Almost four million people in China over the age of 50 are likely to die from diseases caused by passive smoking, based on a British study of more than 15,000 non-smokers in Guangzhou. Chronic bronchitis and emphysema probably will account for half the deaths, and lung cancer and heart disease the rest, AFP reports. 'We're looking at something like 100,000 people dying a year from passive smoking,' says co-author K.K. Cheung of Birmingham University. Passive smoking costs China about 29 billion yuan annually in medical costs, according to a Beijing University study.

Seed of hope for hot flushes cure

Flaxseed may help reduce the incidence of menopausal hot flushes by as much as half, based on a small, six-week preliminary Mayo Clinic study. The women involved in the study ate two tablespoons of ground flaxseed, twice a day, with cereal, juice, fruit or yogurt. Side effects included abdominal bloating and mild diarrhoea, WebMD reports.

Healthier prostates in tippling mice

A glass or two of red wine a day may help reduce the risk of prostate cancer, based on a University of Alabama study of mice. Male mice fed resveratrol, a compound found in red wine, were as much as 87 per cent less likely to develop the most deadly type of prostate cancer. Those that developed cancer had less serious tumours, which were more likely to slow or stop, AFP reports. The study 'adds to a growing body of evidence that resveratrol consumption through red wine has powerful chemo-prevention properties, in addition to apparent heart-health benefits', says team leader Coral Lamartiniere.

Weight impact on testicular cancer

Men who were either overweight or underweight when they were born appear to be at greater risk of testicular cancer - although Harvard Medical School researchers aren't sure why. They analysed 13 studies published between 1983 and 2004 of more than 5,500 men with testicular cancer, Reuters reports. Those whose birth weight was less than 2.5kg were 18 per cent more likely to develop the cancer; and those whose birth weight was more than 4kg were 12 per cent more likely.

Bad memories good for survival

People tend to recall bad memories more easily and in greater detail than good ones - and probably for good evolutionary reasons, say Boston College psychologists. Brain scans show that negative emotions such as fear and sadness boost activity in the area linked to memories, WebMD reports. From an evolutionary viewpoint, 'it's logical that attention would be focused on potentially threatening information', the researchers say.

Jason Sankey is a tennis professional