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You’ve probably seen your fair share of stories about how a certain substance in a certain food will keep you from getting cancer or some other ailment. In fact, they’ve become almost impossible to miss... popping up every week on TV, in newspapers, on the web and... yeah, we’ve done a few on this show. But as we binge on one story after another, maybe we should stop for a second and ask: are we really learning anything? The Health Show’s Greg Dahlmann took a moment to follow up on one of these stories.. and he found that when consuming food news... it pays to take it with a grain of salt.
(originally aired February 03, 2005)
8:02 | listen: RealAudio · mp3
As headlines go, this was a great one... it read... “Study: an apple a day really does keep doctor away.” What a score! It’s snappy, funny, grabs your attention... and -- as it turns out -- a complete misrepresentation of what the study was actually about.
A research team at Cornell University led by Dr. Chang Lee had been looking into the properties of a chemical called quercetin. It’s found in a number of different fruits and vegetables... especially in apples. So the researchers extracted quercetin from apples, soaked rat brain cells in the compound... and then exposed the cells to hydrogen peroxide in order to see how well quercetin protected the cells. And they found it did a pretty good job compared to that more famous antioxidant vitamin C. That’s of some interest because one of the current theories regarding Alzheimer’s is that it’s associated with oxidation in the brain.
So, the Cornell scientists might be onto something good here, right? Well, Dr. Lee says maybe, and maybe not.
{CL: not saying it prevents} :24
"This is a first, an initial step that we found some beneficial compound in apples and that gave us a positive effect, therefor I recommend eating more fruits and vegetables that comes along with other health benefits. I’m not saying right at this moment that eating apple prevents Alzheimer’s or cancer, no."
Here's were things started to get a bit wobbly, though. When the Cornell team's findings ended up in the Journal of Food Science... the conclusions section included this quote:
"Because apple is one of the rich sources of antioxidant among fruits and has many important bioactive compounds, daily consumption of an apple may provide the beneficial effects that may reduce a risk of chronic diseases including Alzheimer’s disease."
And then Dr. Lee was quoted saying this in a Cornell press release:
"Indeed, I have a reason to say an apple a day keeps the doctor away."
And headline writers gobbled it up. From a press release for the US Apple Association: "Cornell Scientists Report Apple Brain Health Benefits". "Learn to love those Granny Smiths!" blared a headline from a South African news outlet. From India: "An apple a day keeps Alzheimer’s at bay!" And on MSNBC-dot-com: "An apple a day keeps doctor away"
{JG: a far cry} :19
"I think that going from a study in which a finding that a particular compound – and particularly if you eat the skin of the apples -- is associated with some changes in rat brains is a far cry from a recommendation of an apple a day."
Jean Goldberg is a professor of nutrition at the Friedman School of Nutrition at Tufts University. One of her main areas of research is how nutrition science is translated from experts to the general public. She says items like this apple story pop up a lot these days... especially since research institutions and growers' groups have stepped up their P-R efforts. The problem – as Jean Goldberg sees it – is that most of these studies aren’t really ready for public consumption... and the resulting news coverage usually ends up confusing people.
{JG: people confused} :22
"I’ve been in the local green grocer where I shop and listened as women turn to each other and say, 'You know, I don't know what to do. Yesterday they told me it was blueberries, you know, today it's apples, what are they going to tell me tomorrow, that we should be eating handfuls of raw cranberries.' You know, it does really get a little bit loony."
But what's the big deal here? If research shows a compound in apples keeps cells safe in a test tube... what's wrong with telling people to load up on macs and galas? Well, the problem is that this kind of research is only one piece of the puzzle. Dr. Jose Luchsinger is an assistant professor of medicine at Columbia University and the school's Taub Institute for Research on Alzheimer's Disease and the Aging Brain.
{JL: study shows one piece} :27
"When the authors say that it may be helpful in neurodegenerative disorders, that's a big leap. And the key word is 'may.' And I'm not saying that's not true. It's just that that's a small piece of evidence that needs to be taken in the context of the larger body of medical evidence."
And that larger set of research is kind of murky. There have been a lot studies looking into the effects of antioxidants on the brain... but Dr. Luchsinger says most of them are inconclusive. And the ones that have shown promise in the lab... or from observing populations of people... often don't pan out in human trials.
{JL: biology complicated} :35
"Conditions in the lab are usually very simple conditions where you control all the environment in which you do the experiment so that you look at just one thing. But human beings are very complicated, they're bodies are complicated. They're exposed to the environment, what they eat, the air, etc. So, you know, biological processes are much more complicated in real life and in populations than they are in the laboratory."
Jose Luchsinger says that complexity sometimes leads to unexpected outcomes. He uses hormone replacement therapy as an example. In the initial studies, it looked like hormone therapy would provide a host of protective effects to women as they aged. But when it was carefully tested on a large number of people... the results were actually just the opposite.
{JL: HRT restated} :14
"A lot of researchers were not surprised at this because this is just sort of the nature of science, this is something that can happen. So, you can't put the cart ahead of the horses. You have to wait until all the evidence is in."
The thing is... we’re really bad at that in the media. We love to jump to the end. It makes a so much better sounding story than: "Scientists tested a chemical found in apples on rat brains and there’s some chance it could provide useful information about preventing dementia, but the fact is we're really don't know for certain and we won't know until much more research, at considerable cost, has been conducted... probably many, many years in the future." It just doesn't have the same zing, does it?
But we all play a part in this process of mixing things up... the journalists, the P-R people... even the scientists. Chang Lee – the professor from Cornell – was very upfront about the fact that his team's findings were preliminary and did not indicate that eating apples would keep people from getting Alzheimer’s. But, at the same time... he had no problem with using the apple-a-day line in the press release.
{CL: apple a day} :45
"I can use that terminology at this stage because apple is good food to maintain good health, especially today's American health. So I just follow that, and I can use that. (GD: So, you're OK with the media saying that's what your research says?) Because when I look at all nutritional quality, apple has not single negative aspect. So, if you eat more apples, especially compared to high fat, high cholesterol food, I think the apple is good therefor I can recommend it."
And Professor Lee is right... no one's saying apples are bad for you. And you could certainly do much worse. But the headlines that proclaim "An apple a day keeps the doctor away" are simply misleading. We don't know if that's really true or not. And the next story like this to come along might not prompt the public to take up such a healthy course of action. So like with many other things we see on the news... it pays to be skeptical. Or as Tuft's Jeanne Goldberg puts it...
{JG: if it sounds too good} :03
"If it sounds too good to be true, it probably is."
For The Health Show... I'm Greg Dahlmann.
a journalist
pieces from various public radio programs
Albany, NY
now and then
it's complicated
why not
gdahlmann (at) hotmail dot com
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