Wednesday, January 11, 2012

Sugar

    So I watched this video, Forks over Knives. More on that later, but I did start wondering about sugar alternatives like honey, since I've never been entirely clear on the whole business. Sugar's not good for us, but is honey much better?
    • glucose and fructose are the basic sugars.
    • sucrose (table sugar) is disaccharide made up of 50% glucose and 50% fructose; it's broken down into glucose and fructose in the digestive tract.
    • There are also maltose, lactose and other sugars that I'm not consdering here.
    Fruit and vegetables contain both sucrose, and free glucose and fructose; the proportions vary.
    • Apples and Pear have a much higher percent of fructose (total).
    • Apricots, plums, and sweetcorn have a somewhat lower percent of fructose (total).
    Considering sucrose separately:
    • relively more sucrose in apricots, peaches, pineapple, beets, carrots and sweet potatoes
    • relatively less sucrose in figs, grapes, pears, sweetcorn, sweet peppers, and sweet onion
    Other sweeteners are made of of some combination of sucrose, fructose and glucose, plus water (for liquids) and traces of this and that:
    • Honey - varies, for example: 38% fructose, 31% glucose, 7% maltose, 1% sucrose
    • Maple syrup - mostly sucrose with variable amounts of fructose and glucose
    • Agave - variable and not regulated, some sources give 92% fructose and 8% glucose; another gives 56% fructose and 20% glucose.   Agave nectar is hydrolized from agave juice by heating or using enzymes.
    • Corn sugar/dextrose - entirely glucose.  Derived from corn (via a chemical process)
    • HFCS - the one in soft drinks is 55% fructose and 42% glucose.  Derived from corn syrup via further chemical process.
    Fructose is much sweeter than glucose (so less can be used) and has a lower glyemic index, but has equivalent impact on diabetes. Unlike glucose, fructose must be metabolized by the liver and excessive amounts may cause liver problems (such as fatty liver)

    It's not clear why HFCS would be worse than sugar, but rats did gain more weight and get more unhealthy on HFCS than on plain sugar. See Princeton study on rats. They hypothesize that glucose and fructose bound together into sucrose metabolizes differently than as free glucose and fructose.

    There's a number of studies that are particularly focused on HFCS, and of course the usual it's-all-just-sugar, but I don't find the results conclusive; everyone has an agenda. Here's one analysis and an article on liver issues.

    Given my personal opinions about nutrition, and this is fairly well supported by all the information out there; the right answer is certainly "none of the above". Honey is not that different in proportion from HFCS but is the least processed, the most local, and has minerals, enzymes, and antioxidants.

    3 comments:

    Harvey Glovier said...

    As a young science, nutrition is not yet ready. Maybe the best we can do is what grand mother did. Or so sayeth Sir Michael Pollan.

    Harvey Glovier said...

    As a young science, nutrition is not yet ready. Maybe the best we can do is what grand mother did. Or so sayeth Sir Michael Pollan.

    Harvey Glovier said...

    Scientists are working on nutrition science, but food is said to have a number of mysterious ingredients of which we know nothing about.. yet.