Concussions May--Or May Not--Be Bad For You

The mighty "may" strikes again. This time Dr. David C. Viano, of the National Football League's research committee on concussions, used a form of the word to hedge a dubious argument that concussions suffered by high school football players may not be as serious a health concern as is generally thought.

Here's the relevant section from a New York Times article by Alan Schwarz (March 1, 2007):

. . . [In a 2005 article in Neurosurgery] the committee wrote in its conclusion: “It might be safe for college/high school football players to be cleared to return to play on the same day as their injury. The authors suggest that, rather than blindly adhering to arbitrary, rigid guidelines, physicians keep an open mind to the possibility that the present analysis of professional football players may have relevance to college and high school players.”

Asked about the apparent contradiction, Viano said, “I think under that particular scenario the word ‘may’ is appropriate.” . . .

Considering that the bulk of research to date suggests that concussions in high school-aged football players may be even more dangerous than those in slightly older professional ball players--and the problems that professionals are seeing as a result of playing soon after concussions--"may" or "might" are highly inappropriate words for Viano to be using. The Times reporter was right to call him on it.

Sloppy Headlines on Parkinson's Disease

Here's a catchy headline that's guaranteed to get your attention: "Smoking and Caffeine May Protect Against Parkinson's Disease."

It was written by the good folks at the Duke University press office. But it does a disservice to anyone who has Parkinson's disease, or cares for or loves someone with the neuro-degenerative condition.

To make matters worse, it gave journalists permission to use similarly dumb headlines for their copy, like this one from the Miami Herald: "Study: Cigarettes, coffee may help ward off Parkinson's."

How sloppy is the Duke press release on Parkinson's disease? Let me count the ways:

1. Regular readers of The Health Media Watch should pick up right away on the "Mighty May" in this title. Whenever you read the word "may" in a health article (or press release) you should always add the phrase "or may not" to the sentence. In other words, "Smoking and Caffeine May or May Not Protect Against Parkinson's Disease."

2. The risk picture is incomplete. "Individuals with Parkinson's disease were half as likely to report ever smoking and a third as likely to report current smoking compared with unaffected relatives," according to the press release. No clue what the absolute risk is of developing Parkinson's disease in one's lifetime as to compared to, oh let's say, LUNG CANCER.

Instead we get just the following dutiful sentence: "Smoking cigarettes and consuming copious amounts of caffeine carry their own risks and should not be taken up in an attempt to avoid developing Parkinson's disease, cautions study investigator Burton L. Scott, M.D., Ph.D., associate professor of medicine."

For the record, about 1 in 100 (or 1%) of people develop Parkinson's disease at some point in their LIFETIME, according to data from the Centers for Disease Control.

But a 68 year-old man who has smoked two packs per day for 50 years and continues to smoke has a 15% chance of developing lung cancer in just the NEXT TEN YEARS (Bach PB, et al. Journal of the National Cancer Institute, 2003).

3. An association does not prove causation. Maybe the folks with Parkinson's were less likely to have smoked because they have less addictive personalities. In that case, smoking would be a side effect of whatever genetic predisposition made you less likely to develop Parkinson's disease. Or maybe, as Maggie Fox of Reuters pointed out in her article, people who are predisposed to developing Parkinson's disease just don't like coffee as much as their counterparts.

How To Think About Hormones and Dementia

How old a woman is when she takes supplemental hormones may determine whether it helps to protect her against developing dementia later in life, according to a new analysis of data from the Women's Health Initiative that was presented at the American Academy of Neurology annual meeting in Boston.

Readers of this blog will immediately note the "Mighty May" and will mentally rewrite the news as "hormones, depending on when they are taken, may or may not help prevent dementia."

Here's why this research is considered preliminary and not definitive.

The researchers looked at the original Women's Health Initiative (WHI), which conclusively showed a few years ago that years and years of hormone replacement therapy (either estrogen alone or estrogen plus progestin) actually increased the risk of dementia in women 65 and older.

The new analysis was designed to answer the question whether timing matters when starting hormone therapy. But instead of conducting a randomized, controlled clinical trial--which would give a definitive answer but would be costly and unlikely to get many participants because of what has already been shown about long-term hormone therapy--the researchers, led by Victor Henderson of Stanford University in California, looked at the questionnaires the women filled out.

Based on the women's responses, Henderson and his colleagues created a new set of data points that showed which women started hormone therapy early--before menopause or after menopause.

On the basis of those answers, the researchers determined that early hormone therapy was protective, while later therapy--started after age 65--was not.

But the conclusion rests on what the women reported about themselves so it's subject to recall bias.

