When it comes to travel and your health, the term "flight plan" means more today than just the fastest way from Toronto to Tokyo. Health experts are now advising people who plan to fly, to talk to their doctors beforehand about how air travel may affect their health, particularly if they have risk factors for certain ailments or diseases.

Front and centre is the problem called economy class syndrome, formally known as DVT for Deep Vein Thrombosis, a potentially fatal condition.

In September 2000, a 28-year-old woman perished in Britain after disembarking from an economy class seat, where she had sat for a 20-hour journey.

 DVT is a leading cause of death and occurs in about two in 1,000 people. Clots form when circulation slows, usually as a result of people sitting in the same position for too long.

 According to a recent issue of The University Of Toronto's Health News, some people have a slightly higher risk of DVT: Those who are obese, smoke, use birth control pills or who have a history of forming blood clots.

 But those squashed seats that force your knees practically up to your chin can't help. Economy class is to air travel what steerage was to steamships. Every inch of space is given up and the comfort of the passenger -- including his health -- ignored.

 According to a recent issue of the Johns Hopkins medical letter Health After 50, the explanation behind DVT is a simple one. When you move your lower limbs, muscle contractions keep the deep vein blood flowing back to the heart by compressing the walls of the veins. When your legs are immobile for too long, clots can form. When part of a clot breaks off and travels up through the right side of the heart to pass through the pulmonary artery into the lung, where the arteries become tinier, clots can get stuck. The result is reduced blood flow, chest pain, shortness of breath, lung damage and perhaps even death.

 But since an estimated one billion people fly each year, some health experts have questioned the validity of such a thing as economy class syndrome. After all, they say, people sit immobile for hours at work or, when ill, in bed. Not all immobile people drop dead from DVT.

 "I don't believe this is a problem related to the airplane or the airline," Dr. John Scurr, a British vascular surgeon told Associated Press. "It may be that sitting in front of your computer for hours does the same thing."

 To further investigate this scary syndrome, Scurr and his colleagues conducted the first scientific experiment to explore a possible link between cramped seating on long flights and potentially deadly blood clots. Their study results were published just a few weeks ago in The Lancet, a prestigious British medical journal.

 Though tiny clots in the calf veins of about 10% of passengers who flew for more than eight hours were discovered by the team, most of the clots seemed to dissolve routinely on their own in the people's bodies. Most did not progress to do major damage.

 However, about 10% of the above 10% were on their way to becoming killer clots -- a very small number, but a number that signified a possible co-relation between blood clots and flying. The study involved 200 people over the age of 50 who flew out of London's Heathrow Airport on flights lasting at least eight hours. Half the passengers were given surgical-type compression kneesocks to wear on their flights.

 None of those who wore the stockings developed a clot. Twelve of the 116 who did not receive the stockings had a clot, but the clots were either treated or dissolved on their own.

 The significance of the study was that it provided a heads-up for travellers.

 "This is really about a change in our habits," Scurr said. "There has been a general realization recently that people get on planes, drink far too much and just sleep -- all bent up. That's all we've been drawing attention to here."

 Whether you get blood clots or not, there's no disputing the fact that economy class is a crush. In the past year, as more and more DVT stories hit the press, charges have been made (and some lawsuits launched) that airlines are neglecting the health of passengers.

 Last year, in Britain, a House of Lords Science and Technology Committee recommended that airlines include health warnings with long-haul tickets, provide "air travel and health" display cards at ticket point-of-purchase spots, and provide health briefings as part of the pre-flight safety drill.

 But why not just redesign the seats with safety and comfort in mind?

 A recent report in Conde Nast Traveler Magazine introduced Richard Seymour and Richard Powell, two British industrial designers who have come up with a solution to the torture of coach but who have not yet been able to convince airline companies to buy into the radical seat concept.

 Recognizing that the more people airlines squeeze into a flying box, the more profitable it is for them, so the partners simply redesigned the economy class seat (traditionally 17 to 18.5 inches wide with as little as nine inches legroom).

 The Seymour Powell seats folded up (to improve access) and were made with air bladders under the back of the thigh area which can be inflated to ease pressure and help counteract restricted blood flow.

