A weekly round-up of news affecting your health:
A diet rich in fibre can protect against the flu, a new study suggests.
Australian and Swiss researchers, led by Professor Benjamin Marsland of Monash University, have shown in mice that fibre fermented in the gut countered influenza A, which is one of the most common viral diseases.
Prof Marsland says the fermented fibre protects against the flu by prompting the immune system to produce cytotoxic T cells, which kill cells that are infected with the virus.
"What is produced in the gut doesn't just change what's in the gut," Prof Marsland said.
"It goes into the circulation and changes the immune system at one of the most fundamental levels, the bone marrow, where a lot of our immune cells develop."
Previous research had shown that mice fed a diet high in fermentable fibre protected against asthma.
The findings, published in the journal Immunity, have raised the possibility of a specialised fibre supplement to improve the efficacy of the flu vaccine.
Women who exercise for more than 35 minutes a day late in their pregnancy are less likely to require an emergency caesarean section, a Norwegian study has found.
The Norwegian Fit for Delivery study involved more than 600 women and analysed the impact of exercise and dietary intervention during pregnancy.
One group of 303 women took park in twice-weekly exercise classes and received dietary counselling, while the other group of women received standard care.
The findings, published in the journal Acta Obstetricia et Gynecologica Scandinavica, showed the women from the exercise and dietary intervention group had a slightly longer first stage of labour.
Women reporting to be highly active (more than 35 minutes of moderate-to-vigorous physical activity a day) in late pregnancy had a reduced risk of having an acute caesarean section compared with those with the lowest physical activity level.
"The association between physical activity level and mode of delivery might help motivate more women to engage in regular physical activity before and during pregnancy, which in turn will give additional health benefits for the women and their babies," said lead author Dr Birgitte Sanda, of the University of Agder, Norway.
Men with highly physical jobs are at greater risk of dying prematurely than inactive workers, a new study has shown.
International guidelines encourage people to engage in up to 30 minutes of at least moderate intensity physical activity daily but they do not distinguish between occupational, leisure-time and transportation-related activity.
Recent research, though, suggests a "physical activity paradox", in which high levels of occupational physical activity can have a detrimental impact on health.
A team of international researchers carried out a systematic review of evidence regarding the association between occupational physical activity and all-cause mortality.
The study of more than 193,000 people, published in the British Medical Journal, showed men with high-level occupational physical activity had an 18 per cent higher risk of early death compared with men engaging in low-level occupational physical activity.
This was still the case even when levels of leisure time physical activity were taken into account.
No such association was observed among women.
"The results of this review indicate detrimental health consequences associated with high level occupational physical activity in men, even when adjusting for relevant factors (such as leisure-time physical activity)," the authors wrote.
"This evidence indicates that physical activity guidelines should differentiate between occupational and leisure-time physical activity."