Sunday, January 8, 2012

The secret to good health

Medical research is incremental by design and most of what it discovers is both obscure and largely irrelevant to the lay public. The studies that are picked up by the news media are often startling in a predictable fashion, but can usually be safely ignored. In most cases they are part of a long series of research projects that circle around endlessly in some scientific cul-de-sac, dipped ino occasionally by some nosy journalist.
For example: Is coffee consumption good or bad for you? It doesn’t seem it should be that hard to figure this out, yet every few months some group of scientists reaches a conclusion that appears to contradict what was previously reported. I’m voting in favor of the world’s most popular stimulant having a net positive effect on our health. And if some day it should be proved that coffee is unhealthy, I will mourn the occasion—and pour myself another cup of joe.
The same sort of confusion arises among researchers who attempt to discern the effects of exercise on people diagnosed with melanoma. While several studies have indicated that moderate exercise helps to stimulate the immune system, there is also evidence that some extreme sports, such as marathon training, can have the opposite effect. Just because something fosters overall health doesn’t mean you can’t get too much of a good thing. Just to be safe, I neither run marathons any more nor drink more than two or three cups of coffee a day.
A recent study that seems to confirm the obvious indicates that the outcome for patients diagnosed with advanced melanoma is linked to their overall health. It's not how old but how frail you are that best predicts how you’ll fare after a diagnosis of melanoma. In fact, young patients in poor health may have worse outcomes than older patients in good shape. On the age continuum, I am much closer to being an “older patient” than a young one, but am also in pretty good physical shape.
A study from the University of Michigan Comprehensive Cancer Center found that patients with decreased core muscle density were more likely to see their cancer spread to distant parts of the body. The study looked at 101 patients treated for stage III melanoma at the cancer center. Researchers examined CT scans for each patient to measure the area and density of a core muscle called the psoas, which runs along both sides of the spine.
They found that patients with lower muscle density had significantly higher rates of their cancer returning regardless of factors such as the size of the tumor or the patient's age. Every 10 units of decreased muscle density translated to a 28% increase in recurrence. In addition, frailer patients had more complications from surgery to remove their cancerous lymph nodes.
Like most studies of its type, this one parses the data in eye-glazing detail. What I find interesting is the conclusion reached by the researchers that responses to melanoma therapy is superior among those who are healthiest. The previously published data on the outcome of specific therapies may, therefore, significantly underestimate the potential upside among those patients who are fittest. Assuming that muscle density is a useful surrogate for overall health, I can risk the opinion that the dismal survival statistics for advanced melanoma are marginally less dire for those, figuratively speaking, with strong backs and good lungs. It also helps in this case to be older, as cancers in young people tend to be more aggressive.
Many patients by the time they get to drug therapies for their metastatic melanoma are already very sick. Some were unfit even before they were diagnosed with cancer. Another line of scientific inquiry has shown that obesity is highly predictive for many forms of cancer, although not for melanoma. The take-away message from all of this for me is not to place undeserved confidence in one or even a series of research studies, but to be encouraged that science will sometimes confirm our common-sense conclusions: coffee is good for us, and so is exercise—so long as you don't overdo it. Being a fit coffee-drinker may yet prove to be my best hope for healthy living.

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