Tuesday, June 30, 2009

What's Your Poison?


The classic recipe for brewing tea, in the Asian traditions of the last several hundred years at least, has been breathtakingly simple: tea leaves and hot water. Indeed the Japanese name for their traditional tea ceremony, cha no yu (茶の湯), means, literally, 'hot water for tea.' And yet this is not universally the case -- not even in Pacific Asia -- nor was it always this simple: the history of tea has often included a dialogue about what to add to it, how, when, and why. Or, in some cases, why not: Lu Yu's recommendation, in the Cha Jing -- that you refrain from adding onions to your tea -- makes it clear that one of the fashions in Tang Dynasty China was to do just that. To this day, Tibetan tea drinkers famously add (rancid) yak butter and salt to their tea (po cha, 'butter tea,' or cha süma, 'churned tea') -- the tea leaves in this case being typically pu'er or some other post-fermented hei cha. In this way, cha süma becomes a significant source of calories and other nutrients.

Today worldwide, the two things most commonly added to tea are surely milk (or cream, though purists in the West object to this), and some sort of sweetener. The human organism seems pretty tenaciously hooked on consuming sugar: studies show that even newborn babies, just a few hours old, will drink more enthusiastically from a bottle of sugar-water than from a bottle of plain water. Doubtless it all has to do with the preservation of the species -- some hard-wired genetic instructions about the importance of stocking up on readily-available carbohydrates.

It's a pretty fair guess that most inveterate drinkers of oolongs, pu'ers, and greens rarely sweeten their tea. But it's equally certain that many of those who drink 'black' teas -- Ceylons, Assams, Chinese hong cha, and other fully-oxidized teas -- add some sort of sweetener to it. This is true in Asia as well as the West: Hong-Kong style 'milk tea', surely a legacy of British colonial rule, is nonetheless made to be drunk with sugar.

But there's always something, isn't there. In this case, it's that we have not yet developed the bodies that allow us to live entirely happily with refined sugar. One of the most assured results of modern science is that too much sugar has a baleful effect on our health -- causing dental caries, obesity, various digestive woes, and even diabetes. This knowledge hasn't stopped 20th- and 21st-century manufacturers from adding massive amounts of sugar to our food. (If you think 'massive' is hyperbolic, have a look at the website sugarstacks.com and then rethink the matter.)

Part of the problem, it seems, is the chemical form the sugar takes, and the way our bodies cope (or fail to cope) with it. A few names, definitions, and links for further reading:

glucose -- the simple C6H12O6 found in e.g. human blood
dextrose -- a stereoisomer of glucose
fructose ('fruit sugar')
sucrose ('table sugar') -- a disaccharide of glucose + fructose

Mono- and di-saccharides such as glucose (dextrose), fructose, and sucrose are so simple that they are metabolized very quickly; our bodies often cannot produce enough insulin to process them as fast as we ingest them. As a result, they tend to be metabolized to fat, and stored as adipose tissue -- again, sometimes overtaxing the pancreas in the process.

The deleterious effects of sugars on teeth are not only well known, but also clearly visible in the mouths of those who suffer from them. There are those in the scientific community who point to refined sugar as one of the possible culprits in producing Irritable Bowel Syndrome (for just a small sample of information, at lower and higher levels of technicality, click on this link and this link.

So: what to do?

Since the 1950s at least, honey has been touted as a 'healthy' alternative to table sugar. The basis for this allegation is, presumably, the presence -- in unfiltered honey -- of pollens, vitamins, and minerals; but the fact is that these occur in such small amounts that it is not realistic to think of honey as a significant source of such nutrients. To take one example: five tablespoons of honey contain only 1% of the US adult RDA of vitamin C.

'Hot tea with honey and lemon' has long been a comfort beverage and folk remedy in the West, for colds and sore throats. But chemically speaking, the sugar in honey is not drastically different from granulated sugar (fructose + glucose) -- and probably not a much more 'healthy' choice. In fact, its extreme viscosity might conceivably make it even more conducive to dental caries than table sugar.

Similarly disappointing news awaits those who had looked to agave syrup (or 'agave nectar' as it is fetchingly known in the industry). Diabetics and others had early hailed this as a natural low-glycemic-index food -- a sweetening agent, in other words, that [a] was refined from an item found in nature, [b] could be produced organically, and [c] was not a threat to blood-sugar levels. Alas, agave syrup is principally fructose, which appears to put its own set of stresses upon the body. Ironically, some say that it is even more dangerous for diabetics and hypoglycemics than refined white sugar.

So: what to do?

Many, discouraged by the health issues associated with (and the caloric content of) real sugars, turn to the option of artificial sweeteners. These are numerous and diverse, and their degree of success in mimicking the sweetening effect of actual sugar seems to vary with the individual palate ...

[[This is Part 1 of a two-part essay. To read Part 2, click here.]]

For further reading meanwhile (thanks to Suki for these links!):

Glossary of Sugar and Syrup Types

More on Agave Syrup

And Still More on Agave Syrup


MarshalN said...
This comment has been removed by the author.
corax said...

marshaln, that's fascinating. two questions [to start]:
[1] did you learn to do that in asia? or somewhere else? and
[2] two packs to how many ounces of brewed tea?
i seem to recall reading that some tibetans add sugar [or sweetener of some sort] to their yak-butter tea, too. i wonder if that would be in addition to, or instead of, salt?

Paleo Chef said...

your title is probably truer than you realize.

i can't remember if we've talked about this research, but humans aren't the only mammals predisposed to appreciate sugar; recent research suggests that when given the choice, rats will choose sugar over [even larger doses of] cocaine.

moreover, when deprived of sugar, rats' brains evinced the same symptoms seen in cocaine or heroin withdrawal (including *drinking more alcohol*!).

obviously, there's a fair amount out there suggesting that william dufty was on the right track. (and this guy might be my new hero.)

my own struggle is no longer the caloric sweeteners, but the artificial stuff (yes, even stevia). this may be jumping the gun on part ii of your posting, but in short, i really believe them not to be good, but instead the lesser of evils. there's some anecdotal evidence (on the paleo and diabetes support forums) suggesting that for at least some individuals, AS can cause an insulin response (if not also a blood glucose response!); the mechanism looks like it might be pavlovian (i.e. 'sweet taste' linked to 'rush of carbs into the system'); even without a rise in blood sugar, humans (and other animals) are known to secrete what is called "cephalic phase insulin" in response to just looking at (or even *thinking about*) food.

the other piece of anecdotal evidence that many dieters (and non-dieters) know to be true is that sugar (or AS) can be a "trigger" food. sweet taste, for many, is very moreish - once you've had a taste, you want another one, and another, and the normal hunger/satiety cues that are easy to pay attention to when eating fat and protein are either turned off or at least easier to ignore.

so - longwinded answer short - good on the cultures who don't sweeten their tea :)

MarshalN said...

Sorry Corax -- my first comment was entirely in jest, repeating what a friend from Egypt has told me about their tea drinking customs -- two cubes of sugar in the tea, and then they will politely ask their guest "how much sugar would you like in your tea?". Granted, their tea is very concentrated, but that's a lot of sugar.

I eschew all sugar. In fact, I avoid eating sweets when drinking tea. It affects my tastebuds. The only exception is when I go for English style afternoon tea, then all rules are suspended and I'll eat as many cream/jam covered scones as I can get my hands on.