Tuesday, April 26, 2005

Sue Dunlevey confuses scepticism with cynicism

The fallacy of exaggerated conflict - the advocate claims that because there is some degree of uncertainty in a domain of knowledge, nothing at all is certain. Dunlevey, in her piece The newest health fad is ... scepticism:

…new research has debunked many of the hotly held preventative health tenets. …Governments, doctors and every major health body in the country wants us to lose weight, our weight problem is referred to as an epidemic. But just this week the Journal of the American Medical Association carried an article that found you are more likely to die if you are underweight than if overweight. Being overweight can increase your chances of survival.

For decades we've been told to slip, slop, slap and keep our skin out of the sun to prevent skin cancer. Well, new research by Associate Professor Rebecca Mason at Sydney University shows the vitamin D our skin makes when it is exposed to the sun may actually help protect us against skin cancer. We need regular, small doses of sun to build up protection against skin cancer, and we're not getting it. Professor Mason says we need five to seven minutes with our arms and face uncovered in the sun each day outside the danger time of 10am to 3pm.

And so Dunlevey continues, exaggerating other conflicts until she concludes:

…The more you reflect on the findings of health scientists the more my mother's wise advice seems to be true. "Everything in moderation" is her motto and that, in essence, seems to be what millions of dollars in scientific research has discovered about dieting, alcohol consumption, exercise and even exposure to the sun.

I.e., All that scientific research is a waste of time. Of course, she completely disregards what the research is actually saying. For example, here is the conclusion from the Journal of the American Medical Association paper:

Underweight and obesity, particularly higher levels of obesity, were associated with increased mortality relative to the normal weight category. The impact of obesity on mortality may have decreased over time, perhaps because of improvements in public health and medical care. These findings are consistent with the increases in life expectancy in the United States and the declining mortality rates from ischemic heart disease.

This conclusion hardly goes against the Governments, doctors and major health bodies that want us to lose weight. I'm quite certain I've never stumbled across advice suggesting it's healthy to be underweight - merely that it's unhealthy to be overweight.

Her paragraph on skin cancer is so riddled with erroneous reasoning that I can hardly be bothered. But persist I will, with one small point. Professor Masson's study advises five to seven minutes outside of the… "danger time". So, in what way is this contradictory to advice given by skin cancer experts?

Dunlevey tries to paint a picture of contradictory advice given by health experts. But when one actually looks at the fine print, it is clear that the advice is not contradictory, but rather, specific and detailed. But details are boring compared to conflict.

Now, should I go and have a second helping of dinner, or skip breakfast and lunch tomorrow? And where's my hat...