Sugar sneaks in large doses
I've hammered on about fructose and sucrose already, but here's some context, a glass of OJ. Good for you, so they say ....
There's been a stir up amongst dieticians and endocrinologists etc of late, concerning fructose and sugar and the whole food pyramid (see Good Calories, Bad Calories by Gary Taubes in particular). In a previous blog entry I've quoted Prof Lustig where he talks about the evils of fructose. There's a number of rebuttals popping up about his talk, mostly the rebuttals talk about context - which is to say that in appropriate doses fructose is ok, and of benefit. Sure, it is. Fructose has a benefit, in the liver (which is the only place it's metabolised) it replenishes liver glycogen stores, which is very handy if you're glycogen depleted, eg after a hard training session. Once those supplies are replenished, excess fructose is then released into the blood stream or stored in the liver as triglicerides (fat). I'm going to write more later on the subject of choosing your experts (or, who do you believe?), but that's a topic for another blog entry ....
So, let's look at context for a few minutes and try and clear away a tiny bit of the hand waving.
Let's take a real-world example. A 250ml glass of orange juice. I went to the local shop this morning and got a bottle of orange juice. No added sugar. Ok, that's the best case scenario. Let's be conservative and assume that it's drunk by the metric cup, which is 250ml (no-one drinks 250ml cups, but again, being conservative ...).
Orange juice as provided by The Original Juice Co in Melbourne, Australia contains, for every 100ml, 9 grams of carbohydrate which is 8 grams of 'sugar'. I don't know what the other 1 gram is. They don't specify the sugar, but I expect, being orange juice, that that's pretty close to 100% fructose. I don't know for sure, it's not clear on the wikipedia entry for oranges.
Ok, so 250ml of orange juice, no 'added' sugar, what's in it? 20 grams of sugar, that's 4 teaspoons. If that's just sucrose, that's roughly 10 grams of fructose and 10 grams of glucose, but I think, from this page, that it's 100% fructose. That's quite a lot. 4 teaspoons of fructose in 250ml of orange juice. No-one would put that much in a cup of coffee or tea! It's only 7 grams less sugar than 250ml of Coca Cola. (Coke is 39 grams of sugar per 355ml, ~11% sugar, orange juice is ~8% sugar). Coca Cola in Australia uses sucrose as a sweetener, which is 50% glucose and 50% fructose. Coke is 5.5% fructose, OJ is 8% fructose. Interesting, eh?
Let's look at a little more context. Let's see how many oranges there are in a glass (again, our ficticious 250ml glass) of OJ. The average orange has about 2 ounces of OJ in it. According to this site anyway. An 8 ounce glass is about 240ml (1 US fluid Oz ~ 29.6 ml), so there's 4 and a bit's worth of oranges in a glass of OJ. so if we've got 20 grams of fructose in 250ml, and that's about 4 oranges worth, each orange has about 5 grams of fructose in it. 5 grams is one teaspoon. That's not too bad. An individual orange has about 70 mg of Vitamin C in it. That's plenty. The RDA according to the WHO is 45 mg/day. So, one orange is fine, it's only 5g of fructose and it's got all the Vit C you need. A glass of orange juice on the other hand ... In context, is almost as bad as a glass of coke, or possibly worse if you take into account that coke is using sucrose in Australia, which is only 50% fructose. Although OJ does have some good stuff in it (vit c etc) it's got WAY too much sugar in it unless you're doing a lot of heavy exercise. And this is the best case scenario! Most of the cups in my house are 300ml or more. I expect they are in your house too.
We use, in our sports drinks (Staminade) 2-3, maybe 4 at most teaspoons (mostly sugar, a bit of salt) per 750ml bidon, you'd think that was a lot of sugar, until you compare it to OJ, which is 3 times as sugar-full as our sports drink mixture. And we feed OJ to our kids telling them it's good for them and then wonder why they're all getting fat.