Also, women who turned to hormone therapy throughout the 1980s and 1990s are known to be healthier overall than those who didn't. In other words they started off healthy, wanted to stay that way and had access to doctors. So even if they accurately remembered whether or not they took hormones, that could simply be a measure of how healthy they were in the first place.

The bottom line: if you're having severe menopausal symptoms and want relief, you may want to consider hormone therapy--but only for one or two years. Taking hormones in the hopes of staving off Alzheimer's or heart disease in the future is still more likely to hurt you than to help you.

On the other hand, if you're worried about dementia, there's compelling evidence that your best bet is to get plenty of exercise and avoid getting hit in the head.

Sources:
1. The Women's Health Initiative
2. Shumaker SA, et al. "Estrogen plus progestin and the incidence of dementia and mild cognitive impairment in postmenopausal women: the Women's Health Initiative Memory Study: a randomized controlled trial," JAMA. 2003 May 28;289(20):2651-62
3. Shumaker SA, et al. "Conjugated equine estrogens and incidence of probable dementia and mild cognitive impairment in postmenopausal women: Women's Health Initiative Memory Study," JAMA. 2004 Jun 23;291(24):2947-58
4. Larson, EB, et al."Exercise is associated with reduced risk for incident dementia among persons 65 years of age and older." Ann Intern Med. 2006 Jan 17;144(2):73-81
5. Guskiewicz KM, et al. "Association between recurrent concussion and late-life cognitive impairment in retired professional football players. Neurosurgery. 2005 Oct;57(4):719-26

Why Chocolate is Not a Health Food--Sigh

I've always loved chocolate--especially dark chocolate. But the recent flurry of stories that chocolate could be some kind of wonder food leaves a bad taste in my mouth. This falls into a category of stories that journalists love to report and consumers love to read: Hey, what you think is bad for you is actually good. (And let's not forget another closely related category: what you think is good for you is actually bad.) This is the kind of story that tells you a lot more about human nature than it does scientific truth.

The latest round of chocoholic wish fulfillment is based on a study by Dr. Norman Hollenberg in the International Journal of Medical Studies (IJMS). In it, Hollenberg and his colleagues assert that the reason why the Kuna Indians of San Blas Island off the coast of Panama seem to suffer from less cancer and heart disease than their counterparts on the mainland is that the Islanders drink five or more cups of cocoa each day.

We're not talking Swiss Miss here. The cocoa is minimally processed from local cocoa plants (and if you've ever tasted real cocoa, you might wonder how they can swallow five cups of the stuff a day--boy, is it bitter!)

But there are plenty of red flags in even the most gleefully credulous press reports of Hollenberg's findings. To start with, we have the "mighty may." Cocoa may--or may not--help prevent cancer and heart disease. Even the authors have this to say about their own study: ". . . there are many risk factors and an observational study cannot provide definitive evidence."

There's also a potential funding bias since the research was supported in part by the Mars company, manufacturer of M&Ms and other fine candies.

Hollenberg is in the radiology department at Brigham and Women's Hospital in Boston. Nothing against radiologists but what do they know about nutrition? Yet, in my admittedly unscientific review of the popular press, I found not a single case of a reporter who had contacted a nutrition researcher for comment.

The further I dug into the original research paper in the IMJS, the more questions I had. For example, the investigators compared Kuna Indians on the island to everyone in Panama--not just to Kuna Indians on the mainland. That's like comparing apples to oranges.

Also, the quality of the original data is in question since the causes of death were derived from death certificates that may have been less precise on the island.

And why did more island residents die of infections than those on the mainland? Could that have been the result of drinking too much cocoa?

Well, you get the picture. I love chocolate. I think flavenoids are some of Nature's most important disease-fighting agents. But I eat chocolate--in moderation--because I love its taste, not because I think it's some kind of health food.

Is Sleeping in Bed Harzardous? Not!

Most people die in bed, the NIH's Dr. Jacques Rossouw said yesterday while the two of us were waiting to participate in a media panel on communicating complicated nutrition science. That doesn't mean that beds are hazardous to your health.

We were talking about how easy it is to draw the wrong conclusion from studies that detect a link or association between two different--and yet objectively truthful--factors or trends.

These so-called observational studies are the least rigorous type of scientific study and yet they often get lumped in with well-controlled, randomized trials in terms of believability.

Observational studies are responsible for more cases of what I call the "Mighty May" than just about anything else.

Still, they can be useful. Observational studies were the first evidence of the very real cause-and-effect relationships between smoking and lung cancer, emphysema and heart disease.

Other times, observational studies lead you down the garden path to the wrong conclusion. They have their place in the scientific enterprise but should be interpreted with caution.

Otherwise, you get headlines that are the equivalent of saying "Sleeping in a bed may be hazardous to your health."