Travellers' Thrombosis - An Update
by Maurice McKeown, BDS, PhD
Who is at risk for DVT?
Air travel is associated with a definite risk of DVT. The extent of that risk is largely determined by the health of the individual and the presence of known risk factors.
Some of those personal risk factors are:
In this age of global everything, travel is a fact of daily life and health tourism is becoming ever more common. People are seeking medical treatment in far off lands where the treatment may be better or cheaper. It is well known that air travel after surgery carries with it a greater risk of thrombosis. After orthopedic surgery, particularly to the lower limb, the risks are particularly high. Now new research suggests that the risk is not confined to post operative situations; it is present in those who travel long distances by air to obtain surgical treatment. Researchers at the Mayo clinic have discovered that patients who traveled more than 5000 miles to receive surgery were 30 times as likely to develop blood clots in the 28 days after surgery as were local patients. Another study in the same issue concluded that the duration of the surgery (longer than 3.5 hours) was a critical increased risk factor.
How can one prevent DVT?
Nutrients, in the liquid sense, are a much more contentious issue. The conventional wisdom is that dehydration is to be avoided. Unfortunately there appears to be little evidence to suggest that tea and coffee contribute to it, as widely claimed. Last year a small study at Mount Everest base camp concluded, "that even when drunk at high altitude where fluid balance is stressed, there is no evidence that tea acts as a diuretic when consumed through natural routes of ingestion by regular tea drinkers, but that it does have a positive effect on mood." A review of caffeine consumption by athletes in 2002 came to similar conclusions. The study reviewed ten major investigations. It concluded that, "There is no evidence of a fluid-electrolyte imbalance that is detrimental to exercise performance or health." It noted that consumption of identical volumes of water and caffeinated beverages resulted in fluid retention of 81% in the case of water and 84% in the case of the caffeinated beverage.
Alcohol is also on the hit list of conventional advice. Red wine reduces platelet stickiness and is more likely to be beneficial than detrimental, if consumed in moderation. Consumption of beer and spirits also results in beneficial reduction of platelet stickiness. The key difference is that there is a rebound effect after beer and spirit consumption, which results in increased platelet adhesiveness that may be significant if larger quantities of alcohol are consumed.
The commonest fluid myth is of course the advice to drink copious amounts of water. This seems to be logical advice to combat dehydration. Yet I have been unable to find any supporting research. I should elaborate on the Japanese study I mentioned in my previous article. It was carried out by Japan Airlines Medical Services in 2002. Forty healthy men were placed in a pressure chamber to simulate a nine hour long-haul flight. The 40 male participants received either plain water or an electrolyte solution at regular intervals. The electrolyte beverage, called Pocari, contained sodium and potassium (roughly in the ratio 4:1) and carbohydrate. Regular urine samples were taken. The researchers concluded that those who drank the electrolyte fluid had a greater net fluid balance at the end of the simulated flight than those who were drinking plain water. The electrolyte subjects were "also less likely to show an increased thickness in blood from their legs."
Can nutrition provide protection?
Proprietary products for DVT prevention
Zinopin is a supplement developed by UK surgeon John Scurr, containing 100 mg of pycnogenol and 150mg of ginger (www.zinopinusa.com)
Pinokinase was developed by Neil Riordan, a DVT victim, and contains pycnogenol and nattokinase (www.flitetabs.com)
There are other natural clot inhibiting compounds available, but they do not seem to have been targeted to prevent travellers' thrombosis; e.g. lumbrokinase (Boluoke) (http://canadarna.com)
Readers may intuitively presume that nature may have more to offer than big Pharma. Perhaps it is the ultimate irony that the ultimate natural medicine aspirin has become the ultimate recourse of mainstream medicine in the treatment and prevention of so much, in spite of its limitations.
Most commercial anti-thrombosis products are relatively expensive and concerned travellers may wish to consider a combination of grape seed extract (equal to or better than pine bark products) and nattokinase as a DVT therapy. Both are available through the IHN web store (www.yourhealthbase.com/vitamins.htm).
Dr Johnson did say, "It is better to travel hopefully than it is to have arrived." Perhaps he was right!
On my next brain-bending trip from New Zealand to Europe I shall be consuming a grape seed/nattokinase combination washed down with an electrolyte drink.