than genetic factors in causing the illness”，故选B。