Health: Eat, drink and be merry, but not on a plane

Coffee, tea or milk? Stewards will have to learn a new line if two new studies on air travellers' health are correct. They would also have to add health warnings to the routine lifejacket demonstration.

A British House of Lords report following a nine-month inquiry advises that most air travellers should abstain from alcohol and caffeine before and during flights if they want to reduce any risk of collapsing with a blood clot.

The study called for the mandatory safety demonstration given to passengers before take-off to be followed by advice on avoiding blood clots, the Independent reported.

The committee recommended that travellers most vulnerable to deep vein thrombosis (DVT) - anyone over 40, pregnant women or those on the pill - should avoid drinking alcohol, tea or coffee at the airport or on board. They should also avoid sleeping for long periods in their plane seats.

All passengers should be encouraged to move around the cabin and take part in "preventive leg exercises."

Britain's lawmakers called for seat space and leg room to be increased "to a healthy minimum," and welcomed research by their Civil Aviation Authority into whether the minimum distance of 71cm between the backs of seats should be increased.

Airlines told the committee that increasing seat pitch by 5.8cm would raise fares by about 10 per cent.

The report found no evidence to support two common complaints about flying: that the quality of cabin air had fallen since the introduction of recirculatory ventilation systems, and that risks of cross-infection between passengers were greater than in other crowded situations.

According to the BBC, Japanese research suggests that eating before takeoff can help the body's blood to circulate more easily and reduce risks of serious illness.

The doctors used a simulator to study the effects of flying on 12 volunteers at 3000 metres. They measured heart function, blood flow and the supply of oxygen to the brain and other organs after the volunteers had fasted for 12 hours.

The doctors found that, after fasting, heart function and blood flow volume remained the same in the volunteers.

However, the effects of reduced cabin pressure caused blood pressure to fall and the level of oxygen in the organs and the brain to drop significantly.

The tests were repeated after the volunteers had eaten and drunk, and the doctors found that eating and drinking increased cardiac output and blood flow to the brain.

They believe these increases could protect many passengers from becoming ill during a flight.