IRA FLATOW, host:
This is Talk of the Nation: Science Friday. I'm Ira Flatow. A little bit later in the hour, we'll talk about several steps you can take to save energy. But first, some hopeful news for those of us who stumble into the kitchen groping for that first cup of coffee, bleary-eyed, stressed-out from a bad night's sleep. New research suggests that just a whiff of roasted coffee can alleviate some of the stress caused by missing sleep, at least, for rats.
A team of researchers found that in laboratory studies, just the scent of roasted coffee beans altered the activity of over a dozen genes in the brains of rodents who were deprived of sleep. At first, when the researchers deprived the rats of sleep, the activity of several important stress-relieving genes decreased, but the activity of those genes rose again to above-average levels when the sleepless rats smelled the roasted coffee. So, should we start smelling our morning coffee instead of drinking it? Do we know enough about people to say so?
Joining me now to talk about the stress-relieving aroma of coffee, research out in the Journal of Agricultural and Food Chemistry, he's my guest, Yoshinori Masuo. He is a neuroscientist and head of the mental stress team at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan. That's northeast of Tokyo. He's joining us on the phone, in the middle of the morning, late at night from Japan. Welcome to the program, Dr. Masuo.
Dr. YOSHINORI MASUO (Neuroscientist, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan): Hello, good afternoon.
FLATOW: Thank you. Did the rats in your experiment smell the coffee before the experiment started?
Dr. MASUO: I'm sorry, I can't hear you.
FLATOW: Let me ask it again.
Dr. MASUO: Yes?
FLATOW: Do the rats like the coffee smell?
Dr. MASUO: Yes, the first author in our paper, Dr. Seo told me that the rats prefer a certain kind of coffee, Colombian. We don't...
FLATOW: Oh, they...
Dr. MASUO: Yes?
FLATOW: They like Colombian coffee.
Dr. MASUO: Yes, but we don't know the difference among Colombian and others scientifically. But I met some specialists of coffee and they said, at a level of aroma, we prefer Colombian.
FLATOW: Why did you do this experiment with aroma rather than tasting the coffee?
Dr. MASUO: There are many previous papers showing the effects of coffee drinking. So, the effects of caffeine, but the effects of caffeine is not so clear yet, and we know that the aroma can attenuate at stress levels. So, we decided to measure molecular levels and molecular changes in the brain.
FLATOW: And so, you found that there was - that the aroma of the coffee reduced stress?
Dr. MASUO: Yes.
FLATOW: Do we - do - would - do we - would we think that in people, this might work the same way? Is it possible to test this out in people?
Dr. MASUO: Yes, it's possible, of course.
FLATOW: Mm-hm. Would you be doing that? Or do you leave that to someone else?
Dr. MASUO: Actually, I don't care because the...
(Soundbite of laughter)
Dr. MASUO: Because the - our goal is to establish the stress-measurement system in human blood. So, we just tested the effects of coffee aroma on the stress.
FLATOW: Would you then think that when we drink a cup of coffee, perhaps some of the satisfaction we get from drinking the coffee comes from smelling the coffee, too, perhaps?
Dr. MASUO. Yes, sure. Because that - when you drink a coffee, you cannot avoid the smell - smelling a coffee. And we just examined the effects of coffee aroma and we observed the automations(ph) in gene expression, in protein expression.
FLATOW: Mm-hm. What kinds of effects - you say gene expression and protein expression, what effects do they have on the brain?
Dr. MASUO: For example, we observed observations in several factors, but I'd like to talk about two typical examples. One is nerve-growth factor. This factor pro - promotes resistance to stress and enhances cell survival. So, it protects and rescues the brain from injury. Another one is glucocorticoid. This is involved in anxiety and endocrine controls, stress degrees, gene expressione of receptors for these two factors and coffee aroma made them recover. These changes may be associated with anti-stress effects of coffee aroma.
FLATOW: So, if you're staying - trying to stay up all night to study, should you drink the cup of coffee or smell it?
Dr. MASUO: Oh, that's an excellent question. Drinking coffee includes aroma, taste, caffeine and many factors. Among these, we just studied the aroma. And we don't mean that the smelling is better than drinking. In some online journals, they misinterpreted our work, saying stop drinking and smell coffee. But of course, you can enjoy drinking because you can smell the coffee at the same time, and the smell will rescue your brain.
FLATOW: You know, here in America, we don't think about the Japanese as coffee drinkers. We think of you as tea drinkers.
Dr. MASUO: Oh. That's actually - we drink a lot of coffee. In view of the amount of coffee, the first imported country is the United States, of course, and the second is Germany, and Japan is the third. We also need coffee to be awake.
(Soundbite of laughter)
FLATOW: Well, what about tea? Do you suspect there might be some aroma of tea that might have a similar effect?
Dr. MASUO: I think tea has similar effects, although we don't study it yet. Aroma can help the stressed brain. From the tea? I think so. There are some publications on aroma, for example, the aroma of lemon, the rose, and lavender. Physiological studies suggest that such good smells make animals feel relaxed. So, it may be possible to show evidence of molecular changes in the brain. Now, we have many things to do.
FLATOW: So, you can - you might be able to find aromas of other things that make us relax, like aroma therapy.
Dr. MASUO: Yes, sure.
FLATOW: So, smelling coffee is like aroma therapy then.
Dr. MASUO: Yes, I think so.
FLATOW: Yeah, that's terrific. Well, thank you very much for - I know it's in the middle of the morning, late at night for you. Dr. Masuo, thank you very, very much for staying up to talk with us.
Dr. MASUO: OK, you are welcome.
FLATOW: You're very welcome yourself. Dr. Yoshinori Masuo is a neuroscientist and head of the mental stress team at the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan.
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