Azura Cabin Update!

As you may be aware a large portion of our office went down to Southampton on Friday, and had a chance to be some of the first people to spend the night onboard P&O's new ship Azura. By the sound of the things, on the whole this visit went very well, the ship sounds fantastic, the food sounded delicious, the facilities great and overall a memorable experience. Although I was not actually able to make it to the visit, I have picked up quite a few little changes just in your cabin, which may have a big effect for past P&O guests. First of all they have changed all of their toiletry products from Elemis, To the White Company products. For those of you who have not heard of the white company, they are a high end home care accessories company, that offer toiletries in the same league as L'Octaine and Morton Brown, and early feedback from the guys in the office suggests they are as good as any other out there..........
The hairdryers onboard in the cabins are now all Steiner Beauty protects, which I am told which is salon quality. It is also the first time in 15 years that P&O have used Steiner, but they have gone back with a bang. The contemporary Glass kettles, and glass mugs with metal frames that were so unpopular on the Ventura, have gone, and in are plain white kettles with plain white mugs. To summarise, I think P&O have tried to fix all of the "clever, contemporary" mod cons to the cabins that they got so wrong on the Ventura, and replaced them with the same straight forward idea's that P&O cruisers loved in the first place. You know what they say, if it isn’t broke, don’t fix it!

Real vs Placebo Coffee

Coffee contains caffeine, and as everyone knows, caffeine is a stimulant. We all know how a good cup of coffee wakes you up, makes you more alert, and helps you concentrate - thanks to caffeine.


Or does it? Are the benefits of coffee really due to the caffeine, or are there placebo effects at work? Numerous experiments have tried to answer this question, but a paper published today goes into more detail than most. (It caught my eye just as I was taking my first sip this morning, so I had to blog about it.)

The authors took 60 coffee-loving volunteers and gave them either placebo decaffeinated coffee, or coffee containing 280 mg caffeine. That's quite a lot, roughly equivalent to three normal cups. 30 minutes later, they attempted a difficult button-pressing task requiring concentration and sustained effort, plus a task involving mashing buttons as fast as possible for a minute.

The catch was that the experimenters lied to the volunteers. Everyone was told that they were getting real coffee. Half of them were told that the coffee would enhance their performance on the tasks, while the other half were told it would impair it. If the placebo effect was at work, these misleading instructions should have affected how the volunteers felt and acted.

Several interesting things happened. First, the caffeine enhanced performance on the cognitive tasks - it wasn't just a placebo effect. Bear in mind, though, that these people were all regular coffee drinkers who hadn't drunk any caffeine that day. The benefit could have been a reversal of caffeine withdrawl symptoms.

Second, there was a small effect of expectancy on task performance in the placebo group - but it worked in reverse. People who were told that the coffee would make them do worse actually did better than those who expected the coffee to help them. Presumably, this is because they put in extra effort to try to overcome the supposedly negative effects. This paradoxical placebo response reminds us that there's more to "the placebo effect" than meets the eye.

Finally, no-one who got the decaf noticed that it didn't actually contain caffeine, and the volunteer's ratings of their alertness and mood didn't differ between the caffeine and placebo groups. So, this suggests that if you were to secretly replace someone's favorite blend with decaf, they wouldn't notice - although their performance would nevertheless decline. Bear that in mind when considering pranks to play on colleagues or flatmates.

It looks like science has just confirmed another piece of The Wisdom of Seinfeld:

Elaine: Jerry likes Morning Thunder.
George: Jerry drinks Morning Thunder? Morning Thunder has caffeine in it. Jerry doesn't drink caffeine.
Elaine: Jerry doesn't know Morning Thunder has caffeine in it.
George: You don't tell him?
Elaine: No. And you should see him. Man, he gets all hyper, he doesn't even know why! He loves it. He walks around going, "God, I feel great!"
- Seinfeld, "The Dog"

[BPSDB]

Harrell PT, & Juliano LM (2009). Caffeine expectancies influence the subjective and behavioral effects of caffeine. Psychopharmacology PMID: 19760283

Of Carts and Horses

Last week, I wrote about a paper finding that the mosquito repellent chemical, DEET, inhibits an important enzyme, cholinesterase. If DEET were toxic to humans, this finding might explain why.
But it isn't - tens of millions of people use DEET safely every year, and there's no reason to think that it is dangerous unless it's used completely inappropriately. That didn't stop this laboratory finding being widely reported as a cause for concern about the safety of DEET.

