Now I know I'm going to sound like one of those elitist intellectuals that I despise when I say this, but the science you read about in most popular magazines and newspapers ain't science, baby. The very worst pop science ideas are ones that try to scare you into doing or not doing something based on flimsy evidence.
Here's an example that I just made up, but I wouldn't be surprised to see it in this month's issue of Ladies's Home Journal or Reader's Digest. The headline of the article would blare something like "Twinkies Can Cause an Early Death!!!!!!" The article will open with an interview with a thoughtful young mother who says, "I never thought that something so tasty and delightful to my adorable children could cause so much damage to their fragile little bodies."
Then the article will site a study in some obscure medical journal where out a group of 50 people, those that ate a twinkie every day were 20% more likely to die of a heart attack before the age of 50 than those that did not eat a twinkie every day. Of course, some people might conclude that twinkies are harmful to your health and will cause you an early death.
However, this study would show, like most of the studies in JAMA, a correlation, not a causation. There may be a correlation between eating a twinkie every day and dying of a heart attack before age 50, but there is no evidence that twinkies actually cause heart disease. First of all, I would look at the size and composition of the sample group. If the sample size is small I wouldn't trust any conclusions the researchers came up with. Also, the sample group should accurately represent to whom the study would apply. Does the sample group contain a representative number of males, females, racial types, age groups, body types etc.? In the imaginary twinkie study for instance, I could have stacked the cards by selecting all the young, healthy, athletic people for the control group(non-twinkie-eating), and all the overweight, old people with bad hearts for the twinkie-eating group.
Also, how can one control for just the twinkie eating behavior? I think it would be nearly impossible to select a sample group that had everything in common except for the twinkie-eating behavior. The twinkie-eaters are more likely to engage in other unhealthy behaviors like not exercising, eating 3 bags of potato chips daily, and super-sizing their McDonald's combos while the non-twinkie-eaters are more likely to eat tofu and practice yoga. But that shouldn't affect my decision to have one lousy twinkie today.
And of course, there's always the possibility that the researchers or the magazine editors tweaked the statistical results to favor their position: that twinkies are bad for you. So then the food police decide cite the twinkie study and lobby for higher taxation or outright banning of twinkies and other "dangerous" foods.
Now I don't have a problem with clinical correlational studies. They are useful for showing trends in conjunction with other studies, such as combining a more representative twinkie study with studies on many different types of foods to show that in general a healthy diet is better for you. But I think that many lobbying groups and media sources use studies like my phony one to promote their own agendas.
Here's some examples:
Study shows 9/11 cause heart attacks.
Center for Science in the Public Interest Issues list of "Better and Worse" Snacks for kids
California to Sue EPA over Global Warming
All three of these article were written by Steven Milloy who runs a website called JunkScience.com. He does a great job of exposing the flaws in many of these studies and the motivations behind the groups that use these flawed studied for their pet causes.
Another webpage that might be of interest to those of you who want to be able to eat your dingdongs and twinkies in peace is The Center for Consumer Freedom. Now I'm going to get a Snickers bar. Just try and stop me, you food Nazis!