学习啦【其它健康常识】 编辑：立文 发布时间：2016-09-20
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.
f 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.
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.