大学三分钟英语演讲稿

Soy food good for women

Women who ate soy regularly as children have a lower risk of breast cancer, American researchers report. And men who eat fish several times a week have a lower risk of colon cancer, a second team of researchers have told the American Association for Cancer Research.

The studies add to a growing body of evidence about the role of diet in cancer. Cancer experts now believe that up to two-thirds of all cancers come from lifestyle factors such as smoking, diet and lack of exercise.

The US National Cancer Institute and researchers at the University of Hawaii found that women who ate the most soy-based foods, such as tofu and miso, when aged 5 to 11, reduced their risk of developing breast cancer by 58 per cent. It was not clear how soy might prevent cancer, though compounds in soy called isoflavones have estrogen-like effects.

A second study showed that men who ate fish at least five times a week had a

40 per cent lower risk of developing colorectal cancer compared with men who ate fish less than once a week.

Many kinds of fish are rich in omega-3 fatty acids, which interfere with the cyclooxygenase-2 or COX-2 enzyme. COX-2 affects inflammation, which may play a role in tumour growth.

据美国研究人员报告，儿童时期经常吃豆类食品的女性患乳腺癌的风险较小。另一组研究人员则向美国癌症研究协会提出，一周吃几次鱼的男性患结肠癌的几率较小。

这两项研究进一步证明了饮食对于防癌的作用。癌症防治专家认为，在所有种类的癌症中，多达三分之二都是由吸烟、节食及缺乏锻炼等不健康的生活方式造成的。

美国全国癌症研究所和夏威夷大学的研究人员发现，在5岁至11岁时经常吃豆腐、味噌等豆类食品的女性患乳腺癌的几率要低58%。至于豆类食品为什么可以防癌还不清楚，不过大豆中所含的名叫异黄酮的化合物具有雌性激素的作用。

另一项研究表明，一周吃鱼至少五次的男性患结肠癌的风险要比那些一周都吃不到一次鱼的男性低40%。

很多鱼类中所富含的Omega-3脂肪酸能够抑制环氧化酶2的活性。环氧化酶2会引起发炎，这可能会刺激肿瘤的生长。

If you're middle-aged and your memory's not what it used to be, check the bathroom scale, researchers warned, suggesting overweight people tend to score more poorly on tests of memory than their thinner peers do.

The findings suggest that a heavier weight in middle age may mean a higher risk of dementia later in life.

Reporting in the journal Neurology, the researchers speculated that higher rates of cardiovascular disease or diabetes might help explain the link. But it's also possible that substances produced by fat cells, such as the hormone leptin, have direct effects on the brain.

The study compared mental abilities to body mass index (BMI), a measurement of weight in relation to height used to define overweight and obesity. A BMI of 25 or more indicates overweight, and 30 or more is obese.

The study also investigated the relationships between BMI and cognitive function in 2,223 healthy men and women between the ages of 32 and 62 in France through the use of four cognitive tests.

The study found a higher BMI was associated with lower cognitive test scores. Results from a test involving word memory recall show people with a BMI of 20 remembered an average of nine out of 16 words, while people with a BMI of 30 remembered an average of seven out of 16 words.

研究人员提醒，如果你已步入中年，发现自己的记忆力不如从前，那么你得小心体重了。研究表明，超重的人记忆测试的得分要比较瘦的人低。

研究发现，体重偏大的中年人今后患老年痴呆症的可能性较大。

研究报告在《神经学》期刊上发表，研究人员推断，心血管疾病及糖尿病的高发现象可以解释其中的原因。此外，脂肪细胞所产生的物质，如瘦体激素，对大脑有直接影响。

此项研究将调查对象的智力与体重指数进行了对比。体重指数指的是身高和体重之间的比例，主要用来衡量一个人是否偏胖或肥胖。体重指数为25或25以上的人偏胖，达到30或30以上的人则为肥胖。

研究人员还对体重指数和认知功能间的关系进行了研究，他们在法国对2223位年龄在32岁至62岁间的健康男女进行了认知测试。

研究发现，体重指数越大，认知测试的得分越低。其中一项"单词记忆"的测试结果表明，在16个单词中，体重指数为20的人平均能记住9个，而体重指数为30的人平均只能记住7个。

People who do not get enough sleep are more than twice as likely to die of heart disease, according to a large British study released Monday.

Although the reasons are unclear, researchers said lack of sleep appeared to be linked to increased blood pressure, which is known to raise the risk of heart attacks and stroke.

A 17-year analysis of 10,000 government workers showed those who cut their sleep from seven hours a night to five or less faced a 1.7-fold increased risk of death from all causes and more than double the risk of cardiovascular death.

The findings highlight a danger in busy modern lifestyles, Francesco Cappuccio, professor of cardiovascular medicine at the University of

Warwick's medical school, told the annual conference of the British Sleep Society in Cambridge.

"A third of the population of the UK and over 40 percent in the US regularly sleep less than five hours a night, so it is not a trivial problem," he told reporters.

Previous research has highlighted the potential health risks of shift work and disrupted sleep. But the study by Cappuccio and colleagues, which was supported by British government and US funding, is the first to link duration of sleep and mortality rates.

The study looked at sleep patterns of participants aged 35-55 at two points in their lives - 1985-88 and 1992-93 - and then tracked their mortality rates until 2004.

The results were adjusted to take account of other possible risk factors such as initial age, sex, smoking and alcohol consumption, body mass index, blood pressure and cholesterol.

Cappuccio said it was possible that longer sleeping could be related to other health problems such as depression or cancer-related fatigue.

"In terms of prevention, our findings indicate that consistently sleeping around seven hours per night is optimal for health," he said.

(Agencies) 本周一公布的一项大规模英国调查表明，睡眠不足的人死于心脏病的几率是睡眠充足者的两倍多。

目前其中的原因尚不清楚，但研究人员称，睡眠不足会导致血压升高，从而增大患心脏病和中风的风险。

一项针对1万名政府职员、长达17年的跟踪调查表明，每晚睡眠时间从七个小时减少到五个小时或更少的人因各种原因而死亡的几率是睡眠正常者的1.7倍，而且死于心血管疾病的风险也增加了1倍多。

沃里克大学医学院的心血管药物学教授弗朗西斯哥?卡普西奥在英国睡眠学会在剑桥召开的一年一度的研讨会上说，这一研究成果揭示了忙碌的现代生活中潜在的危险。

他在接受记者采访时说：“三分之一的英国人以及超过40%的美国人每晚的睡眠时间常常达不到五个小时，所以这个问题不可小视。”

此前有调查发现轮班及睡眠中断会对健康产生潜在威胁。但卡普西奥及其同事的这项调查则首次揭示了睡眠时间长短与死亡率之间的关系。该调查由英国政府和美国基金提供资助。

该调查对年龄在35岁至55岁之间的人在1985年至1988年以及1992年至1993年两个阶段的睡眠模式进行了探究，并对这一人群截至2004年的死亡率进行了追踪。

调查还考虑到了调查对象的初始年龄、性别、是否吸烟喝酒、体重指数、血压及胆固醇指标等其它可能的风险因素。

卡普西奥说，睡眠时间过长也可能导致如抑郁症及癌因性疲乏等其它健康问题。

他说：“就预防而言，我们的研究结果表明，每晚睡眠时间持续保持在七小时左右最益于身体健康。”