The Great Durian Poll outcome

Many thanks to all who participated. We managed a half decent 66 responses... :).

I must say I was somewhat surprised by the results. As a non-durian lover I was expecting to see a much clearer separation of lovers and haters, with perhaps a more distinct bimodality in the distribution, somewhat like the taster/non-taster distribution. Instead we had a kind of log-normal distribution, like the CYP3A4/5 one.

There are a couple of possible reasons for this. One is that there may be a sampling bias, i.e. non-durian lovers aren't that motivated to participate. Secondly, the category axis is an ordinal scale, so even though I tried to space out the responses as 'equally' as I can imagine them to be, there is no certainty that the categories have equal intervals. It could well be that there is a larger separation at the "So-so only....no big deal" category.

In any case, it was an interesting exercise. As has been shown many times before, the lack of a clear 'bi- or poly-modal' distribution does not necessarily exclude any genetic bases for the interindividual differences.

Regardless of the genetic or lack of genetic basis for the interindividual difference, (and assuming the sample represents all of Singapore) there is an interesting lesson for us here...

Firstly, because of the preponderance of durian lovers in the sample, one can say Singaporeans generally love durians...passionately...though they can mostly live without it. Secondly and perhaps more importantly, is to recognize that despite such an overwhelming support for the spikey fruit, there are regulations that protect the interests of the people represented by right tail of the distribution. You don't allow the fruit on airplanes, in cars, shopping centres and restaurents. It is such a common sense thing to do, so we kinda take it for granted. It is actually a very common phenomenon. In a classroom, for example, the (good) teacher's attention is often focused on the poor students, or the bright spark...and not on the majority of the students who (on average) do not have any problems.

We have the same situation in dealing with therapeutic problems. Most dosage regimens are designed for the average patient (central tendency, remember?), and we know (or should know) that the patients who develop problems are those at the tails of the distribution...either inadequate response, or too much response/toxicity. Our mental focus should really be on helping the patients in the tails of distribution achieve an appropriate therapeutic response. Yet physicians often forget this and assume that the recommended (average) dose will meet the needs of all the patients they treat.

The challenge for us is in helping physicians identify which of the patients reside in the tails. This is where pharmacogenetics come in.

There is a nice review, "Pharmacogenetics - Tailoring Treatment for the Outliers" in the New England Journal of Medicine by Woodcock and Lesko that deals with this specific issue. It also reminds us of what Sir William Osler had shared over a hundred years ago: "If it were not for the great variability among individuals, medicine might as well be a science and not an art." Paradoxically, medicine is now at a stage of development where dealing with this variability has become much more of a science.

Durian lovers vs durian haters

Here's a slight frivolous post inspired by tonight's after dinner conversation.

The durian (Durio zibethinus), reckoned by many as the king of fruits in Asia. Others have less flattering descriptions. It's a fruit that you either love or hate.

Some descriptions of its taste (shamelessly plagiarized from Wikipedia):
Writing in 1856, the British naturalist Alfred Russel Wallace provides a much-quoted description of the flavour of the durian:
“The five cells are silky-white within, and are filled with a mass of firm, cream-coloured pulp, containing about three seeds each. This pulp is the edible part, and its consistence and flavour are indescribable. A rich custard highly flavoured with almonds gives the best general idea of it, but there are occasional wafts of flavour that call to mind cream-cheese, onion-sauce, sherry-wine, and other incongruous dishes. Then there is a rich glutinous smoothness in the pulp which nothing else possesses, but which adds to its delicacy. It is neither acid nor sweet nor juicy; yet it wants neither of these qualities, for it is in itself perfect. It produces no nausea or other bad effect, and the more you eat of it the less you feel inclined to stop. In fact, to eat Durians is a new sensation worth a voyage to the East to experience. ... as producing a food of the most exquisite flavour it is unsurpassed.”

While Wallace cautions that "the smell of the ripe fruit is certainly at first disagreeable", later descriptions by westerners are more graphic. British novelist Anthony Burgess writes that eating durian is "like eating sweet raspberry blancmange in the lavatory." Chef Andrew Zimmern compares the taste to "completely rotten, mushy onions." Anthony Bourdain, while a lover of durian, relates his encounter with the fruit as thus: "Its taste can only be described as...indescribable, something you will either love or despise. ...Your breath will smell as if you'd been French-kissing your dead grandmother." Travel and food writer Richard Sterling says:

“... its odor is best described as pig-shit, turpentine and onions, garnished with a gym sock. It can be smelled from yards away. Despite its great local popularity, the raw fruit is forbidden from some establishments such as hotels, subways and airports, including public transportation in Southeast Asia.

Other comparisons have been made with the civet, sewage, stale vomit, skunk spray and used surgical swabs.

There are clear indications that this is a pharmacogenetic differentiation of durian lovers from haters, though I do not know of any study to this effect.

Go ahead and take the Great Durian Poll!!