This is putting the cart before the horse. If you know that something happens, then it's appropriate to search for an explanation for it. If you have a phenemonon, then there must be a mechanism by which it occurs.

But this doesn't work in reverse: just because you have a plausible mechanism by which something could happen, doesn't mean that it does in fact happen. This is because there are always other mechanisms at work which you may not know about. And the effect of your mechanism may be trivial by comparison.

Caffeine can damage DNA under some conditions. Other things which damage DNA, like radiation, can cause cancer. But the clinical evidence is that, if anything, drinking coffee may protect against some kinds of cancer (previous post). There's a plausible mechanism by which coffee could cause cancer, but it doesn't.

Medicine has learned the hard way that while understanding mechanisms is important, it's no substitute for clinical trials. The whole philosophy of evidence-based medicine is that treatments should only be used when there is clinical evidence that they do in fact work.

Unfortunately, in other fields, the horse routinely finds itself behind the cart. An awful lot - perhaps most - of political debate consists of saying that if you do X, Y will happen, through some mechanism. If you legalize heroin, people will take more of it, because it'll be more available and cheaper. If you privatize public services, they'll improve, because competition will ensure that only the most efficient services survive. If you topple this dictator, the country will become a peaceful democracy, because people like peace and democracy. And so on.

These kinds of arguments sound good. And they invite opponents to respond in kind: actually, legalizing heroin is a good idea, because it will make taking it much safer by eliminating impurities and infections... And so the debate becomes a case of fantasizing about things that might happen, with the winner being the person whose fantasy sounds best.

If you want to know what will happen when you implement some policy, the only way of knowing is to look at other countries or other places which have already done it. If no-one else has ever done it, you are making a leap into the unknown. This is not necessarily a bad thing - there's a first time for everything. But it means that "We don't know" should be heard much more often in politics.

Will Coffee Crack your Chromosomes?

Bloggers were amused by the Daily Mail's latest crap science article - a scary cancer story about research that hadn't even been done yet. The article is about a study to be conducted by some University of Leicester scientists, which will investigate whether coffee intake by pregnant women is correlated with DNA changes in babies, similar to those seen in leukemia. In other words: coffee-drinking might be associated with some molecular changes which might point to a risk of leukemia. We should ban the stuff, clearly.

What did scare me though was this line:

Previous research has shown that caffeine damages DNA, cutting cells’ ability to fight off cancer triggers such as radiation.

Hold on, caffeine is genotoxic? That would be pretty worrying. It wouldn't mean that coffee causes cancer, but it would make it highly plausible. But does caffeine in fact damage DNA? That might sound like a simple question to answer. Sadly not. It turns out that caffeine is one of the most researched chemicals in all of genotoxicology, and after over 1000 studies there's no consensus on what, if anything, it does to DNA. The story is remarkably complex and has all the good elements of a scientific intrigue. This review by Steven D'Ambrosio , for example, convincingly argues that:

A number of [genotoxic] effects have been observed [in the lab]. However, they usually appear after very high doses (> 1 mM) of caffeine in combination with genotoxins, and are usually specific to certain cell types and/or cellular parameters. Humans, on the other hand, consume much less caffeine in the diet...thus, it is difficult to implicate caffeine, even at the highest levels of dietary consumption, as a genotoxin to humans.

That's a relief. But right at the end we find that "This work was supported by the National Coffee Association"! If the author was in the pocket of Big Java, how can we trust him? Was he being bribed, perhaps with sacks of top-grade Columbian beans...? There's good evidence that high concentrations of caffeine can enhance the DNA damage produced by genotoxic agents such as radiation. But most of these experiments used caffeine concentrations hundreds of times higher than most coffee-drinkers are likely to experience. And contrary to the Mail's claim, this doesn't mean that coffee damages DNA - it probably works by deregulating the cell replication cycle to prevent DNA repair, which means that in theory, caffeine could even make cancer cells more vulnerable to chemotherapy (but again, only at extreme doses.) There's little epidemiological evidence of any association between coffee drinking and cancer; what evidence there is seems to suggest that coffee might even protect against some cancers...

Still, one comforting lesson from all this is that it's not just neuroscience in which seemingly simple questions (like is there are an area of the brain for recognizing faces?) can turn out to be much more complicated than one might hope...

S Dambrosio (1994). Evaluation of the Genotoxicity Data on Caffeine Regulatory Toxicology and Pharmacology, 19 (3), 243-281 DOI: 10.1006/rtph.1994.1023