To start off, I recognize I’m painting with a broad brush with the title. But I’m going to use a high-profile journalist on a high-profile news show to illustrate that you just can’t take science reporting at face value from news outlets. There are some people who don’t suck at reporting science, like Carl Zimmer or Jennifer Ouellette, but the ones that are really good at it seem to call themselves science writers more often than journalists. I’m not talking about them here. I’m talking about the people who specialize in reporting the news, not in the science.
Earlier this week, Lesley Stahl of the CBS news show 60 Minutes reported on a University of California, Irvine, study called “The 90+ Study” that looked at a cohort of 14,000 residents of a retirement community who filled out an extensive health questionnaire in 1981. Those people are now over 90 years old and they’ve tracked down as many as they can to learn about longevity and health in the “oldest old.”
All that is fascinating, and they’ve found out some really interesting stuff, particularly about dementia. But I want to focus on two items that stuck out at me between what the interviewed researcher, Claudia Kawas, said and the terminology used in the news story. The first is about alcohol, the second about caffeine.
With alcohol, the study published in 2007 pointed out that those who drank alcohol in moderation lived longer than those who did not, but:
We found no difference in the effects of wine, beer or hard liquor on mortality. Whereas several studies have not observed any differences between wine, beer and spirits in their association to all-cause mortality, others have shown more benefit for wine, and/or beer, and/or spirits. In many cases, the strongest inverse relation has been observed for the beverage type most often consumed in the population under study.
In other words, type didn’t matter in their study, but other studies where there’s a most common type of alcohol, in which case that might show up as being “better” for longevity. But here is where the reporting of the study becomes slightly skewed. Not misleading exactly, but a viewer not paying full attention might go away with a different impression than what the science found.
In the report, Leslie Stahl did indeed say, “And any kind of alcohol seemed to do the trick.” This was followed by Kawas being quoted to say, “A lot of people like to say it’s only red wine. In our hands it didn’t seem to matter.” Replying, Stahl said, “Martinis just as good.” And that was the only time an alcoholic beverage other than wine was mentioned. The word “wine” was used 5 times in the story. “Beer” was not mentioned at all, nor was any representative of hard liquor other than the reference to a martini. So although they actually said the type of alcohol didn’t matter, the story only really talked about wine. This is what might give the casual listener an inaccurate sense of the study’s findings.
(An interesting, but unrelated wrinkle in the research for those of us who don’t drink alcohol: although alcohol seemed to have a protective effect, so does grape juice. This raises two questions: if alcohol is what makes the difference, why does grape juice work? And if it’s something from the grapes, why does beer and spirits come out even with wine? My guess is what I say in most of my tea classes: It’s more complicated than that.)
Now, to bring it back to tea: caffeine.
For this one we refer to a study the research team published in 2008 looking at, among other things, caffeine consumption. The 60 Minutes story says, “And there’s good news for coffee drinkers. Caffeine intake equivalent to 1-3 cups of coffee a day was better than more, or none.” Okay, so they don’t mention tea because coffee is more common. I’ll give them that. The study itself said that 90% of the people drank coffee and only 50% drank tea. But then they say that it’s caffeine, and it’s the equivalent to 1-3 cups of coffee a day that makes a difference.
But it isn’t.
Looking at the published study, they found that tea drinking only made a small amount of difference and mostly in those with cardiovascular disease. On the other hand, they found that people who drank decaffeinated coffee had reduced risk. They talk about lots of complexities in the analysis and problems with measuring and so forthâ€”like that answers about “tea” might have included decaffeinated, and I might add herbal, teaâ€”but what comes through clearly is that it’s really coffee that makes the difference. So the most scientific-sounding bit about this issue in the news story turns out to be the least accurate. It’s the common reference to coffee as a caffeine source that’s really the bit that had the most evidence behind it. But the study did specify that “Individuals drinking 100â€“399 mg/day had the lowest risk.” Of course, if you have talked with me about caffeine, you’ll know it’s very difficult to know how much caffeine you’re getting in a cup of tea.
(By the way, for those of you that are still on the “tea is great for your health” bandwagon, they not only found “Neither milk nor tea had a significant effect on mortality after multivariable adjustment,” but they also found that the antioxidant activity of vitamin E had no significant impact on reduced risk. So if you’re drinking tea because of the antioxidants, the fact that you’re consuming more may not mean you’ll get any benefit).
I wind up, then, coming back to the two assertions in the title (with no disrespect intended for Leslie Stahl or 60 Minutes, despite using them as an example): News journalists suck at scienceâ€”or at least don’t have the time or an audience who cares enough to actually get accurate with their description of findings. And tea won’t help you live longerâ€”unless maybe you have cardiovascular disease, and it could be that tea’s antioxidants don’t do much for you.
But in the end it boils down to this: Do your research. Don’t believe what the news or salespeople tell you about science. Instead, do a little research yourself because they probably didn’t quite explain it correctly.
Transcript and video of the news story, which really is rather interesting despite the oversimplification of the findings: Living to 90 and Beyond