 A similar inflatable air pillow built into the seat provides lower back support. The seat also adapts to the body's shape hammock-style and the headpiece slides up and down according to the height of the person seated. It is also lighter than conventional seats, which is a plus in that lighter seats save fuel costs.

 To be sure, cramped seating is a worry and people should be aware that blood clots can be fatal. But Dr. Mark Wise, a family physician who directs Thornhill's Travel Clinic, believes there's much that passengers can do but don't do to protect their health -- even if they're flying economy.

 "I think people should be looking after themselves better on a plane. You sit for six hours and it makes no sense to just eat and eat and drink alcohol. I think you've got to feel better by just stretching occasionally. In the course of a normal day we do that."

 Treat yourself well, says Wise, who is not referring here to having an extra vodka and orange juice. "It's really more a question of comfort than of dying from a blood clot."

 The snag of jet lag

 Though the chances of having a serious in-flight medical emergency are rare, you are likely to experience some form of jet lag if you've crossed a time zone or two.

 How to reset your inner clock so that jet lag doesn't spoil your fun?
 

• Three days before your trip, go to bed and get up earlier if you're travelling east; later if you're travelling west. Experts at the Mayo Clinic suggest booking a flight that arrives in the late afternoon, then staying up until 10 p.m. local time. To help rest your biological clock, soak up as much bright light as you can during this time.
   
• According to The University Of Toronto's Health News, asking your doctor to prescribe a short-acting sleeping medication to help you fall asleep during the flight or at your new bedtime may help you get back in sync more easily.
   
• Melatonin, a natural hormone produced by the pineal gland, is a good treatment for jet lag and insomnia, says pharmacists Earl Mindell, author of Earl Mindell's Supplement Bible. He recommends taking it about half-an-hour before going to sleep at your new destination.
  
   Comfort at 30,000 feet
  
   Fear of flying, air rage, claustrophobia, dehydration and intestinal gas are definitely more common than blood clots, experts say. Some of air travel's greatest health hazards include the following. So beware and take care:
   
• Achoo! Infectious diseases such as colds are definitely transmitted within airplanes, where at least some of the air is recirculated. "Four-hundred people in an airplane for eight hours means you've a greater chance of being exposed to something," says Dr. Mark Wise. "But you can also get a cold if someone is coughing all over you in the waiting lounge." Prevention tips: Wash your hands thoroughly when you use the washroom; carry a hand sanitizing product.
   
• All gassed up: "As we ascend, the pressure in a cabin falls," explains Wise. "The volume of trapped gases also goes up, which is why we get bloated." What to do? Avoid eating leafy vegetables, but drink lots of water. (Experts also advise anyone to postpone their trip if they've had recent abdominal, eye, chest or central nervous system surgery.)
   
• Be prepared: Plan ahead if you have special health concerns. Diabetics, for instance, need to consider time changes and flight delays. They should keep medication close by and wear a medical ID tag or bracelet.
  
   If you're flying with a cast, make sure your doctor knows so that the cast is either removable or loose enough to allow for any expanded air that gets trapped between the cast and your skin. Because you should keep your leg elevated while in a cast, try for a bulkhead seat.
  
   Scuba divers should know to wait at least 12 to 24 hours after their last dive to fly. The Mayo Clinic warns that pressure changes in airplanes can give scuba divers the bends.
   
• Carry-ons: Experts advise you to keep most of your medications with you instead of checking them with your baggage. To minimize discomfort from flying, the Mayo Clinic suggests adding these items to your carry-on bag: Decongestant medication to avoid ear and sinus discomfort (nasal sprays can be a great short-term fix); chewing gum (handy for relieving ear discomfort during take-off and landing); bottled water (to keep you hydrated in case your flight attendant is too busy to heed your request); moisturizing lotion and lip balm to combat the effects of dry air.
   
• Research: For information on vaccinations and health hazards, plus general health tips, take a peek at Dr. Mark Wise's Web site, http://www.drwisetravel.com/, and its links to the world's most credible travel health sites.
  
   
• More travel tips available Here
   
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